Rapport D'activité 2007-2012

Laboratoire d’Informatique Algorithmique : Fondements et Applications

LIAFA

Rapport d’activites´ 1er janvier 2007 – 30 juin 2012

Laboratoire d’Informatique Algorithmique : Fondements et Applications (LIAFA) UMR CNRS 7089 Universite´ Paris Diderot - Paris 7 Case 7014 75205 Paris Cedex 13 Tel. +33 (0)1 57 27 92 56 Fax. +33 (0)1 57 27 94 09 [email protected] http://www.liafa.univ-paris-diderot.fr

Table des matieres`

Preambule´ 1

I Rapport et projet scientiﬁque du LIAFA 3

1 Rapport scientiﬁque du laboratoire 5

2 Projet scientiﬁque du laboratoire 29

II Algorithms and Complexity team 37

1 Research report: Algorithms and Complexity 39

2 Fiche resum´ e:´ Algorithmes et Complexite´ 45

3 Executive Summary: Algorithms and Complexity 47

4 Research project: Algorithms and Complexity 49

5 List of publications: Algorithms and Complexity 57

6 Appendix: Algorithms and Complexity 67

III Equipe Algorithmes Distribues´ et Graphes 77

1 Rapport scientiﬁque : Algorithmes Distribues´ et Graphes 79

2 Fiche resum´ e´ : Algorithmes Distribues´ et Graphes 85

3 Executive Summary : Distributed Algorithms and Graphs 87

4 Projet scientiﬁque : Algorithmes Distribues´ et Graphes 89

5 Liste des publications : Algorithmes Distribues´ et Graphes 95

6 Annexes : Algorithmes Distribues´ et Graphes 119

i TABLE DES MATIERES` IV Automata and Applications team 143

1 Research report: Automata and Applications 145

2 Fiche resum´ e:´ Automates et applications 151

3 Executive Summary: Automata and Applications 153

4 Research project: Automata and Applications 155

5 List of publications: Automata and Applications 163

6 Appendix: Automata and Applications 181

V Equipe Combinatoire 199

1 Rapport scientiﬁque : Combinatoire 201

2 Fiche resum´ e´ : Combinatoire 207

3 Executive Summary : Combinatorics 209

4 Projet scientiﬁque : Combinatoire 211

5 Liste des publications : Combinatoire 217

6 Annexes : Combinatoire 225

VI Modeling and Veriﬁcation team 231

1 Research report: Modeling and Veriﬁcation 233

2 Fiche resum´ e:´ Modelisation´ et Veriﬁcation 239

3 Executive Summary: Modeling and Veriﬁcation 241

4 Research project: Modeling and Veriﬁcation 243

5 List of publications: Modeling and Veriﬁcation 251

6 Appendix: Modeling and Veriﬁcation 265

VII Bref historique du LIAFA 279

ii Table des matieres` detaill´ ee´

Preambule´ 1

I Rapport et projet scientiﬁque du LIAFA 3

1 Rapport scientifique du laboratoire 5 1.1 Resum´ e´ des activites´ et des resultats´ de l’unite...... ´ 5 1.1.1 Faits marquants 2007-2012 ...... 5 1.1.2 A propos d’une fusion LIAFA-PPS ...... 8 1.2 Gouvernance, administration et vie scientifique ...... 8 1.2.1 Gouvernance ...... 8 1.2.2 Administration et services ...... 9 1.2.3 Vie scientifique ...... 10 1.3 Composition ...... 11 1.4 Budget ...... 14 1.5 Le LIAFA dans son environnement ...... 16 1.5.1 L’universite´ Paris Diderot, l’UFR, la Fed´ eration,´ et l’Ecole Doctorale ...... 16 1.5.2 La Fondation et le LABEX Sciences Mathematiques´ de Paris ...... 16 1.5.3 Inria, CEA et Technicolor ...... 17 1.5.4 Environnement scientifique ...... 17 1.5.5 Animation ...... 19 1.5.6 Interdisciplinarite...... ´ 19 1.6 Formation par la recherche ...... 20 1.7 Vulgarisation et diffusion scientifiques ...... 21 1.8 Valorisation ...... 21 1.9 Annexes ...... 22 1.9.1 Liste des membres permanents chercheurs et enseignants-chercheurs au 10/09/2012 . . . . 22 1.9.2 Liste des membres du conseil de laboratoire ...... 24 1.9.3 Reglement` interieur´ ...... 25 1.9.4 Charte d’utilisation des moyens informatiques ...... 27

2 Projet scientiﬁque du laboratoire 29 2.1 Positionnement scientiﬁque et objectif gen´ eral´ ...... 29

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2.2 Axes fed´ erateurs´ internes et implications externes ...... 30 2.2.1 Algorithmique ...... 31 2.2.2 Systemes` concurrents ...... 31 2.2.3 Structures et logique, jeux ...... 32 2.3 Rapprochement LIAFA-PPS ...... 33 2.3.1 Thematiques´ d’accroche ...... 33 2.3.2 Seminaire´ didactique ...... 34 2.4 Analyse SWOT ...... 35

II Algorithms and Complexity team 37

1 Research report: Algorithms and Complexity 39 1.1 Research areas and main objectives ...... 39 1.1.1 Development of the team ...... 39 1.1.2 Description of our main scientific results ...... 41 1.2 Selected results of significance ...... 42 1.2.1 Streaming algorithms for large XML databases ...... 42 1.2.2 Quantum cryptographic protocols ...... 43 1.3 Scientific service and influence, honors and prizes ...... 43 1.4 Internal organization ...... 44

2 Fiche resum´ e:´ Algorithmes et Complexite´ 45 2.1 Effectifs ...... 45 2.2 Production scientiﬁque ...... 45 2.3 Bilan quantitatif ...... 45 2.3.1 Publications ...... 45 2.3.2 Logiciels, brevets, rapports, etc...... 46 2.3.3 Rayonnement ...... 46 2.3.4 Interactions de l’equipe´ avec son environnement ...... 46 2.3.5 Actions de formation ...... 46

3 Executive Summary: Algorithms and Complexity 47 3.1 Members ...... 47 3.2 Scientiﬁc outcomes ...... 47 3.3 Quantitative assessment ...... 47 3.3.1 Publications ...... 47 3.3.2 Software, patents, reports, etc...... 48 3.3.3 Inﬂuence of the team ...... 48 3.3.4 Interactions between the team and its environment ...... 48 3.3.5 Teaching ...... 48

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4 Research project: Algorithms and Complexity 49 4.1 Research objectives ...... 49 4.1.1 Scientific outlook ...... 49 4.1.2 Our long term scientific goals: Efficiency and Security ...... 50 4.1.3 Detailed descriptoin of research objectives ...... 51 4.2 Project implementation ...... 53

5 List of publications: Algorithms and Complexity 57 ACL : Articles in international or national journals ...... 57 C-INV : Invited talks ...... 60 C-ACTI : International conference proceedings ...... 60 C-COM : International or national conferences without proceedings ...... 64 DO : Editing of journals and other works ...... 66 OS : Scientiﬁc works ...... 66 PV : Popularization works ...... 66 AP : Other works ...... 66

6 Appendix: Algorithms and Complexity 67 6.1 Composition and team organization ...... 67 6.1.1 Current members ...... 67 6.1.2 Former members ...... 68 6.1.3 Visitors ...... 69 6.1.4 Team organization ...... 69 6.2 Grants and research projects ...... 70 6.2.1 Management of international projects ...... 70 6.2.2 Management of national projects ...... 71 6.2.3 Participation in international projects ...... 71 6.2.4 Participation in local projects ...... 71 6.2.5 Participation in local projects ...... 71 6.3 Research administration ...... 71 6.3.1 Editorial duties ...... 71 6.3.2 Management of scientific conferences ...... 72 6.3.3 Organization of scientific events ...... 73 6.3.4 Participation in scientific juries and committees ...... 73 6.4 Teaching, advising, and evaluation activities ...... 74 6.4.1 Theses and HdR defended ...... 74 6.4.2 Thesis reports ...... 74 6.4.3 Teaching ...... 74

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III Equipe Algorithmes Distribues´ et Graphes 77

1 Rapport scientifique : Algorithmes Distribues´ et Graphes 79 1.1 Thematique´ gen´ erale´ et principaux objectifs ...... 79 1.1.1 Introduction ...... 79 1.1.2 Themes` de recherche ...... 80 1.2 Exemples de resultats´ significatifs ...... 80 1.3 Animation scientifique, rayonnement, prix et recompenses´ ...... 82 1.4 Fonctionnement interne ...... 83 1.5 Formation par la recherche ...... 83

2 Fiche resum´ e´ : Algorithmes Distribues´ et Graphes 85 2.1 Effectifs ...... 85 2.2 Production scientiﬁque ...... 85 2.3 Bilan quantitatif ...... 86 2.3.1 Publications ...... 86 2.3.2 Logiciels, brevets, rapports, etc...... 86 2.3.3 Rayonnement ...... 86 2.3.4 Interactions de l’equipe´ avec son environnement ...... 86 2.3.5 Actions de formation ...... 86

3 Executive Summary : Distributed Algorithms and Graphs 87 3.1 Members ...... 87 3.2 Scientiﬁc outcomes ...... 87 3.3 Quantitative assessment ...... 88 3.3.1 Publications ...... 88 3.3.2 Software, patents, reports, etc...... 88 3.3.3 Inﬂuence of the team ...... 88 3.3.4 Interactions between the team and its environment ...... 88 3.3.5 Teaching ...... 88

4 Projet scientiﬁque : Algorithmes Distribues´ et Graphes 89 4.1 Objectifs scientiﬁques ...... 89 4.1.1 Theorie´ de la calculabilite´ et de la complexite´ du calcul distribue.´ ...... 89 4.1.2 Grands reseaux´ ...... 91 4.1.3 Algorithmique de graphes ...... 93 4.1.4 Bioinformatique ...... 93 4.2 Mise en œuvre du projet ...... 94

5 Liste des publications : Algorithmes Distribues´ et Graphes 95 ACL : Articles dans des revues internationales ou nationales ...... 95 C-INV : Conferences´ invitees´ ...... 101

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C-ACTI : Communications avec actes de conferences´ internationales ...... 103 C-ACTN : Communications avec actes de conferences´ nationales ...... 114 C-COM : Communications orales sans actes en conferences´ internationales ou nationales ...... 115 DO : Directions d’ouvrages ou de revues ...... 117 OS : Ouvrages scientiﬁques ...... 117 PV : Publications de vulgarisation ...... 118 AP : Autres productions ...... 118

6 Annexes : Algorithmes Distribues´ et Graphes 119 6.1 Composition et vie scientifique ...... 119 6.1.1 Liste actuelle des membres ...... 119 6.1.2 Anciens membres ...... 120 6.1.3 Visiteurs ...... 122 6.1.4 Vie de l’equipe´ ...... 122 6.2 Contrats et projets scientifiques ...... 126 6.2.1 Responsabilites´ de projets internationaux ...... 126 6.2.2 Responsabilite´ de projets nationaux ...... 126 6.2.3 Participation a` des projets internationaux ...... 127 6.2.4 Participation a` des projets nationaux ...... 128 6.2.5 Participation a` des projets locaux ...... 128 6.3 Administration de la recherche ...... 129 6.3.1 Activitees´ editoriales´ ...... 129 6.3.2 Gestion scientifique de conferences´ ...... 129 6.3.3 Organisation d’ev´ enements` scientifiques ...... 133 6.3.4 Participant a` des comites´ et jurys scientifiques ...... 133 6.4 Activites´ de formation, encadrement et evaluation´ ...... 134 6.4.1 Liste des theses` et HdR soutenues ...... 134 6.4.2 Listes des rapports de theses` et d’habilitations ...... 135 6.4.3 Enseignement dispense...... ´ 137 6.4.4 Autres ...... 141

IV Automata and Applications team 143

1 Research report: Automata and Applications 145 1.1 Research areas and main objectives ...... 145 1.2 Selected results of significance ...... 149 1.3 Scientific service and influence, honors and prizes ...... 149 1.4 Internal organization ...... 150

2 Fiche resum´ e:´ Automates et applications 151

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2.1 Effectifs ...... 151 2.2 Production scientiﬁque ...... 151 2.3 Bilan quantitatif ...... 152 2.3.1 Publications ...... 152 2.3.2 Logiciels, brevets, rapports, etc...... 152 2.3.3 Rayonnement ...... 152 2.3.4 Interactions de l’equipe´ avec son environnement ...... 152 2.3.5 Actions de formation ...... 152

3 Executive Summary: Automata and Applications 153 3.1 Members ...... 153 3.2 Scientiﬁc outcomes ...... 153 3.3 Quantitative assessment ...... 153 3.3.1 Publications ...... 153 3.3.2 Software, patents, reports, etc...... 154 3.3.3 Inﬂuence of the team ...... 154 3.3.4 Interactions between the team and its environment ...... 154 3.3.5 Teaching ...... 154

4 Research project: Automata and Applications 155 4.1 Research objectives ...... 155 4.2 Project implementation ...... 160

5 List of publications: Automata and Applications 163 ACL : Articles in international or national journals ...... 163 C-INV : Invited talks ...... 169 C-ACTI : International conference proceedings ...... 170 C-COM : International or national conferences without proceedings ...... 179 DO : Editing of journals and other works ...... 179 OS : Scientiﬁc works ...... 179 COS : Chapters in scientiﬁc works ...... 179 PV : Popularization works ...... 180

6 Appendix: Automata and Applications 181 6.1 Composition and team organization ...... 181 6.1.1 Current members ...... 181 6.1.2 Former members ...... 182 6.1.3 Visitors ...... 184 6.1.4 Team organization ...... 184 6.2 Grants and research projects ...... 186 6.2.1 Management of international projects ...... 186

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6.2.2 Management of national projects ...... 187 6.2.3 Management of local projects ...... 187 6.2.4 Participation in international projects ...... 187 6.2.5 Participation in national projects ...... 188 6.3 Research administration ...... 189 6.3.1 Editorial duties ...... 189 6.3.2 Management of scientific conferences ...... 189 6.3.3 Organization of scientific events ...... 191 6.3.4 Participation in scientific juries and committees ...... 192 6.4 Teaching, advising, and evaluation activities ...... 193 6.4.1 Theses and HdR defended ...... 193 6.4.2 Thesis and habilitation reports ...... 194 6.4.3 Teaching ...... 196 6.4.4 Prices and distinctions ...... 197

V Equipe Combinatoire 199

1 Rapport scientifique : Combinatoire 201 1.1 Thematique´ gen´ erale´ et principaux objectifs ...... 201 1.1.1 Constitution de l’equipe´ ...... 201 1.2 Exemples de resultats´ significatifs ...... 203 1.3 Animation scientifique, rayonnement, prix et recompenses´ ...... 205 1.4 Fonctionnement interne ...... 205

2 Fiche resum´ e´ : Combinatoire 207 2.1 Effectifs ...... 207 2.2 Production scientiﬁque ...... 207 2.3 Bilan quantitatif ...... 208 2.3.1 Publications ...... 208 2.3.2 Rayonnement ...... 208 2.3.3 Actions de formation ...... 208

3 Executive Summary : Combinatorics 209 3.1 Members ...... 209 3.2 Scientiﬁc outcomes ...... 209 3.3 Quantitative assessment ...... 210 3.3.1 Publications ...... 210 3.3.2 Software, patents, reports, etc...... 210 3.3.3 Inﬂuence of the team ...... 210 3.3.4 Teaching ...... 210

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4 Projet scientifique : Combinatoire 211 4.1 Objectifs scientifiques ...... 211 4.1.1 Auto-evaluation´ ...... 211 4.1.2 Evolution par rapport a` la periode´ prec´ edente´ ...... 211 4.1.3 Objectifs de l’equipe´ ...... 211 4.1.4 Programme prevu´ dans le contexte local, national et international ...... 212 4.1.5 Prospective, positionnement dans la communaute´ scientifique, et evolution´ a` moyen terme 212 4.1.6 Prospective, positionnement dans la communaute´ scientifique, d’evolution´ a` long terme . . 213 4.2 Mise en œuvre du projet ...... 214 4.2.1 Politique scientifique ...... 214 4.2.2 Partenariats dans la recherche et l’enseignement superieur´ ...... 214 4.2.3 Vie de l’equipe´ ...... 214 4.2.4 Recherche de moyens ...... 215 4.2.5 Diffusion des resultats´ ...... 215

5 Liste des publications : Combinatoire 217 ACL : Articles dans des revues internationales ou nationales ...... 217 C-INV : Conferences´ invitees´ ...... 220 C-ACTI : Communications avec actes de conferences´ internationales ...... 220 C-COM : Communications orales sans actes en conferences´ internationales ou nationales ...... 222

6 Annexes : Combinatoire 225 6.1 Composition et vie scientifique ...... 225 6.1.1 Liste actuelle des membres ...... 225 6.1.2 Anciens membres ...... 226 6.1.3 Visiteurs ...... 226 6.1.4 Vie de l’equipe´ ...... 226 6.2 Contrats et projets scientifiques ...... 227 6.2.1 Responsabilite´ de projets nationaux ...... 227 6.2.2 Participation a` des projets internationaux ...... 227 6.2.3 Participation a` des projets nationaux ...... 227 6.3 Administration de la recherche ...... 228 6.3.1 Activites´ editoriales´ ...... 228 6.3.2 Gestion scientifique de conferences´ ...... 228 6.3.3 Organisation d’ev´ enements´ scientifiques ...... 228 6.3.4 Participant a` des comites´ et jurys scientifiques ...... 228 6.4 Activites´ de formation, encadrement et evaluation´ ...... 229 6.4.1 Liste des theses` et HdR soutenues ...... 229 6.4.2 Enseignement dispense...... ´ 229

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VI Modeling and Veriﬁcation team 231

1 Research report: Modeling and Veriﬁcation 233 1.1 General context and objectives ...... 233 1.2 Main results in the period 2007-2012 ...... 233 1.3 Scientiﬁc services, international visibility, and collaborations ...... 236 1.4 Internal organization and management ...... 237

2 Fiche resum´ e:´ Modelisation´ et Veriﬁcation 239 2.1 Effectifs ...... 239 2.2 Production scientiﬁque ...... 239 2.3 Bilan quantitatif ...... 240 2.3.1 Publications ...... 240 2.3.2 Logiciels, brevets, rapports, etc...... 240 2.3.3 Rayonnement ...... 240 2.3.4 Interactions de l’equipe´ avec son environnement ...... 240 2.3.5 Actions de formation ...... 240

3 Executive Summary: Modeling and Verification 241 3.1 Members ...... 241 3.2 Scientific outcomes ...... 241 3.3 Quantitative assessment ...... 242 3.3.1 Publications ...... 242 3.3.2 Software, patents, reports, etc...... 242 3.3.3 Influence of the team ...... 242 3.3.4 Interactions between the team and its environment ...... 242 3.3.5 Educational activities ...... 242

4 Research project: Modeling and Veriﬁcation 243 4.1 Introduction ...... 243 4.2 Reasoning about complex data structures ...... 244 4.3 Concurrent and distributed systems ...... 245 4.4 Malware detection ...... 246 4.5 Quantitative Reasoning ...... 247 4.6 Implementation of the project ...... 247

5 List of publications: Modeling and Veriﬁcation 251 ACL : Articles in international or national journals ...... 251 C-INV : Invited talks/papers in international conferences and workshops ...... 253 C-ACTI : International conference proceedings ...... 253 C-ACTI : International workshop proceedings ...... 262 C-COM : Talks at conferences without proceedings or upon-invitation-only meetings ...... 262

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DO : Editing of journals and other works ...... 263 COS : Chapters in scientiﬁc works ...... 263

6 Appendix: Modeling and Verification 265 6.1 Composition and team organization ...... 265 6.1.1 List of current members ...... 265 6.1.2 Former members ...... 266 6.1.3 Visitors ...... 267 6.1.4 Team organization ...... 267 6.2 Grants and research projects ...... 269 6.2.1 Coordination of international projects ...... 269 6.2.2 Coordination of national projects ...... 269 6.2.3 Participation in international projects ...... 269 6.2.4 Participation in national projects ...... 270 6.3 Research administration ...... 270 6.3.1 Editorial activities ...... 270 6.3.2 Scientific management of conferences ...... 270 6.3.3 Organization of scientific events ...... 273 6.3.4 Participation in scientific juries and committees ...... 273 6.4 International visibility ...... 274 6.4.1 Invited talks ...... 274 6.4.2 Participation in upon-invitation-only scientific meetings ...... 275 6.4.3 Invited stays ...... 275 6.5 Educational, advising, and evaluation activities ...... 276 6.5.1 List of defended PhD theses and Habilitations ...... 276 6.5.2 Reports on PhD and Habilitation theses ...... 277 6.5.3 Educational activities ...... 278

VII Bref historique du LIAFA 279

xii Preambule´

Ce document decrit´ les activites´ scientifiques et administratives du Laboratoire d’Informatique Algorith- mique : Fondements et Applications (LIAFA), UMR 7089 CNRS – Universite´ Paris Diderot (Paris 7), pour la periode´ allant de janvier 2007 a` juin 2012 (voir historique du laboratoire en partie VII). Il inclut en Partie I un bilan scientifique et administratif des activites´ du laboratoire durant cette periode,´ ainsi qu’une description du projet scientifique gen´ eral´ du LIAFA pour le prochain quinquennat. La description detaill´ ee´ des activites´ scientifiques de chacune des equipes´ de recherche du LIAFA est fournie dans les rapports des cinq equipes´ du laboratoire, dans les cinq parties suivantes II a` VI du document. Chaque rapport d’equipe´ inclut un bilan detaill´ e´ des activites´ de l’equipe´ sur la periode´ couverte par le rapport, ainsi qu’un projet de recherche detaill´ e,´ specifique´ a` l’equipe,´ pour le prochain quinquennat.

Je tiens a` remercier tous les membres du laboratoire, les chercheurs, enseignants-chercheurs, doctorants et post-doctorants, ainsi que le personnel administratif et technique. Le LIAFA ne saurait etreˆ ce qu’il est sans la participation active de chacun d’entre eux, et je tiens a` exprimer le plaisir que j’ai eu et la fierte´ que j’eprouve´ a` exercer la responsabilite´ d’un tel laboratoire. Je tiens egalement´ a` remercier les responsables des cinq equipes´ de recherche du laboratoire, Ahmed Bouajjani, Sylvie Corteel, Carole Delporte, Miklos Santha, et Olivier Serre, pour le travail considerable´ qu’ils ont fourni lors de la redaction´ de ce rapport. Je souhaite egalement´ exprimer ma reconnaissance a` Enrica Duchi, Peter Habermehl, Fred´ eric´ Magniez, Fabien Mathieu et Olivier Serre pour leur aide absolument indispensable et le travail precieux´ qu’ils ont fourni pour collecter et gerer´ les publications de tous les membres du laboratoire. Je souhaite tout particulierement` exprimer ma profonde gratitude envers Fred´ eric´ Magniez et Olivier Serre pour leur implication dans la redaction´ de ce document. Leur aide scientifique et technique n’a pas seulement et´ e´ precieuse,´ elle a et´ e´ absolument cruciale, et ce document n’aurait pas pu voir le jour sans leur implication. Je tiens bien surˆ aussi a` exprimer le plaisir immense que j’ai pris a` travailler avec Valerie´ Berthe,´ directrice adjointe du laboratoire, non seulement pour la redaction´ de ce document mais aussi tout au long de notre collaboration a` la direction du laboratoire. Je tiens enfin tout particulierement` a` remercier tres` chaleureusement Noelle¨ Delgado, pour le travail considerable´ et souvent tres` delicat´ de collecte de donnees´ qu’elle a duˆ fournir pour la redaction´ des documents administratifs et financiers liees´ a` ce rapport. Son implication a et´ e´ absolument essentielle.

31/08/2012 Pierre Fraigniaud Directeur du LIAFA

1 TABLE DES MATIERES` DETAILL´ EE´

2 Partie I

Rapport et projet scientiﬁque du LIAFA

Chapitre 1

Rapport scientiﬁque du laboratoire

1.1R esum´ e´ des activites´ et des resultats´ de l’unite´

Le Laboratoire d’Informatique Algorithmique : Fondements et Applications (LIAFA) est une unite´ mixte de recherche (UMR 7089) du Centre National de la Recherche Scientiﬁque (CNRS) et de l’Universite´ Paris Diderot - Paris 7. Le laboratoire compte actuellement 60 membres permanents, se repartissant´ en 34 enseignant-chercheurs, 24 chercheurs CNRS et 2 chercheurs INRIA. L’effectif total du laboratoire, incluant doctorants, post-doctorants, personnel administratif et technique, et visiteurs de longue duree´ s’el´ eve` a` pres` de 110 personnes (voir section 1.3). Les principales thematiques´ de recherche du LIAFA ont trait a` l’informatique fondamentale, et se declinent´ autour de cinq equipes´ de recherche : • Algorithmes et complexite´ – responsable : Miklos Santha (DR CNRS) • Algorithmique distribuee´ et graphes – responsable : Carole Delporte (Professeur) • Automates et applications – responsable : Olivier Serre (CR CNRS) • Combinatoire – responsable : Sylvie Corteel (DR CNRS) • Modelisation´ et veriﬁcation´ – responsable : Ahmed Bouajjani (Professeur) Le LIAFA est membre de la Fondation Sciences Mathematiques´ de Paris (SMP), et membre du LA- BEX Sciences Mathematiques´ de Paris issu de cette fondation. Le LIAFA est egalement´ membre de la Fed´ eration´ de Recherche en Mathematiques´ Paris centre (FR2830) du CNRS. Il heberge´ l’equipe-projet´ INRIA ¾ GANG ¿ au sein de l’equipe´ Algorithmique distribuee´ et graphes. La direction du laboratoire durant la periode´ couverte par ce rapport a et´ e´ exercee´ successivement par Jean-Eric Pin, jusqu’a` decembre´ 2007, puis par Michel Habib de janvier 2008 a` decembre´ 2009, et, depuis janvier 2010, par Pierre Fraigniaud.

1.1.1 Faits marquants 2007-2012

• Environ 380 publications dans des revues internationales, et environ 430 publications dans des actes de conferences´ internationales 1. • 12 ¾ Best Paper Award ¿, aux conferences´ SPAA 2007, ICALP 2008, CIAA 2008, DISC 2009, FORMATS 2009, FPSAC 2009 (¾ best student paper award ¿), ICDCN 2009, DISC 2011, ICALP 2011, Int. Conf. on Petri Nets 2011, ETAPS 2012, et ICDT 2012 (¾ best newcomer paper ¿). • Deux ¾ Starting Grants ¿ de l’ERC : Thomas Colcombet (2010) et Iordanis Kerenidis (2012 2). • Responsabilite´ de deux Laboratoires Europeens´ Associes´ (LEA) : • STRUCO avec Charles University, Prague (Jean-Sebastien´ Sereni, CR CNRS). • FILOFOCS avec Tel-Aviv University (Adi Rosen,´ DR CNRS). • Medaille´ de bronze CNRS 2010 (Thomas Colcombet, CR CNRS) et medaille´ d’argent CNRS 2012 (Pierre Fraigniaud, DR CNRS).

1. Soit pres` de trois publications par an et par permanents, sur la base de 60 permanents durant le quinquennat. 2. Debut´ ofﬁciel du projet : 1er janvier 2013.

5 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE

Dem´ enagement´ interne a` Chevaleret (septembre 2010). Le retour des laboratoires de mathematiques´ de l’UPMC sur le campus de Jussieu a liber´ e´ des locaux a` Chevaleret, ce qui a permis au LIAFA, apres` restructuration, de gagner en surface a` la rentree´ 2010. Le LIAFA devrait entrer dans ses locaux definitifs´ du batimentˆ Sophie Germain 3 du campus de l’universite´ Paris Diderot fin 2012 - debut´ 2013 (voir figures 1.1 et 1.2). Ce dernier dem´ enagement´ devrait enfin resoudre,´ au moins pour un temps, un probleme` recurrent´ d’espace empoisonnant la vie du LIAFA depuis de nombreuses annees.´ 4

FIGURE 1.1 – Le batimentˆ Sophie Germain (emplacement marque´ d’une croix rouge)

Creation´ de l’equipe´ Combinatoire (janvier 2011). Le conseil de laboratoire du LIAFA a donne´ son accord fin 2010 pour la creation´ de l’equipe´ Combinatoire. Cette creation´ reconnaissait l’emergence´ d’une activite´ importante et pleinement autonome au sein du LIAFA sur cette thematique,´ et repondait´ a` la necessit´ e´ d’affirmer vis-a-vis` de l’exterieur´ l’activite´ combinatoire au LIAFA. Accueil de l’equipe´ Algorithmes et complexite´ (novembre 2010). La restructuration des locaux de Chevaleret a` la rentree´ 2010 mentionnee´ ci-dessus a permis de finaliser fin 2010 une operation´ scientifique d’envergure, a` savoir, la mutation au LIAFA de six membres du LRI : Michel De Rou- gemont (Pr, Pantheon-Assas), Julia Kempe (DR CNRS), Iordanis Kerenidis (CR CNRS), Fred´ eric´ Magniez (DR CNRS), Adi Rosen´ (DR CNRS), et Miklos Santha (DR CNRS). L’arrivee´ de ces chercheurs au LIAFA a naturellement conduit le laboratoire a` creer´ une cinquieme` equipe´ : Al- gorithmes et complexite.´ Cette operation´ strategique´ d’importance repondait´ au besoin pour le LIAFA de developper´ des activites´ consequentes´ en algorithmique. Elle n’aurait pu etreˆ menee´ a` bien sans une coordination constructive de la part du CNRS lors des negociations´ entre le LRI et le LIAFA 5. L’universite´ Paris Diderot a fortement soutenu cette operation´ scientifique en repondant´ positivement a` la demande de l’UFR Informatique de creation´ d’un poste de professeur sur les themes` de la nouvelle equipe.´ Cette creation´ a ainsi permis de finaliser la mutation de l’equipe´ de Paris Sud a` Paris Diderot graceˆ au recrutement en juin 2012 de Sophie Laplante (Pr Paris Diderot).

3. Marie-Sophie Germain (1776-1831) est l’une des premieres` mathematiciennes´ françaises. Autodidacte, elle se procure les cours de l’Ecole´ polytechnique, reserv´ ee´ aux hommes, en empruntant l’identite´ d’un ancien el´ eve.` Elle envoie ses remarques a` Joseph-Louis Lagrange, qui finit par decouvrir´ l’imposture en la convoquant du fait de ses brillantes reponses.´ (Source : Wikipedia).´ 4. Toutes les negociations´ avec l’universite´ Paris Diderot liees´ aux locaux pour l’informatique ont et´ e´ menees´ par François Laroussinie et Jean-Marie Rifflet pour l’UFR Informatique, Thomas Ehrhard pour PPS et Pierre Fraigniaud pour le LIAFA. 5. Pierre Fraigniaud tient a` exprimer toute sa reconnaissance envers Philippe Dague (directeur du LRI) qui, par sa courtoisie, a permis aux negociations´ entre les deux laboratoires, sous couvert du CNRS, de se derouler´ dans un climat de parfaite ser´ enit´ e.´

6 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE

FIGURE 1.2 – Le campus de l’universite´ Paris Diderot

7 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE

1.1.2 A propos d’une fusion LIAFA-PPS

Mi-2010, l’institut INS2I du CNRS a invite´ les directeurs des deux laboratoires LIAFA et PPS a` en- gager des discussions afin d’envisager une potentielle fusion des deux unites,´ idealement´ a` l’horizon 2014. Cette demande etait´ motivee´ par la proximite´ thematique´ entre les deux laboratoires, tous deux focalises´ sur des thematiques´ d’informatique fondamentale. Un des objectifs principaux etait´ ainsi de creer´ une unite´ d’Informatique avec une forte visibilite´ au sein de l’Universite´ Paris Diderot couvrant une grande partie du spectre de l’Informatique Fondamentale. Cette invitation a conduit a` la constitution d’un comite´ ¾ fusion ¿ constitue´ de Valerie´ Berthe´ (LIAFA), Pierre-Louis Curien (PPS), Roberto Di Cosmo (PPS), Thomas Ehrhrard (PPS), Pierre Fraigniaud (LIAFA), François Laroussinie (LIAFA), Anne Micheli (LIAFA), Olivier Serre (LIAFA), et Daniele Varacca (PPS). Ce comite´ a pendant plusieurs mois refl´ echi´ aux avantages et inconvenients´ d’une fusion LIAFA-PPS, ainsi qu’au mode de fonctionnement d’une potentielle unite´ resultant´ de la fusion des deux laboratoires. Il a redig´ e´ debut´ 2012 un compte-rendu detaill´ e´ de ses discussions, resumant´ ces avantages et inconvenients,´ diffuse´ a` l’ensemble des membres des deux laboratoires. Tres` sommairement, les conclusions du rapport soulignent l’avan- tage d’un gain en visibilite´ en cas de fusion, avec comme inconvenient´ majeur de devoir faire cohabiter deux structures aux modes de fonctionnement tres` differents.´ Ce compte-rendu a et´ e´ discute´ en AG dans chacun des deux laboratoires en mars 2012. Sont apparues durant ces discussions une inquietude´ majeure concernant les differences´ entre les structures et les fonctionnements respectifs des deux laboratoires, ainsi que des craintes concernant le positionnement Math-Info du laboratoire PPS. Les directions des deux laboratoires se sont neanmoins´ ouvertement prononcees´ en faveur de la fusion et ont explique´ leur position dans une lettre commune diffusee´ a` l’ensemble des membres des deux laboratoires. Les membres permanents du LIAFA et de PPS ont et´ e´ invites´ a` voter le 4 avril 2012 dans chacun de leur laboratoire, pour ou contre la fusion au 01/01/2014. Les resultats´ du vote ont et´ e´ ¾ oui ¿ a` la fusion pour 60% des 48 bulletins exprimes´ au LIAFA, et ¾ non ¿ a` la fusion pour 59% des 32 bulletins exprimes´ a` PPS. Ces resultats´ ont conduit les directeurs des deux laboratoires a` rejeter la fusion puisque celle-ci ne recueillait pas l’assentiment de chacune des deux unites.´ Il ressort toutefois des discussions informelles ou lors des AG que le vote ¾ non ¿ etaient´ souvent motives´ par l’absence de collaborations scientifiques effectives entre les deux laboratoires. Cet etat´ de fait reel´ ne reflete` neanmoins´ pas le potentiel de collaborations existant entre le LIAFA et PPS. Les deux laboratoires ont donc entrepris de laisser de cotˆ e´ les aspects administratifs lies´ aux structures, et de travailler sur les points d’accroche scientifique. Un comite´ scientifique (incluant des membres de l’equipe´ Logique de l’IMJ), co-presid´ e´ par Paul-Andre´ Mellies (PPS) et Olivier Serre (LIAFA), a ainsi et´ e´ creé´ en mai 2012 dans le but de lancer et de developper´ des actions inter-laboratoires. Le travail de ce comite´ a permis de rediger´ un projet scientifique commun aux deux unites,´ inclus dans leurs rapports d’activites´ respectifs. Ce texte se trouve en section 2.3 du present´ rapport.

1.2 Gouvernance, administration et vie scientiﬁque

1.2.1 Gouvernance

La direction du laboratoire est assuree´ par son directeur, Pierre Fraigniaud, assiste´ d’une directrice adjointe, Valerie´ Berthe´ (voir l’organigramme en ﬁgure 1.3). La direction est conseillee´ par un conseil de direction qui reunit,´ outre le directeur et la directrice adjointe, les responsables des equipes´ du laboratoire (voir section 1.1). Ce conseil aide la direction pour la prise de decisions´ rapides (arbitrage entre demandes de ressources, affectation des bureaux, etc.). Il permet la diffusion de l’information de la direction vers les equipes,´ et de faire remonter tous types de demandes des equipes´ a` la direction. Le conseil de laboratoire est en charge des decisions´ administratives ou scientiﬁques engageant le laboratoire sur le long terme (creation´ d’equipe,´ election´ du directeur, etc.). Souvent organise´ en AG du laboratoire, il permet egalement´ la diffusion de l’information de la direction directement vers les membres de l’unite.´

8 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE

Direction du laboratoire - Pierre Fraigniaud (directeur) - Valérie Berthé (directrice adjointe)

Conseil de direction Conseil de laboratoire Direction + responsables d'équipes Direction + membres élus

Equipe Algorithmes et complexité Service administratif Responsable : Miklos Santha Responsable : Noelle Delgado Equipe Algorithmique distribuée et graphes Service informatique Responsable : Carole Delporte Responsable : Laifa Ahmadi Equipe Automates et applications Responsable : Olivier Serre Commissions : - matériel Equipe Combinatoire - web Responsable : Sylvie Corteel - doctorants Equipe Modélisation et vérification - locaux Responsable : Ahmed Bouajjani - bibliothèque - etc.

FIGURE 1.3 – Organigramme du LIAFA

Outre les differents´ conseils mentionnes´ ci-dessus, la diffusion de l’information s’effectue directement de la direction aux membres du laboratoire (permanents et/ou non-permanents, selon le type d’information) par courrier electronique´ via les differentes´ listes de diffusion du LIAFA. Les informations diffusees´ incluent entre autres les appels relatifs aux allocations de these,` les appels a` projets (Europe, ANR, Region´ IdF, Ville de Paris, etc.), les offres de bourses post-doctorales, et, bien surˆ les differents´ programmes de la Fondation Sciences Mathematiques´ de Paris.

1.2.2 Administration et services

Le laboratoire dispose d’un secretariat´ , compose´ de Noelle¨ Delgado (AI CNRS), responsable administrative, et de Nathalie Rousseau 6 (AJT CNRS), secretaire´ gestionnaire. Le secretariat´ est en charge de toutes les tachesˆ administratives et financieres` liees´ au fonctionnement du LIAFA, dont en particulier la gestion des missions, la gestion financiere` de l’ensemble des contrats, et la gestion financiere` des personnels sur contrat (doctorants, post-doctorants, invites,´ etc.). Le service informatique du LIAFA est compose´ de Laifa Ahmadi (IR CNRS) et de Houy Kuoy (IE CNRS). Il a principalement en charge la gestion du reseau´ et des terminaux legers´ (TX), la gestion des serveurs de fichiers et des sauvegardes, et l’aide aux utilisateurs, dont en particulier les demandes de de- vis pour l’achat de materiels´ individuels sur ressources propres. Notons que le LIAFA a recemment´ rejoint la plateforme informatique visant a` fed´ erer´ la gestion informatique entre les laboratoires de mathematiques´ et d’informatique devant rejoindre le batimentˆ Sophie Germain du campus de Paris Di- derot. La migration de la gestion de la messagerie et du web 7 est effectuee,´ et la migration des serveurs de fichiers devrait se faire au second semestre 2012. Le LIAFA possede` egalement´ un ensemble de commissions en charge de questions specifiques´ :

• Commission ¾ materiel´ ¿ : arbitrage et prospective relatifs aux achats de materiel´ informatique

6. Recrutement NOEMI, juillet 2010. 7. Incluant le passage des adresses liafa.jussieu.fr aux adresses liafa.univ-paris-diderot.fr.

9 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE

pour le laboratoire — president´ : Fabien de Montgolﬁer (MdC, Paris Diderot). • Commission ¾ web ¿ : en charge des pages web du laboratoire — president´ : David Xiao (CR CNRS), inclus les responsables communication du laboratoire (voir ci-apres).` • Commission ¾ doctorants ¿ : points de contact pour les doctorants 8 — Coordinatrice : Valerie´ Berthe´ (DR CNRS). • Commission ¾ locaux ¿ : decide´ de l’affectation des bureaux aux membres — president´ : Pierre Fraigniaud (DR CNRS) et composee´ de Franc¸ois Laroussinie (Pr, Paris Diderot), Noelle¨ Delgado (AI CNRS), un(e) representant(e)´ par equipe,´ un(e) representant(e)´ doctorant. • Commission ¾ bibliotheque` ¿ : en charge des achats relatifs a` la bibliotheque` math-info de l’universite´ — correspondant pour le LIAFA : Olivier Serre (CR CNRS).

Par ailleurs le laboratoire s’est dote´ d’un service de communication sous la responsabilite´ scientiﬁque de Sylvie Corteel et la responsabilite´ administrative de Noelle¨ Delgado. Enﬁn, le laboratoire dispose d’un comite´ hygiene` et securit´ e´ dont le correspondant est Noelle¨ Delgado, et les ACMO Noelle¨ Delgado (AI CNRS), Fred´ eric´ Magniez (DR CNRS), et Christian Konrad (doctorant).

1.2.3 Vie scientiﬁque

La vie scientiﬁque du laboratoire est essentiellement centree´ autour de ses equipes´ de recherche, et en particulier des seminaires´ hebdomadaires et des groupes de travail de ces equipes.´ Il convient de noter que les seminaires´ des equipes´ sont publics et ouverts a` tous, membres du laboratoire ou exterieurs.´ Ces seminaires´ jouent ainsi un roleˆ de passerelles entre les equipes,´ en particulier pour les membres du laboratoires dont les themes` de recherche se situent a` l’interface entre plusieurs equipes.´ Outre ces seminaires´ d’equipe,´ notons que de nombreux groupes de travail et groupes de lecture sont organises´ au sein du laboratoire. Les seminaires´ hebdomadaires d’equipe´ sont les suivants :

• Seminaire´ ¾ Algorithmes et complexite´ ¿, mardi 11h – responsable Adi Rosen.´ • Seminaire´ ¾ Algorithmique distribuee´ et graphes ¿, mardi 14h – responsable Pierre Charbit. • Seminaire´ ¾ Automates ¿, vendredi 14h30 – responsables Christiane Frougny et Sylvain Perifel. • Seminaire´ ¾ Combinatoire enum´ erative´ et analytique ¿, jeudi 12h – responsables Sylvie Corteel et Vlady Ravelomanana. • Seminaire´ ¾ Veriﬁcation´ ¿, lundi 11h – responsables Ahmed Bouajjani et Constantin Enea.

Les frontieres` entre les equipes´ sont de fait extremementˆ poreuses, et les exemples ne manquent pas de passages d’un membre du laboratoire d’une equipe´ a` une autre. Il est a` souligner que les decoupages´ entre les equipes,´ qui se sont faits naturellement sur des bases principalement scientiﬁques, reposent egalement´ sur des bases historiques (par exemple, entre les equipes´ Algorithmes et complexite´ et Algo- rithmique distribuee´ et graphes). Il n’est ainsi pas a` exclure des modiﬁcations dans les annees´ a` venir concernant le decoupage´ entre equipes.´ Le groupe de travail ¾ Complexite´ ¿, anime´ pendant presque deux ans par Sylvain Perifel, et reunissant´ des membres de toutes les equipes´ du laboratoire, est un exemple typique de travaux inter-equipes´ au sein du laboratoire 9. D’autres groupes de travail inter- equipes,´ sur les systemes` dynamiques et sur les jeux, devraient prochainement voir le jour. Les participations inter-equipes´ a` des projets ANR sont loin d’etreˆ l’exception ; notons par exemple les projets

8. A distinguer de l’evaluation´ des etudiants´ a` mi-parcours, mise en place par l’ED, en coordination avec le laboratoire. Les membres de cette commission sont de jeunes membres du laboratoire aupres` desquels les doctorants ne devraient pas hesiter´ a` se conﬁer en cas de problemes` : Guillaume Chapuy (CR CNRS), Mihaela Sighireanu (MdC), Fred´ eric´ Magniez (DR CNRS). 9. Ce GT s’est principalement organise´ sous la forme d’un groupe de lecture du livre d’Arora et Barak Computational Complexity : a Modern Approach, 2009, sur la complexite.´ Il reunissait´ des membres du LIAFA et de l’equipe´ de logique mathematique´ de l’IMJ, plus quelques exterieurs.´ Il s’est reuni´ une petite trentaine de fois entre mars 2010 a` debut´ 2011.

10 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE

¾ Blancs ¿ NeTOC, RDAM et AlgoPol, les deux premiers entre l’equipe´ Algorithmes et complexite´ et l’equipe´ Algorithmique distribuee´ et graphes, et le troisieme` entre l’equipe´ Algorithmique distribuee´ et graphes et l’equipe´ Automates et applications. Il convient enﬁn de souligner l’existence d’un seminaire´ ¾ Thesards´ ¿, commun aux laboratoires LIAFA et PPS. Ce seminaire´ est destine´ en priorite´ aux doctorants et a, en particulier, vocation a` les ouvrir a` la diversite´ des themes` de recherche en informatique fondamentale. Enﬁn, le LIAFA organise chaque annee´ une journee´ des entrants, qui peut en fait devoir se derouler´ sur plusieurs jours, sous la responsabilite´ actuelle de Florian Horn (CR CNRS). Durant cette ou ces journees,´ les nouveaux entrants au laboratoire, enseignants-chercheurs, chercheurs, doctorants, post- doctorants, visiteurs de longue duree,´ sont invites´ a` presenter´ leur travaux, brievement` bien surˆ lorsqu’il s’agit d’un doctorant n’ayant pas encore debut´ e´ sa these.` 1.3 Composition

Le laboratoire a considerablement´ evolu´ e´ en taille dans la periode´ 2007-2012, passant d’environ 70 membres en 2007 a` presque 110 membres en 2012 (voir la ﬁgure 1.4 et la liste exhaustive des membres permanents en section 1.9.1).

120

Divers 100 Post Doc 80 Doct

60 ITA CR 40 DR

20 MdC Pr 0 2007 2008 2009 2010 2011 2012

FIGURE 1.4 – Effectif complet du LIAFA

Cet accroissement de l’effectif du LIAFA est principalement lie´ a` la conjonction de trois phenom´ enes` : 1. la poursuite d’une politique volontariste de recrutement CNRS, 2. l’arrivee´ de l’equipe´ “Algorithmes et complexite”´ au 1er novembre 2010, 3. l’accroissement du nombre de doctorants et de post-doctorants. Le LIAFA s’implique tres` fortement, tant pour attirer d’excellents candidats, que pour les aider a` presenter´ leur candidature lors des concours de recrutement CNRS. Cette politique volontariste, conjuguee´ au soutien du CNRS, a ainsi permis le recrutement de 8 CR 10 et 1 DR 11 entre 2007 et 2011. Notons neanmoins´ qu’en 2012, comme dej´ a` partiellement en 2011, le CNRS a mis en œuvre une reaffectation´ systematique´ dans d’autres laboratoires des recrues CR present´ ees´ par le LIAFA. Si le laboratoire comprend la politique d’affectation du CNRS visant a` repartir´ les ressources entre les laboratoires, il tient a` souligner que la qualite´ des candidats soutenus par le LIAFA resulte´ de l’attractivite´ du laboratoire a` l’etranger´ 12 et aupres` des grands laboratoires nationaux, et de la formation rec¸ue par les candidats lors, typiquement, d’un sejour´ post-doctoral d’un ou deux ans au LIAFA. Ainsi, le laboratoire tient a` exprimer son inquietude´ quant a` la poursuite de la politique systematique´ de reaffectation´ mis en

10. Laurent Bienvenu, Guillaume Chapuy, Florian Horn, Łukasz Kaiser, Amos Korman, Jean-Sebastien´ Sereni, Nicolas Trotignon, et David Xiao. 11. Mai Gehrke. 12. Parmi les derniers recrutements CNRS au LIAFA, on trouve un americain,´ un israelien,´ un polonais et une hollandaise, ayant tous effectue´ leur these` a` l’etranger.´

11 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE

œuvre par le CNRS en 2012, qui pourrait conduire a` reduire´ l’attractivite´ du LIAFA. Un equilibre´ devra donc etreˆ trouve´ dans les prochaines annees´ entre la politique gen´ erale´ de recrutement de l’INS2I et la politique speciﬁque´ de recrutement du LIAFA 13.

20 18 16 14 Pr 12 10 MdC 8 DR 6 CR 4 2 0 2007 2008 2009 2010 2011 2012

FIGURE 1.5 – Effectifs LIAFA : permanents

L’arrivee´ de l’equipe´ “Algorithmes et complexite”´ a et´ e´ present´ ee´ dans la section 1.1. Plusieurs mutations vers le laboratoire 14 ont egalement´ eu lieu dans la memeˆ periode.´ Il en resulte´ que de 20% des membres en 2007, presque 40% des membres du laboratoire en 2012, sont CNRS (voir la figure 1.5), pour un effectif total d’environ 60 chercheurs et enseignants-chercheurs. En particulier, l’accroissement du nombre de DR est duˆ a` la conjonction de plusieurs faits : arrivee´ de l’equipe´ “Algorithmes et complexite”,´ recrutement DR2 (Mai Gehrke), mutations (Valerie´ Berthe),´ et promotions internes (Nicolas Schabanel et Sylvie Corteel). Aux deux phenom´ enes` mentionnes´ ci-dessus s’ajoute le doublement du nombre de doctorants et de post-doctorants au sein du laboratoire (voir la figure 1.6), passant d’un vingtaine a` une quarantaine, augmentant par la` le taux d’encadrement 15 de 1,0 a` 1,2 entre 2007 et 2012, malgre´ la croissance du nombre d’habilites´ d’une vingtaine a` plus de trente dans la memeˆ periode.´ A cet accroissement s’ajoute la presence´ d’une petite dizaine de post-doctorants dans le laboratoire depuis deux ans, pour la plupart etrangers.´ Ce phenom´ ene` est principalement lie´ a` la presence´ de la Fondation SMP et a` la participation du LIAFA au LABEX eponyme´ (voir la section 1.5), et au succes` des membres du laboratoire aupres` de l’ANR et de l’ERC. Le laboratoire a en particulier augmente´ la diversite´ d’origine de ses doctorants, incluant de nombreux etudiants´ etrangers,´ parfois en co-tutelle. La figure 1.7 ne reflete` pas encore d’augmentation du nombre de soutenances de doctorats puisque les etudiants´ entres´ en these` en 2011 ou 2012 n’ont evidemment´ pas encore soutenu. Le relativement faible nombre d’HDR soutenues doit etreˆ rapporte´ au fait que presque la moitie´ des membres du laboratoire ont moins de 40 ans, dont 11 recrutes´ durant les cinq dernieres` annees.´ (Notons que deux des theses` soutenues en 2012 le seront en septembre, et les deux HDR 2012 seront soutenues au second semestre.) Notons egalement´ que le laboratoire accueille, en moyenne annuelle, une dizaine d’invites´ de moyenne duree´ (1 a` 2 mois), gen´ eralement´ finances´ par l’universite´ Paris Diderot (rubrique ¾ professeurs invites´ ¿), par la fondation SMP, ou directement par les equipes´ sur leurs ressources propres, et non comp- tabilises´ dans la figure 1.4.

13. Notons de surcroˆıt que les CR CNRS recrutes´ au LIAFA n’ont pas forcement´ vocation a` effectuer toute leur carriere` au laboratoire, comme en temoignent´ les mutations recentes,´ pour des raisons a` la fois familiales et scientiﬁques, d’un CR1 (Nicolas Trotignon) en 2011 au LIP, et d’un CR2 (Jean-Sebastien´ Sereni) en 2012 au LORIA. Ces departs´ se rajoutent a` celui d’une CR2 (Emmanuelle Lebhar) en 2010 vers l’education´ nationale. 14. Valerie´ Berthe,´ Thomas Colcombet, Sylvie Corteel, Mathieu Rafﬁnot, Nicolas Schabanel. 15. Nombre d’etudiants´ membres du laboratoire a` l’annee´ x divise´ pas le nombre de permanents habilites´ du laboratoire a` cette memeˆ annee´ x. Notons que de nombreuses theses` sont en fait co-encadrees´ par un-e non habilite-e.´

12 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE

45 40 35 30 25 Doct 20 Post Doc 15 10 5 0 2007 2008 2009 2010 2011 2012

FIGURE 1.6 – Effectifs LIAFA : doctorants et post-doctorants

4 Thèses

3 HDR

0 2007 2008 2009 2010 2011 2012

FIGURE 1.7 – Nombre de theses` et HDR soutenues

La figure 1.5 montre egalement´ l’effort consenti par l’universite´ Paris Diderot envers le LIAFA. En particulier, le laboratoire a ben´ efici´ e´ de quatre postes de professeurs 16 dont deux ¾ creations´ ¿, et de quatre postes de Maitres de Conference´ 17, dont deux ¾ creations´ ¿. Bien evidemment,´ cet effort est amplement justifie´ par l’enorme´ investissement en enseignement de l’UFR d’Informatique au sein de l’universite´ Paris Diderot.

Politique de recrutement d’enseignants-chercheurs au LIAFA. La politique de recrutement des enseignants-chercheurs au LIAFA est tournee´ quasi-exclusivement vers l’exterieur´ — un seul recrutement interne depuis 2007 sur les 7 postes ouverts au concours a` Paris Diderot pour le LIAFA, avec un candidat exterieur´ classe´ sur chaque premiere` ligne des 7 concours. Notons qu’en cas de non reciprocit´ e´ dans les autres etablissements´ universitaires, cette politique pourrait potentiellement trouver ses limites, ce qui irait a` l’encontre du ﬁl conducteur de la politique de recrutement du LIAFA auquel le laboratoire souhaite se tenir. Le laboratoire est particulierement` sensible a` cette situation, surtout lorsque l’on considere` la pyramide des agesˆ des personnels (voir ﬁgure 1.8). En effet, on peut observer que si les doctorants formes´ au LIAFA et desirant´ poursuivre une carriere` academique´ ont et´ e´ en mesure entre 2007 et 2012 d’obtenir des postes de chercheurs ou d’enseignants-chercheurs dans d’autres universites,´

16. A savoir, un accroissement de deux unites´ du nombre de professeurs entre le 01/01/2007 et le 30/06/2012 : deux recrutements exterieurs´ a` Paris Diderot (François Laroussinie et Vlady Ravelomanana), et une promotion interne a` Paris Diderot (Carole Delporte) — combines´ a` l’arrivee´ de Michel de Rougemont (Pantheon-Assas), au depart´ en retraite de Luc Boasson en octobre 2009, et a` la fin de l’em´ eritat´ de Maurice Nivat ; le recrutement de Sophie Laplante, prenant acte au 01/09/2012 n’apparaˆıt pas sur la figure. 17. A savoir, Aldric Degorre, Constantin Enea, Sylvain Perifel, et Arnaud Sangnier — combines´ au depart´ de Thierry Cachat en disponibilite´ dans l’industrie, a` celui d’Antoine Meyer sur une chaire CNRS a` l’universite´ Paris-Est, a` la promotion de Carole Delporte, et au detachement´ de Dominique Poulalhon au LIX.

13 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE la promotion au titre de professeur des maˆıtres de conferences´ habilites´ et qualiﬁes´ du LIAFA semble s’effectuer avec plus de difﬁculte,´ malgre´ des dossiers de tres` grande qualite.´

18 16 14 12 10 UNIVERSITE 8 CNRS/INRIA 6 ITA 4 2 0 ≤ 30 31-40 41-50 51-60 >60

FIGURE 1.8 – Histogramme des agesˆ des personnels permanents du LIAFA. Parmi les enseignants- chercheurs de plus de 60 ans, trois sont em´ erites.´

1.4 Budget

Le budget du laboratoire depend´ essentiellement de quatre sources de ﬁnancement : les deux tutelles (CNRS et Universite´ Paris Diderot), l’ANR, et l’UE. Les ressources issues des tutelles se repartissent´ en subventions directes et en subventions sur projets. Les subventions directes sont relativement stables depuis 2007 : environ 120Ke par an pour Paris Diderot, et entre 50 et 60Ke par an pour le CNRS, avec une diminution notable en 2012. Les subventions des tutelles sur projet, principalement du CNRS, dependent´ des resultats´ aux appels d’offre PEPS, PICS, LEA, LIA, etc.

CNRS, 60 000 Paris Diderot, 121 400

Europe, 254 001 PEPS, PICS, LEA, Missions, LIA, etc., Salaires, 288 200 169 514 381 185

ANR, 636 221

Fonct., 55 050 Equipement, 58 500

FIGURE 1.9 – Repartition´ des ressources (a` gauche) et des depenses´ (a` droite) 2011 en e

La ﬁgure 1.9 presente´ la repartition´ des ressources (a` gauche) et des depenses´ (a` droite), en 2011, hors salaires des permanents 18. Ces repartitions´ sont typiques des annees´ recentes.´ Environ 50% des ressources du LIAFA proviennent de l’ANR, un petit quart de l’UE au travers principalement des ERC, et un gros quart des tutelles, sous diverses formes (¾ recurrent´ ¿, projets, subventions, etc.). Les depenses´ se repartissent´ principalement en deux gros postes : les salaires (essentiellement des contrats doctoraux

18. Le montant total des ressources excede` le montant des depenses,´ ce qui entraˆıne des report importants. Le laboratoire developpe´ actuellement un effort de reduction´ signiﬁcatif de ses reports, parfois entrave´ par la politique de certains organismes, dont l’ANR, consistant a` notiﬁer tres` tardivement dans l’annee´ le montant de ses subventions.

14 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE ou post-doctoraux) et les missions. Ces dernieres` entrent pour plus d’un tiers des depenses´ du laboratoire ! Cela resulte´ de la tres` grande activite´ de publication des membres du LIAFA dans les congres,` conferences´ et colloques. Ces publications et communications orales sont la cle´ de la diffusion des resultats´ du LIAFA au sein de la communaute,´ et elles sont absolument necessaires´ a` l’acquisition rapide des connaissances les plus en pointe touchant les sujets de recherche du laboratoire.

900 000 1 400 000 800 000 1 200 000 700 000 1 000 000 600 000 Subv. Tutelles Union Européenne 500 000 800 000 PICS, PEPS, LIA, LEA, etc. ANR, ACI, CIFRE, etc. 400 000 ANR, ACI, CIFRE, etc. 600 000 PICS, PEPS, LIA, LEA, etc. 300 000 Union Européenne 400 000 Subv. Tutelles 200 000 200 000 100 000 0 0 2007 2008 2009 2010 2011 2012 2007 2008 2009 2010 2011 2012

FIGURE 1.10 – Ressources en e (hors salaires des permanents) de 2007 a` 2012

Les figures 1.10 et 1.11 presentent´ respectivement l’evolution´ des ressources et des depenses´ du laboratoire de 2007 a` 2012. On peut noter la constante et importante proportion des projets ANR dans le budget. Les projets ANR portes´ par le laboratoire, ou impliquant certains de ses membres, relevent` de differents´ programmes (SYSCOMM, CHIST-ERA, DEFIS, Sesur, SETIN, ARA-SSIA, ARPEGE, SEGI, VERSO, Tel´ ecom,´ Securit´ e,´ COSINUS, etc.). Toutefois, les programmes ¾ Blancs ¿ et ¾ JCJC ¿ demeurent les deux principales sources de financement du laboratoire aupres` de l’ANR. On note l’ap- parition de financements europeens´ a` partir de 2010, principalement liee´ a` une ERC et a` l’arrivee´ de l’equipe´ Algorithmes et Complexite´ d’Orsay 19.

450 000 900 000 400 000 800 000 350 000 700 000 300 000 600 000 Missions Salaires 250 000 500 000 Fonconnement Equipement 200 000 400 000 Equipement Fonconnement 150 000 300 000 Salaires Missions 100 000 200 000 50 000 100 000 0 0 2007 2008 2009 2010 2011 2007 2008 2009 2010 2011

FIGURE 1.11 – Depenses´ en e (hors salaires des permanents) de 2007 a` 2011

Utilisation des subventions des tutelles. Comme indique´ ci-dessus, les subventions des tutelles s’el´ event` a` environ 170Ke, a` savoir environ 120Ke de l’universite´ Paris Diderot plus environ 50Ke du CNRS. Le laboratoire n’impose pas ses equipes´ sur leurs contrats, et ces 170Ke forment donc l’unique ressource pour le fonctionnement du laboratoire proprement dit. Ce budget est evidemment´ utilise´ pour couvrir toutes les depenses´ relevant du fonctionnement global du laboratoire : fournitures, achats de serveurs, achats de terminaux legers,´ photocopies, etc. Une partie importante du budget du laboratoire

19. L’arrivee´ de cette equipe´ ne s’est pas traduite en un accroissement des projets ANR car les projets ANR en cours de l’equipe´ sont restes´ ger´ es´ a` l’universite´ Paris Sud.

15 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE est toutefois egalement´ utilisee´ pour subvenir aux besoins des membres du LIAFA ne disposant pas de ressources propres, ou ne pouvant pas abonder aux ressources propres de leurs equipes.´ Ainsi, une partie non negligeable´ du budget est utilisee´ pour l’achat d’ordinateurs (apres` avis de la commission ¾ materiel´ ¿) et pour couvrir des missions. Si la demande de mission, de materiel´ ou egalement´ de financement de stage, est justifiee´ (c’est-a-dire` : (1) ne peut-etreˆ financee´ par l’equipe,´ et (2) offre un important inter´ etˆ scientifique), alors elle est gen´ eralement´ acceptee´ par la direction. Ce mode de fonctionnement permet de lisser les chocs lies´ a` des absences ponctuelles de ressources propres au sein d’une equipe,´ ou d’un sous-groupe au sein d’une equipe.´

1.5 Le LIAFA dans son environnement

1.5.1 L’universite´ Paris Diderot, l’UFR, la Fed´ eration,´ et l’Ecole Doctorale

Le laboratoire entretient des relations tres` etroites´ avec l’UFR d’Informatique de Paris Diderot. Son conseil scientifique est actuellement presid´ e´ par Olivier Carton (Pr Paris Diderot), membre du LIAFA. Le directeur ou la directrice et son adjoint(e) sont membres de droit de ce conseil. Le directeur de l’UFR depuis mi-2012, François Laroussinie, est egalement´ membre du LIAFA (l’ancien directeur, Jean-Marie Rifflet, etait´ membre de PPS). Le laboratoire est egalement´ tres` fortement implique´ dans l’Ecole Doctorale Sciences mathematiques´ de Paris Centre (ED 386), dont Ahmed Bouajjani, membre du LIAFA, assure la responsabilite´ pour l’informatique a` Paris Diderot 20. L’ED joue un roleˆ important pour l’informatique a` Paris Diderot puisque qu’elle permet aux laboratoires PPS et LIAFA d’obtenir environ cinq allocations doctorales par an. L’arbitrage entre les candidatures en informatique a` Paris Diderot est effectue´ par une commission ad hoc formee´ du responsable pour l’informatique a` Paris Diderot de l’ED et des deux directeurs des laboratoires LIAFA et PPS 21, le classement final revenant au conseil de l’ED. Le laboratoire est membre de la Fed´ eration´ de Recherche en Mathematiques´ de Paris Centre (FR 2830). Cette Fed´ eration´ est rattachee´ a` l’INSMI. Elle regroupe les cinq laboratoires de mathematiques´ et d’informatique associes´ au CNRS actuellement presents´ sur les sites de Jussieu et de Chevaleret, et relevant conjointement des universites´ Pierre et Marie Curie et Paris Diderot ou de l’une ou l’autre de ces universites.´ Elle a principalement pour roleˆ de coordonner ces cinq laboratoires pour permettre une meilleure gestion des moyens communs, dont en particulier de la Bibliotheque` de Mathematiques-Informatique´ Recherche, rattachee´ aux deux universites´ Pierreet Marie Curie et Paris Diderot. Jean Mairesse, membre du LIAFA, est directeur adjoint de la Fed´ eration.´ Enfin, la presence´ d’Hugues Fauconnier (MdC Paris Diderot), membre du LIAFA, au Conseil d’Admi- nistration de l’Universite´ Paris Diderot, illustre le volonte´ du laboratoire de s’investir dans les structures de l’universite.´

1.5.2 La Fondation et le LABEX Sciences Mathematiques´ de Paris

Le LIAFA ben´ eﬁcie´ du cadre scientiﬁque offert par la Fondation Sciences Mathematiques´ de Paris (SMP) 22. Il s’agit d’un reseau´ de laboratoires, initialement structure´ en RTRA, fonde´ en 2006 par des universites´ et institutions de recherche parisiennes, fed´ erant´ 11 laboratoires de mathematiques´ et d’informatique, ainsi que 20 equipes-projets´ de l’INRIA. La fondation SMP reunit´ ainsi plus de 1200 chercheurs. Ce reseau´ couvre ainsi l’ensemble du spectre des mathematiques´ pures et appliquees,´ ainsi

20. L’etablissement´ principal de rattachement de l’ED est l’universite´ Pierre et Marie Curie (P6), avec, en tant qu’etablissements´ co-accredit´ es,´ l’universite´ Paris Diderot (P7) et l’ENS Paris. Les autres etablissements´ associes´ a` l’ED sont les universites´ Pantheon-Sorbonne´ (P1) et Paris Descartes (P5), ainsi que l’INRIA. 21. Ce mode de fonctionnement ne donne pas entiere` satisfaction, et cette procedure´ de classement entre les candidats en informatique, herit´ ee´ d’une epoque´ ou` les laboratoires etaient´ de plus petite taille, devrait etreˆ revue l’an prochain. 22. Valerie´ Berthe´ (LIAFA) est directrice adjointe de cette fondation.

16 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE que de l’informatique fondamentale. La Fondation initie et ﬁnance des programmes d’envergure internationale (bourses de master, chaires d’excellence, positions post-doctorales, invitations de chercheurs, programmes internationaux, etc.). Elle a pour mission de favoriser et de coordonner les echanges´ entre ses laboratoires, les ouvertures vers les autres disciplines scientiﬁques, ainsi que de favoriser les collaborations entre les chercheurs et le monde economique´ et industriel. La fondation est egalement´ adossee´ a` la Fed´ eration´ de Recherches en Mathematiques´ (FR2830 du CNRS) 23. La fondation SMP a porte´ le LABEX Sciences Mathematiques´ de Paris qui a obtenu ce statut en 2011. Ce LABEX, qui couvre les laboratoires et equipes´ de la fondation SMP, travaille en concertation avec les deux autres LABEX parisiens en mathematiques,´ a` savoir, le LABEX Bezout,´ a` l’interface entre mathematiques´ et informatique, et le LABEX Mathematiques´ Hadamard, plus centree´ sur les mathematiques.´ Ce contexte parisien particulierement` stimulant offre donc des possibilites´ de collaborations fructueuses et variees´ au sein de l’informatique fondamentale (entre UMR CNRS, et avec les equipes-projets´ INRIA associees),´ mais egalement´ a` l’interface mathematiques-informatique´ a` l’echelle´ parisienne.

1.5.3 Inria, CEA et Technicolor

Le LIAFA heberge´ l’equipe-projet´ INRIA ¾ GANG ¿. Ce projet, sous la responsabilite´ de Laurent Vien- not (DR INRIA), membre du LIAFA, inclut les membres de l’equipe´ Algorithmique distribuee´ et graphes dont les domaines de competence´ sont en rapport avec la conception d’algorithmes pour les reseaux´ a` grande echelle,´ en utilisant les propriet´ es´ structurelles de ces reseaux´ 24. Le laboratoire entretient egalement´ des liens etroits´ avec le CEA, comme en temoigne´ par exemple le presence´ pendant un an dans l’equipe´ Combinatoire de Jer´ emie´ Bouttier, chercheur CEA en physique statistique combinatoire. Enﬁn, il convient de souligner que le LIAFA a entretenu durant ces dernieres` annees´ des liens forts avec Technicolor (publications communes, projet ANR ¾ PROSE ¿, etc.).

1.5.4 Environnement scientiﬁque

1.5.4.1 Local et regional´

Notre partenaire local privilegi´ e´ est bien surˆ le laboratoire PPS (voir section 1.1.2). Les liens entre le LIAFA et PPS ne devraient que pouvoir se renforcer a` l’avenir (voir section 2.3). Le LIAFA entretient toutefois egalement´ des liens etroits´ avec d’autres partenaires a` Chevaleret, en particulier avec l’equipe´ Logique mathematique´ de l’IMJ sur la complexite´ algebrique´ (un article a` STOC 2012 [DMPY12]) et la veriﬁcation´ approchee´ de systemes` probabilistes (ANR VERAP), ainsi qu’avec l’equipe´ Algebres` d’operateurs´ de l’IMJ sur les groupes et semi-groupes d’automates (projet BQR inter-disciplinaire 2010- 1011 Paris Diderot entre le LIAFA et l’ IMJ). Au niveau de l’informatique de Paris Centre, de forts liens se mettent en place avec le Departement´ d’Informatique (DI) de l’ENS, en particulier avec l’equipe´ de cryptographie ¾ Cascade ¿, et par l’arrivee´ recente´ de Claire Mathieu. Notons que la Fondation SMP permet de travailler en etroite´ synergie avec les trois laboratoires Informatiques de la Fondation, a` savoir le LIAFA, le LIENS et PPS. Par ailleurs, les liens entre le LIAFA et Tel´ ecom´ Paris-Tech jusque-la` principalement orientes´ autour des automates se renforcent egalement´ autour du quantique (securit´ e´ et communications quantiques). Les liens avec le LIP6 sont egalement´ multiples et relevent` de thematiques´ variees,´ dont la combinatoire (en particulier avec la mise en place du seminaire´ de combinatoire ¾ Philippe Flajolet ¿ a` l’IHP), le calcul ¾ on-line ¿

23. Jean Mairesse (LIAFA) est directeur adjoint de cette fed´ eration.´ 24. Membres : Yacine Boufkhad (MdC, Paris Diderot), Pierre Charbit (MdC, Paris Diderot), Carole Delporte (Pr., Paris Diderot), Hugues Fauconnier (MdC, Paris Diderot), Dominique Fortin (CR INRIA, non membre du LIAFA), Pierre Fraigniaud (DR CNRS), Michel Habib (Pr., Paris Diderot), Amos Korman (CR CNRS), Fabien Mathieu (chercheur CDD, INRIA), Fabien de Montgolﬁer (MdC, Paris Diderot), et Laurent Viennot (DR INRIA, responsable du projet).

17 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE

(ANR NeTOC), les protocoles distribues´ pour les reseaux´ (ANR SHAMAN), etc. Plus largement, en Ile-de-France, le LIAFA collabore activement avec les principaux laboratoires en informatique de la region,´ dont en particulier le LIGM (combinatoire algebrique,´ automates et systemes` dynamiques, verification´ et systemes` infinis, 3 theses` en codirection plus deux projets ANR : AMIS et EQUINOCS), le LIPN (combinatoire), le LIX (combinatoire, algorithmique distribuee),´ le LRI (tolerance´ aux pannes, protocoles distribues´ pour les reseaux),´ et le LSV (jeux, logiques temporelles, verification,´ quatre projets ANR : AVERILES, AVERISS, DOTS et ImpRo), le LACL (logique et automates, specification´ et verification,´ 1 these` en codirection et projet ANR EQUINOCS), et caetera.

1.5.4.2 National

Au niveau national, le LIAFA entretient des liens etroits´ avec les principaux laboratoires franc¸ais ayant une composante informatique fondamentale. Ainsi, outre des collaborations individuelles ponctuelles, le laboratoire collabore activement, voire formellement au travers de projets scientiﬁques communs, avec evidemment´ le LaBRI (entre autres sur la combinatoire, l’algorithmique distribuee´ pour les reseaux,´ la tolerance´ aux pannes, la logique, les automates et les jeux), mais aussi avec l’IRISA, dont les membres de l’equipe-projet´ ASAP de l’INRIA Bretagne (calcul distribue,´ ANR DISPLEXITY), avec VERIMAG (ANR AMAES, AVERILES, VERIDYC, EQINOCS), avec l’IRCCyN (ANR DOTS, ImPro), et avec le LIRMM (complexite,´ algorithmes de graphes).

1.5.4.3 International

Il serait vain de lister les collaborateurs internationaux des membres du LIAFA, et consulter les listes de publications des equipes´ sufﬁra a` evaluer´ le volume de ces collaborations nombreuses et fructueuses. Quelques-unes des collaborations formelles que le LIAFA entretient avec des organismes etranger´ sont listees´ ci-dessous :

• Participation au projet STREP ¾ EULER ¿ : Experimental UpdateLess Evolutive Routing. • Participation au projet STREP ¾ QCS ¿ : Quantum Computer Science. • Participation au EU Integrated Project IST-2003-015848 ¾ QAP ¿ : Qubit Applications (quantum information processing). • Direction de l’ESF Research networking programme ¾ AutoMathA ¿ : Automata : from Mathe- matics to Applications. • Participation au projet CHIST-ERA 25 ¾ DIQIP ¿ : Device-Independent Quantum Information Processing. • Responsabilite´ du projet PICS Franco-Suisse ¾ Architectures multicœurs et algorithmique distribuee´ ¿. • Nombreuses responsabilites´ de projets bilateraux´ du Ministere` des Affaires Etrangeres` (voir rapports des equipes).´ En outre, le LIAFA porte deux laboratoires europeens´ associes´ du CNRS, a` savoir, un LEA avec Israel¨ (French-Israeli Laboratory on Foundations of Computer Science (FILOFOCS), codirige´ par l’universite´ de Tel-Aviv University), et un LEA avec la Republique´ Tcheque` (STRUCO, codirige´ avec l’Universite´ Charles-Prague). Le Laboratoire participe de plus activement au LIA ¾ LIRCO ¿ (Laboratoire Interna- tional Franco-Queb´ ecois´ de Recherche en Combinatoire), au LIA ¾ FSQL ¿ (France-Singapore Quan- tum Physics and Information Lab), au LIA ¾ INFINIS ¿ avec l’Argentine (Informatique Fondamentale, Logique, Langages, Veriﬁcation´ et Systemes),` au LIA ¾ INFORMEL ¿ avec l’Inde (responsables LSV- CMI), et enﬁn a` l’UMI Franco-Japonaise ¾ FFLI ¿ (French Laboratory for Informatics).

25. Activite´ de cooperation´ des agences nationales de moyens sous l’egide´ de l’ERA-Net de l’Union Europeenne´ (coordonne´ par l’ANR pour la France).

18 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE

1.5.5 Animation

1.5.5.1 Nationale

Le LIAFA est fortement implique´ dans la vie et l’animation des GdR, principalement au niveau du GdR Informatique Mathematique´ (IM) dont il assure la responsabilie´ de trois groupes de travail et d’un pole,ˆ en sus de la participation au comite´ de direction. Le LIAFA est egalement´ fortement implique´ dans les GdR Information Quantique, Fondements & Applications (IQFA) (responsabilite´ de l’axe Communica- tion quantique), Architecture, Systemes,` Reseaux´ (ASR) (participation au conseil scientiﬁque du poleˆ ResCom), et Calcul (participation au conseil scientiﬁque) – ce dernier GdR relevant de l’INSMI. Le LIAFA est egalement´ frequemment´ implique´ dans des missions classiques d’expertise au niveau national : jury AERES, comite´ ANR, jurys PES/PEDR, etc.

1.5.5.2 Internationale

Le LIAFA participe activement a` l’animation de la recherche internationale, en particulier au travers de la participation de ses membres a` de nombreux comites´ editoriaux´ de revues internationales, et a` de nombreux comites´ de programme et/ou de pilotage de conferences´ :

Comites´ editoriaux´ de revues internationales : International Journal of Quantum Information, ACM Transactions on Computation Theory, Distributed Computing, Theory of Computing Systems, Fundamenta Informaticae, ICST Transactions on Algorithms Engineering, Journal of Intercon- nection Networks, Mathematica Bohemica, Annals of Combinatorics, RAIRO Theoretical Infor- matics and Applications 26, Annals of Applied Probability, International Journal of Algebra and Computation, Queueing Systems, The Houston Journal of Mathematics, Semigroup Forum, Ma- thematical Structures in Computer Science, Techniques et Sciences Informatiques, Formal Me- thods in System Design, etc. Comites´ de programme et/ou de pilotage de conferences´ : STOC, ICALP, SODA, PODC, POPL, LICS, STACS, DISC, CONCUR, SPAA, WG, MFCS, FCT, QIP, CAV, FPSAC, SOFSEM, AofA, DLT, CCR, TACAS, FSTTCS, FOSSACS, FORMATS, VMCAI, etc.

Enﬁn, le LIAFA est frequemment´ implique´ dans des missions classiques d’expertise internationale, comme par exemple la participation au panel d’experts du programme FET (Future and Emerging Technologies)-OPEN en ICT (Information and Communication Technologies), ou la participation aux jurys de programmes ERC.

1.5.6 Interdisciplinarite´

En termes d’interdisciplinarite,´ les forces du laboratoire sont tres` largement mobiliseees´ autour de l’interaction entre informatique et mathematiques.´ Des chercheurs du laboratoire se sont ainsi fortement investis dans les structures locales et nationales d’animation autour de cette interface : deux charges´ de mission CNRS en charge de l’interface entre Informatique et Mathematiques´ 27, responsabilites´ de GT et de poleˆ au sein du GdR Informatique Mathematique,´ vice-direction Fondation SMP et Fed´ eration´ FRMPC, organisation d’un trimestre 28 et d’un seminaire´ recurrent´ 29 a` l’IHP, etc. Notons de plus qu’un membre du LIAFA 30 est issu de la section 01 (actuellement 41).

26. Christian Choffrut et Olivier Serre sont memeˆ co-editeurs´ en chef de la revue. 27. Valerie´ Berthe,´ puis Jean Mairesse. 28. Trimestre ¾ Metric ¿ en 2011. 29. Seminaire´ de Combinatoire Philippe Flajolet. 30. Jeremy Lovejoy.

19 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE

Les resultats´ obtenus a` cette interface relevent` principalement de l’informatique mathematique,´ les problematiques´ et motivations provenant de l’informatique, les outils et les methodes´ de resolution´ etant´ de nature mathematique.´ Inversement, les travaux effectues´ au sein du laboratoire peuvent avoir des re- tombees´ directes en mathematiques´ (theorie´ des nombres et arithmetique,´ par exemple) avec un usage d’outils relevant des mathematiques´ discretes` et de l’informatique theorique.´ Parmi les themes` developp´ es´ a` cette interface au laboratoire, citons en particulier la combinatoire (combinatoire enum´ erative´ et algebrique,´ analyse d’algorithmes, cartes planaires, etc.), l’etude´ des automates (aspects algebriques´ et topologiques), ou encore, l’etude´ des systemes` dynamiques discrets. Les outils mathematiques´ les plus largement utilises´ relevent` des probabilites,´ de la logique, de l’algebre` et de la topologie, de la theorie´ ergodique ou encore de la theorie´ des nombres et de l’arithmetique.´ Outre les mathematiques,´ plusieurs autres axes interdisciplinaires emergent,´ en direction :

• de la biologie autour de la bio-informatique (reseaux´ phylogen´ etiques´ et graphes cordaux, algorithmes de graphes pour l’etude´ de l’evolution´ des genomes´ de virus, sequenc¸age´ ¾ haut debit´ ¿, etc.), dans le cadre d’un projet ANR ¾ COSINUS ¿. • des SHS autour de problematiques´ liees´ aux reseaux´ sociaux (modelisation´ et algorithmique des reseaux´ sociaux), dans le cadre de deux PEPS et de deux projets ANR. • de la physique autour de thematiques´ liees´ au quantique (journees´ ¾ Quantum in Paris ¿, GdR In- formation Quantique, Fondements & Applications (IFQA), BQR Calcul distribue´ quantique, etc.), et a` la combinatoire (en collaboration avec le CEA) via la physique statistique et combinatoire.

1.6 Formation par la recherche

Le LIAFA porte une attention toute particuliere` a` la formation par la recherche, en accueillant un grand nombre de stagiaires de M2 et, comme mentionne´ prec´ edemment,´ en produisant un effort pour augmenter son nombre de doctorants. Le laboratoire est implique´ dans plusieurs masters et filieres` d’enseignement de la region´ parisienne, bien surˆ a` Paris Diderot, mais aussi a` l’Ecole Polytechnique, a` l’Ecole Centrale, etc. Le LIAFA est extremementˆ implique´ dans le MPRI 31. De fait, la majorite´ des doctorants du laboratoire sont issus du MPRI. Neanmoins,´ le laboratoire participe egalement´ activement a` plusieurs filieres` professionnalisantes dont celle de la specialit´ e´ IAP du master Informatique de Paris Diderot. En- fin, le LIAFA s’implique reguli´ erement` dans l’organisation d’ecoles´ thematiques,´ comme par exemple les ecoles´ ¾ jeunes chercheurs en informatique mathematique´ ¿ et l’ecole´ de printemps en informatique theorique.´ Par ailleurs, le laboratoire a le souci de maintenir son effort de formation aupres` des doctorants, tout au long de leur these.` Ces etudiants´ sont evidemment´ invites´ a` suivre les nombreux seminaires´ hebdomadaire d’equipes´ mentionnes´ prec´ edemment,´ mais, surtout, le LIAFA, en partenariat avec PPS, prend soin de maintenir un seminaire´ dedi´ e´ aux doctorants, afin que ceux-ci puissent sensibiliser l’ensemble des etudiants´ du laboratoire a` leur sujet de recherche. Le laboratoire a recemment´ mis en place un protocole d’accueil et de suivi des doctorants, incluant en particulier la commission ¾ doctorants ¿ mentionnee´ en section 1.2.2, la journee´ des entrants decrite´ en section 1.2.3, et une evaluation´ a` mi-parcours etablie´ sous la responsabilite´ de l’Ecole Doctorale. Notons, plus gen´ eralement,´ que le LIAFA s’est egalement´ implique´ dans l’enseignement aupres` des professeurs du secondaire dans le cadre de la formation au futur enseignement ISN (Informatique et Sciences du Numerique).´

31. Master Parisien de recherche en Informatique, cohabilite´ par l’universite´ Paris Diderot, l’ENS Paris, l’ENS Cachan, l’ecole´ Polytechnique, en partenariat avec les universites´ Pierre et Marie Curie et Paris Sud, et Telecom ParisTech.

20 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE

1.7 Vulgarisation et diffusion scientiﬁques

Les membres du laboratoire sont fortement impliques´ dans la diffusion des connaissance sous des formes variees´ :

• Redaction´ d’articles dans les revues et journaux de vulgarisation : La Recherche, Le Monde supplement´ Sciences & Techno, Sciences & Avenir, etc. • Redaction´ d’articles pour des sites dedi´ es´ comme Images des Mathematiques´ ou Interstices, dont Laurent Viennot (LIAFA) est editeur´ scientiﬁque. • Interventions publiques : Feteˆ de la Science, Cite´ des Sciences et de l’Industrie, College` Belgique, etc. • Exposes´ dans les colleges` et lycees,´ et preparation´ aux Olympiades internationales de mathematiques.´ • Expositions : projet ¾ Quantum design-Anabole ¿, projet ¾ Encuentra el inﬁnito ¿ au musee´ des sciences de Santiago du Chili, etc.

Notons en particulier que deux doctorants du LIAFA, Irene` Markovici et Antoine Taveneaux, sont membres du comite´ d’organisation du seminaire´ Mathematic Park, Antoine Taveneaux etant´ de plus membre du bureau de MATh.en.JEANS. Enfin, la cel´ ebration´ de l’annee´ Alan Turing 2012 a et´ e´ l’occasion de nombreuses interventions (expose´ lors des journees´ de l’ENS Lyon, etc.). Jean Mairesse a ainsi et´ e´ conseiller scientifique du film ¾ Le modele` Turing ¿ produit par CNRS Images, et a participe´ au Festival du Film de chercheurs 2012. 1.8 Valorisation

Les activites´ de valorisation menees´ au sein du laboratoire sont principalement orientees´ vers des entreprises de type ¾ startup ¿. On peut ainsi citer plus specifiquement´ : • la participation a` la creation´ de la startup Move&Play 32 sur le partage de donnees´ personnelles, • une cooperation´ et mission d’expertise avec Ligaran consacree´ a` la publication sur supports demat´ erialis´ es,´ • une collaboration autour du calcul quantique et de la distribution quantique de cles,´ avec la societ´ e´ IDQuantique, entreprise basee´ a` Geneve` qui propose des solutions de chiffrement reseau´ haute performance. Notons egalement´ un dep´ otˆ de brevet en 2008 : ¾ Utilisation d’un ensemble de clients privilegi´ es´ pour une diffusion collaborative de contenu ¿. Il convient enfin de mentionner la these` Cifre de Stephane´ Raux effectuee´ sous la direction de Chris- tophe Prieur au sein de l’entreprise innovante Linkfluence. Cette these` porte sur la mise en place d’une infrastructure d’analyse de Twitter. Dans ce cadre, Stephane´ Raux, en collaboration avec Alexis Jacomy, Ronan Quidu, et Nils Grunwald,¨ a remporte´ le concours Google de Data Viz - Elections 2012, avec l’application web MediArena. Cette application propose a` l’utilisateur de comparer le traitement reserv´ e´ par 12 medias´ en ligne aux thematiques´ et aux candidats de l’election´ presidentielle´ française 2012.

32. Maintenant CleverScale.

21 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE

1.9 Annexes

1.9.1 Liste des membres permanents chercheurs et enseignants-chercheurs au 10/09/2012 Les noms soulignes´ sont ceux des responsables d’equipe.´ – Equipe Algorithmes et complexite´ 1. Michel De Rougemont (Pr, Pantheon-Assas) 2. Iordanis Kerenidis (CR CNRS, HDR) 3. Sophie Laplante (Pr, Paris Diderot) 4. Fred´ eric´ Magniez (DR CNRS) 5. Adi Rosen´ (DR CNRS) 6. Miklos Santha (DR CNRS) 7. David Xiao (CR CNRS) – Equipe Algorithmique distribuee´ et graphes 1. Yacine Boufkhad (MdC, Paris Diderot) 2. Pierre Charbit (MdC, Paris Diderot) 3. Fabien de Montgolﬁer (MdC, Paris Diderot) 4. Carole Delporte (Pr, Paris Diderot) 5. Hugues Fauconnier (MdC, Paris Diderot, HDR) 6. Pierre Fraigniaud (DR CNRS) 7. Michel Habib (Pr, Paris Diderot) 8. Amos Korman (CR CNRS) 9. Fabien Mathieu (Chercheur INRIA, HDR) 10. Christophe Prieur (MdC, Paris Diderot, HDR prevue´ automne 2012) 11. Mathieu Rafﬁnot (CR CNRS, HDR) 12. Nicolas Schabanel (DR CNRS) 13. Jean-Sebastien Sereni (CR CNRS) 14. Laurent Viennot (DR INRIA) Note : Jean-Sebastien Sereni, CR CNRS actuellement au LIAFA, devrait prochainement rejoindre le LORIA suite a` sa demande de mutation pour rapprochement de conjoints. Fabien Mathieu (Chercheur INRIA) est egalement´ membre de l’equipe,´ pour toute la duree´ de son CDD de trois ans a` l’INRIA.

– Equipe Automates et applications 1. Valerie´ Berthe´ (DR CNRS) 2. Laurent Bienvenu (CR CNRS) 3. Olivier Carton (Pr, Paris Diderot) 4. Christian Choffrut (Pr, Paris Diderot) 5. Thomas Colcombet (CR CNRS, HDR prevue´ automne 2012) 6. Marie Ferbus (MdC, Paris Diderot) 7. Christiane Frougny (Pr em´ erite,´ Paris Vincennes-Saint-Denis) 8. Mai Gehrke (DR CNRS)

22 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE

9. Serge Grigorieff (Pr em´ erite,´ Paris Diderot) 10. Łukasz Kaiser (CR CNRS) 11. Ines Klimann (MdC, Paris Diderot) 12. Jean Mairesse (DR CNRS) 13. Sylvain Perifel (MdC, Paris Diderot) 14. Matthieu Picantin (MdC, Paris Diderot) 15. Jean Eric Pin (DR CNRS) 16. Olivier Serre (CR CNRS) 17. Wolfgang Steiner (CR CNRS) 18. Jean-Baptiste Yunes` (MdC, Paris Diderot, HDR) 19. Wieslaw Zielonka (Pr, Paris Diderot) – Equipe Combinatoire 1. Guillaume Chapuy (CR CNRS) 2. Sylvie Corteel (DR CNRS) 3. Enrica Duchi (MdC, Paris Diderot) 4. Jeremy Lovejoy (CR CNRS) 5. Roberto Mantaci (MdC, Paris Diderot, HDR) 6. Anne Micheli (MdC, Paris Diderot) 7. Vlady Ravelomanana (Pr, Paris Diderot) Note : Dominique Poulalhon (MdC, Paris Diderot), actuellement en detachement´ au LIX, devrait rejoindre le laboratoire a` la rentree´ 2013.

– Equipe Modelisation´ et verification´ 1. Eugene` Asarin (Pr, Paris Diderot) 2. Ahmed Bouajjani (Pr, Paris Diderot) 3. Aldric Degorre (MdC, Paris Diderot) 4. Constantin Enea (MdC, Paris Diderot) 5. Irene Guessarian (Pr em´ erite,´ Pierre et Marie Curie) 6. Peter Habermehl (MdC, Paris Diderot, HDR) 7. Florian Horn (CR CNRS) 8. Yan Jurski (MdC, Paris Diderot) 9. François Laroussinie (Pr, Paris Diderot) 10. Arnaud Sangnier (MdC, Paris Diderot) 11. Mihaela Sighireanu (MdC, Paris Diderot) 12. Tayssir Touili (CR CNRS, HDR) Note : Yan Jurski (MdC, Paris Diderot) ne devrait plus en l’etat´ faire partie du laboratoire au 31/12/2013. Il pourrait toutefois reint´ egrer´ le laboratoire au 01/01/2014 s’il en fait explicitement la demande fin 2013, demande qui sera alors etudi´ ee´ par le conseil de laboratoire.

23 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE

1.9.2 Liste des membres du conseil de laboratoire

Membres de droit (2 sieges)` – Directeur du laboratoire : Pierre Fraigniaud (DR CNRS) – Directrice adjointe du laboratoire : Valerie´ Berthe´ (DR CNRS) College` enseignant-chercheur et chercheur de categorie´ A (5 sieges)` – Eugene Asarin (Pr, Paris Diderot) – Olivier Carton (Pr, Paris Diderot) – Vlady Ravelomanana (Pr, Paris Diderot) – Michel de Rougemont (Pr, Pantheon-Assas) – Nicolas Schabanel (DR CNRS) College` enseignant-chercheur et chercheur de categorie´ B (5 sieges)` – Enrica Duchi (MdC, Paris Diderot) – Fabien de Montgolﬁer (MdC, Paris Diderot) – Mihaela Sighireanu (MdC, Paris Diderot) – David Xiao (CR CNRS) – Jean-Baptiste Yunes` (MdC, Paris Diderot) College` secretariat,´ ingenieur´ et technicien (2 sieges)` – Laifa Ahmadi (IR, CNRS) – Noelle¨ Delgado (AI, CNRS) College` Doctorants (1 siege)` – Adeline Pierrot

24 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE

1.9.3R eglement` interieur´

25 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE

26 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE

1.9.4 Charte d’utilisation des moyens informatiques décrite par la RFC 1855 dont une gurent doitdansungurent informée tel être fichier ulier via le courrier électronique où chacun stations de travail individuelles sont tenus d'introduire sans autorisation des personnes contenant du matériel informatique en libre Netiquette de de l'existence d'un droit d'accès et des modalités 2 http://ww.ccr.jussieu.fr/ccr/Netiquette.html de les administrer selon les règles définies par les ASR. lespar selonrègles définies lesadministrerles de sans utilisateursexplicite. autorisation d'autres fichiers tiers. laboratoire. du au interne fonctionnement relative et informatiques ressources les dans tout échange de communication en partic du sonau nom s'ils'exprime laboratoire. nom en ou préciser doit etc.) imprimantes, disque, espace calcul, de bloquer des ressources compte son personnel. sur courrier son transférer avec de multiples sessions interactives inutilisées et de extérieures au laboratoire dans les sallesservice. sont administrateurs lespermises. par faites sauvegarde de copies desASR. autorisation formalités préalables à sa libertés des (CNIL). et l'Informatique mise en oeuvre auprès de la Commission de l'existence de ce fichier, de sa Nationale finalité, de concernant. collecte la d'informations celui-ci, la dès de miseen oeuvre de site estsur le français en traduction –Les possesseurs d'ordinateurs portables ou de ou portables d'ordinateurs possesseurs –Les confidentialité de Règles 4- – Les utilisateurs ne doivent pas tenter de lire, de copier, de divulguer ou de– modifier les Les utilisateurs doivent s'interdire toute tentative d'interception de communications entre – Les utilisateurs sont tenus à la réserve d'usage sur toute information obtenue en utilisant 5-bon usage de Règles – Tout utilisateur a le droit de travailler sans être dérangé. La courtoisie doit être de mise – Les utilisateurs sont invités à un usage raisonnable des moyens communs (puissance de – Il est recommandé d'exécuter les travaux longs et non interactifs en tâche de fond, d'éviter – réseau. du autres utilisateurs lespaspénalisent ses applications ne doit que On s'assurer – On doit s'abstenir de fumer, de manger et intellectuelle de propriété la Respect 6- – Il est interdit à tout utilisateur de faire des copies de logiciels– commerciaux. Seules les Il est interdit d'installer des logiciels commerciaux sur les serveurs du laboratoire sans 1992) 22 libertés du juillet et92-684 (loi Informatique 7- – La création de tout fichier contenant des informations nominatives doit faire l'objet de –sur filaquelle informationsdes personne Toute 8- Usage des servicesInternet - Il est fortement recommandé de lire la pour des nécessités oyens informatiques ple des informations sur la messagerie, les fonctionnement des m traces sont consultées par les ASR pour des l'utilisation des ressources matérielles ou x dysfonctionnements des services. Toutefois, olation ou soupçon de violation des systèmes 1 des programmes mettant volontairement en cause directeur du directeur laboratoire. législation en la vigueur. laboratoire. du informatiques laboratoire. du des systèmes. Ces fichiers conservent par exem dates de connexions locales et à distance. Ces besoins de statistiques ou pour remédier au d'une peuvent mis judiciaire, cesle dans procédure être cadre fichiers à la dispositionla de justice. de maintenance et de logicielles ainsi que gestionles échanges via le réseau peuvent être analysés et technique, contrôlés dans le respect de la législation applicable etlibertés. notamment de la loi sur l'informatique et les ASR. fichiers. ses propres sur ASR. au aux préalable référé avoir sans tout ou support, autre de l'Internet informatiques. systèmes l'intégrité des aux signalé être ASR. laboratoire doit du informatiques Charte d'utilisation des moyens informatiques du LIAFA LIAFA du informatiques moyens des d'utilisation Charte -L' ASR est responsable techniquement du bon du techniquement Cette charte définit les tous. s'impose ElleLIAFA. à du informatiques règles d'accès et d'utilisation locale ou à distance d'accès Conditions1- des moyens responsable – L'accès aux ressources informatiques du LIAFA est soumis à autorisation– préalable du incessible. et personnelle strictement est d'accès L'autorisation –est autorisation Cette est délivrée despour activités à la missionconformes du et laboratoire à (ASR) Réseau Systèmes et Administrateur et Utilisateur 2- ASR - l'utilisateur est tout enseignant, chercheur, -L' invité ou personnel utilisant les systèmes -réseau. et machines des du la sécurité d'assurer la charge a Il -des utilisés génèrent services L'ensemble fichiersdes traces essentiels de à l'administration - Extrait de la charte utilisateur de resources informatiques du CNRS : sécuritéRègles 3- de – Les utilisateurs doivent choisir des mots de passe –respectant les recommandations des Tout utilisateur est responsable des conséquences des autorisations qu'il donne aux autres – soncompte utilisercompte doit nid'autrui. utilisateur le ne prêter Aucun – L'utilisateur ne doit pas installer de– logiciels sur les Il est interdit d'utiliserserveurs, ou de développer qu'ils proviennent de – Tout constat de violation, tentative de vi –ASR. lespar instaurés de sécurité contourner mécanismes les de interdit est Il d'essayer

27 CHAPITRE 1. RAPPORT SCIENTIFIQUE DU LABORATOIRE s (courrier, forums, pages web, etc.) et des utilisateurs du laboratoire et m'engage à tique, (article 323-1 à 323-7 du Code pénal),(cf. 3 des pages personnelles des chercheurs doivent se Paris, le le Paris, lu approuvé) manuscrite :la et mention de (précédée Signature interlocuteurs dans les échanges électronique s'imposer le respect des lois diffamatoire. pornographique, raciste, injurieux, notamment celles relatives aux publications à caractère imprudence. parloisles violer on car de risque précaution grande plus avec la faire ) http://www.legifrance.gouv.fr/citoyen/code.cgi ) http://www.culture.fr/culture/dglf/ ) http://www.telecom.gouv.fr/francais/activ/techno/crypto0698_1.htm responsabilité pénal. civil le et plan sur responsabilité sa à engagera tiers, des ou laboratoire au créé - En particulier, l'utilisateur doit faire preuve de la plus grande correction à l'égard de ses - Les liens sur d'autres serveurs à partir principalesdesloisRappel9- françaises Il est rappelé que toute personne sur le sol français doit respecter la : informatique sécurité de la particulier législation française en - http://www.cnil.fr/ ) et "informatique loi 6/1/78 liberté",(cf. du dite la - la législation relative à la fraude informa - intellectuelle(cf. propriété législationà la relative la ) http://www.legifrance.gouv.fr/citoyen/code.cgi - la loi- du 04/08/1994 relative la Responsabilités 10- à l'emploi législation dela Chaque applicable utilisateur accède et utilise les moyens informatiques et languele réseau sous sa propre - française,(cf. en Il reconnaît que toute violation des dispositions de la charte et tout dommage de son fait matièreJe soussigné : le LIAFA sigle : sous serveurs du les compte sur d'un détenteur de déclare avoir pris connaissance de cryptologie.(cf. la recommandations. ses respecter charte divers instituts et de chartes desuniversités. inspirée est charte Cette Création: 1997 mars à mise2003 : jour Dernière

28 Chapitre 2

Projet scientiﬁque du laboratoire

Ce chapitre decrit´ le projet scientiﬁque gen´ eral´ du LIAFA pour le prochain quinquennat (2014-2018), debutant´ au 01/01/2014. Il pourrait toutefois etreˆ mis en œuvre des` 2013, sous reserve´ de validation par l’AERES. De fait, ce projet est en continuite´ des actions entreprises ces dernieres` annees´ par le laboratoire. Il ne se substitue pas aux projets scientiﬁques de chacune des equipes´ du LIAFA, tels que decrits´ dans chacun des rapports d’equipe.´ En revanche, il offre un cadre gen´ eral´ dans lequel chacun de ces projets d’equipe´ pourra s’inscrire.

2.1 Positionnement scientiﬁque et objectif gen´ eral´

L’objectif du LIAFA est de se positionner nationalement et internationalement en tant qu’acteur majeur en informatique fondamentale, definie´ comme l’ensemble des activites´ scientifiques ayant pour objectif d’apprehender´ et de comprendre la nature des modes de calcul, d’en concevoir les theories,´ et de developper´ les outils permettant la conception et l’analyse de calculs efficaces (corrects, rapides, etc.). Le laboratoire est actuellement dej´ a` identifie,´ et bien reconnu, en informatique fondamentale, graceˆ aux activites´ de ses equipes.´ L’ambition du LIAFA est d’aller au-dela` de l’addition des performances de ses equipes´ pour developper´ a` court/moyen terme, au sein de l’Universite´ Paris Diderot et du CNRS, un lieu d’excellence en informatique fondamentale, visible internationalement et identifie´ en tant que tel. Ce projet pourrait a` plus long terme deboucher´ sur la creation´ d’un Institut d’Informatique Fondamen- tale a` Paris Diderot. Un institut d’informatique fondamentale ne pourrait toutefois voir le jour a` Paris Diderot sans concertation avec les autres acteurs en informatique de l’universite,´ dont bien surˆ le laboratoire PPS. En fait, il ne pourrait voir le jour sans la participation effective de ces acteurs. Le projet du LIAFA tel que decrit´ dans ce rapport n’abordera donc pas directement le sujet de la creation´ d’un tel institut, memeˆ si cette creation´ peut etreˆ gardee´ en toile de fond de la description du projet de l’unite,´ en particulier pour ce qui touche au rapprochement avec PPS. Le texte ci-dessous se cantonnera plutotˆ a` resumer´ brievement` la politique que compte mettre en œuvre le LIAFA pour augmenter encore sa visibilite´ et son impact scientifique dans le domaine de l’informatique fondamentale.

Les trois piliers soutenant le projet. L’evolution´ thematique´ du LIAFA ces dernieres` annees,´ en particulier l’elargissement´ de son spectre de competences,´ est l’un des trois piliers sur lesquels le laboratoire compte s’appuyer pour realiser´ son objectif. Les thematiques´ de recherches du laboratoire incluent en effet maintenant la quasi-totalite´ des thematiques´ liees´ a` l’informatique fondamentale au sein de la nouvelle section 06 du CNRS ¾ Sciences de l’information : fondements de l’informatique, calculs, algorithmes, representations,´ exploitations ¿, a` savoir : • algorithmique, combinatoire, graphes, automates, systemes` dynamiques discrets ; • logique, complexite´ algorithmique et structurelle, semantique,´ modeles` de calcul ; • veriﬁcation´ ;

29 CHAPITRE 2. PROJET SCIENTIFIQUE DU LABORATOIRE

• reseaux,´ reseaux´ sociaux, systemes` distribues,´ calcul distribue´ ; • bioinformatique. Le laboratoire possede` donc a` ce jour une assise suffisamment large en informatique fondamentale pour batirˆ un projet specifique´ a` cette thematique,´ visant a` sa promotion scientifique et a` l’identification du LIAFA comme acteur central en son sein. Le deuxieme` pilier sur lequel l’unite´ compte s’appuyer est son appartenance a` plusieurs structures scientifiques nouvelles, dont le LABEX Sciences Mathematiques´ de Paris (SMP) et l’IDEX Sorbonne Pa- ris Cite´ (SPC). Le LABEX SMP permet dej´ a` de promouvoir l’interaction avec les mathematiques,´ et, prosa¨ıquement, d’acceder´ a` un ensemble de ressources capitales (post doc, invitations, etc.) pour la mise en œuvre du projet du LIAFA. L’IDEX SPC devrait quant a` lui permettre, entre autre, de renforcer pour certaines thematiques´ les liens entre le laboratoire et certaines equipes´ d’autres laboratoires parisiens, dont le LIPN (membre de l’IDEX). Enfin, le troisieme` pilier sur lequel le laboratoire compte s’appuyer est sa proximite´ scientifique et geographique´ avec PPS. Au dela` des problemes` de structure qui ont et´ e´ evoqu´ es´ plus haut dans ce rapport, l’ambition du LIAFA ne saurait se realiser´ sans un rapprochement avec PPS sur de nombreuses thematiques´ qui, quoiqu’abordees´ actuellement de manieres` parfois differentes,´ rev´ elent` de nombreux points d’accroche sur plusieurs problematiques´ centrales de l’informatique fondamentale.

Une mise au point sur la couverture thematique.´ Avant de decrire´ plus avant le projet du LIAFA, il convient de souligner que le laboratoire n’a evidemment´ pas comme ambition de couvrir tout le champ de l’informatique fondamentale, et encore moins de se substituer aux equipes´ presentes´ sur le sujet en region´ parisienne. A titre d’exemple, le LIAFA ne dispose pas de forces en calcul formel (LIP6), en arithmetique´ des ordinateurs (LIP6), en geom´ etrie´ algorithmique (ENS-INRIA), etc. Le laboratoire ne compte pas a priori developper´ des activites´ sur ces themes.` En revanche, il compte maintenir ou creer´ des liens avec ces equipes´ aﬁn de garder une certaine proximite´ avec des thematiques´ cruciales au sein de l’informatique fondamentale. La proximite´ avec des equipes´ du LIENS (membre, comme le LIAFA, de la fondation SMP), du LIP6 (sur les themes` mentionnes´ ci-dessus, voir egalement´ en algorithmique distribuee´ et en combinatoire), de Telecom ParisTech (en algorithmique quantique, par exemple, et autour de la theorie´ des automates), du LIPN (en combinatoire), du LIGM (en automates et combinatoire) ou encore du LSV (en veriﬁcation),´ sont autant d’atouts sur lesquels compte s’appuyer le LIAFA pour le developpement´ de son projet en gen´ eral´ et de celui de chacune de ses equipes´ en particulier.

Strategie´ de mise en œuvre. L’ambition du LIAFA d’affirmer sa position de leader en Informatique Fondamentale necessite´ • d’une part de creer´ des axes de synergie entre ses equipes,´ et • d’autre part d’elargir´ encore son spectre de competences.´ Les axes de synergie internes au laboratoire sont decrits´ dans la section suivante (section 2.2). L’elargissement´ du spectre de competences´ du laboratoire repose evidemment´ sur sa capacite´ a` recruter, mais aussi sur l’identification de points d’accroche scientifiques entre le LIAFA et PPS. Ces points d’accroche sont en cours d’identification par les deux UMR. Une liste non exhaustive resultant´ de discussions preliminaires´ entre le LIAFA et PPS est decrite´ dans la section 2.3.

2.2 Axes fed´ erateurs´ internes et implications externes

Cette section decrit´ trois directions de recherche gen´ erales´ ayant pour objet, d’une part, de renforcer la synergie entre les equipes´ du laboratoire, et, d’autre part, de promouvoir les recherches du laboratoire a` l’externe, au dela` du positionnement national ou international de telle ou telle equipe,´ ou de tel

30 CHAPITRE 2. PROJET SCIENTIFIQUE DU LABORATOIRE ou tel groupe de chercheurs du laboratoire. Ces trois directions sont structurees´ autour de trois axes transversaux : • algorithmique, • systemes` concurrents, • structures et logique, jeux. Les trois sous-sections ci-dessous decrivent´ chacun de ces axes transversaux, en speciﬁant´ leur mise en œuvre au sein du LIAFA.

2.2.1 Algorithmique

Si tout informaticien, et de nombreux mathematiciens´ et physiciens, conçoivent et analysent des algorithmes au quotidien, l’etude´ proprement dite des techniques de conception d’algorithmes n’est de fait pas une force de l’informatique en France. Le pays a ainsi, a` l’exception des travaux de quelques personnalites,´ globalement manque´ les revolutions´ successives des algorithmes d’approximation, des algorithmes probabilistes, des algorithmes ¾ on-line ¿, des algorithmes de ¾ streaming ¿, etc., sans memeˆ parler du ¾ property testing ¿, de la complexite´ de la communication, ou d’autres thematiques´ algorithmiques connexes. Ainsi, les reussites´ scientifiques nationales telles que le projet Algorithmes a` l’IN- RIA, le developpement´ de l’algorithmique quantique au LRI a` Orsay au debut´ des annees´ 2000, voire les succes` de l’ecole´ française en algorithmique distribuee,´ ne doivent pas cacher une relative faiblesse de la France en ce qui concerne le developpement´ de nouveaux concepts algorithmiques et l’analyse en complexite´ de problemes,` au moins pour ce qui concerne les modeles` les plus modernes mentionnes´ ci-dessus. La presence´ au laboratoire de plusieurs acteurs français parmi les plus eminents´ en algorithmique et en complexite´ incite le LIAFA a` œuvrer afin de supporter toutes les activites´ scientifiques en liaison avec ces thematiques.´ Cela consiste evidemment´ pour une part a` promouvoir en son sein l’etude´ de la conception et l’analyse d’algorithmes. (Cette promotion pourra par exemple s’effectuer sous la forme de support a` des groupes de travail thematiques´ transversaux, tel que celui recemment´ anime´ par Sylvain Perifel sur la complexite.)´ Au dela,` le LIAFA estime qu’il se doit de jouer un roleˆ national pour aider au developpement´ de competences´ en conception et en analyse d’algorithmes en France. Cette volonte´ s’est dej´ a` traduite par l’organisation de l’Ecole de Printemps d’Informatique Theorique´ (EPIT) en 2012 sur le theme` de l’algorithmique probabiliste, et par la creation´ du groupe de travail Complexite´ et Algorithmes (CoA) au sein du GdR Informatique Mathematique´ (IM), sur l’initiative de membres du laboratoire. Ces initiatives devraient se poursuivre a` l’avenir, sous forme d’outils perennes´ (tels que les journees´ ALEA ou les rencontres AlgoTel, sur des sujets connexes). En resum´ e,´ le LIAFA compte poursuivre son effort en algorithmique, alliant renforcement des competences´ locales, implication dans la communaute´ informatique nationale, et augmentation de sa visibilite´ internationale.

2.2.2 Systemes` concurrents

Les systemes` concurrents incluent tous les systemes` dans lesquels un ensemble d’entites´ informatiques (processeurs multi-cœurs au sein des ordinateurs, ¾ cloud computing ¿, etc.), d’acteurs humains (economiques,´ sociaux, etc.), voire d’autres organismes vivants (colonie de fourmis, bacteries,´ etc.), in- teragissent de fac¸on plus ou moins coordonnee.´ Ces systemes` ont envahi notre quotidien. Comprendre, utiliser, controler,ˆ et/ou securiser´ ces systemes` est une problematique´ gen´ erale´ dont l’importance n’ira que croissante dans les annees´ a` venir. Cet etat´ de fait a ainsi et´ e´ naturellement souligne´ lors des recentes´ reunions´ du GT 1 d’ALLISTENE 1. Or, tout comme pour ce qui concerne l’algorithmique (cf. sec-

1. Alliance des sciences et technologies du numerique.´ Partenaires : CDEFI (Conference´ des Directeurs des Ecoles´ Franc¸aises d’Ingenieurs),´ le CEA, le CNRS, la CPU (Conference´ des Presidents´ d’Universites),´ INRIA et l’Institut Telecom.

31 CHAPITRE 2. PROJET SCIENTIFIQUE DU LABORATOIRE tion 2.2.1), le LIAFA compte en son sein de nombreux specialistes´ des systemes` concurrents. Il s’avere` toutefois que ces specialistes´ sont disperses´ au sein des differentes´ equipes´ du laboratoire, et abordent cette thematique´ sous differentes´ formes, de la verification´ a` l’algorithmique distribuee,´ en passant pas les automates cellulaires et les automates asynchrones. Ce n’est pas inherent´ au LIAFA puisque leurs communautes´ internationales sont egalement´ relativement disjointes. Le LIAFA compte renforcer ses activites´ de recherche sur les systemes` concurrents, en particulier la verification´ de ces systemes,` la comprehension´ de leur dynamique, et l’etude´ de la conception d’algorithmes efficaces pour les systemes` distribues.´ Le laboratoire œuvrera donc afin, d’une part, de renforcer equipes´ ou groupes de chercheurs traitant des systemes` concurrents, et d’autre part, de fed´ erer´ toutes les activites´ scientifiques au LIAFA traitant de la concurrence. Le renforcement de telle ou telle thematique´ pourra s’effectuer sous la forme classique de flechage´ de ressources. A titre d’exemple, un des postes demandes´ en 2012 par l’UFR Informatique aupres` de l’universite´ Paris Diderot touche directement a` la verification´ de systemes` concurrents. Le rapprochement des differentes´ thematiques´ liees,´ sous une forme ou une autre, aux systemes` concurrents est un objectif d’une beaucoup plus grande ampleur. La rarete´ des mouvements inter-salles lors de l’organisation conjointe des conferences´ annuelles PODC 2 et CONCUR 3 illustre a` elle seule la difficulte´ de rapprocher des communautes´ travaillant sur differents´ aspects d’un memeˆ objet scientifique. Neanmoins,´ le LIAFA œuvrera au rapprochement entre les differents´ membres du laboratoire interess´ es´ par les problemes` lies´ aux systemes` concurrents, en particulier au moyen de groupes de travail transversaux sur des themes` tels que les systemes` distribues´ et les systemes` dynamiques discrets. Ce projet ne pourra toutefois etreˆ pleinement realis´ e´ qu’en synergie avec le laboratoire PPS qui possede` une expertise complementaire´ en programmation dite concurrente (calcul de processus, pi-calcul et extensions, etc.) et mobile. Le rapport reviendra donc sur le theme` de la concurrence en section 2.3 dans la partie traitant du rapprochement avec PPS.

2.2.3 Structures et logique, jeux

Le troisieme` axe transversal sur lequel le laboratoire compte s’appuyer pour augmenter la synergie entre les equipes´ a trait d’une part a` la logique et ses liens avec differentes´ structures, dont en particulier celles issues de la theorie´ des graphes mais aussi de la combinatoire ou de l’algebre,` et, d’autre part, aux jeux. Il s’agit de deux thematiques´ qui, conjointement ou separ´ ement,´ sont susceptibles d’apporter de la valeur ajoutee´ aux recherches du LIAFA par une augmentation des interactions entre les equipes.´ La logique offre un cadre sophistique´ pour specifier´ des propriet´ es´ de structures, dans lequel s’inserent` une grande partie des travaux des equipes´ Automates et applications et Modelisation´ et verification,´ mais egalement´ de l’equipe´ Algorithmes et complexite.´ Le LIAFA souhaite donc renforcer les points de contact entre les equipes´ sur ces themes` afin d’ameliorer´ encore l’expertise des membres du laboratoire sur ces sujets, et developper´ de nouvelles collaborations. A` titre d’exemple, on peut penser aux travaux inities´ par Bruno Courcelle (LaBRI) montrant les liens entre la complexite´ des problemes` de ¾ model-checking ¿ pour les graphes et les propriet´ es´ structurelles de decomposition´ (arborescente, clique, etc.) de ses derniers. Ces problematiques´ peuvent naturellement engendrer des collaborations entre les equipes´ Algorithmique distribuee´ et graphes et Modelisation´ et verification.´ Une autre collaboration inter-equipe´ sur ce sujet peut etreˆ motivee´ par les resultats´ recents´ de Friedmann, Hansen et Zwick sur la complexite´ des problemes` lies´ aux jeux de parite´ ¾ mean payoff ¿, qui correspondent en fait a` des problemes` de ¾ model-checking ¿ pour des graphes finis. Par les techniques employees,´ et par les problemes` etudi´ es,´ ces travaux encouragent des connexions entre les equipes´ Algorithmes et complexite,´ Automates et applications, et Modelisation´ et verification.´

2. ACM Symposium on Principles of Distributed Computing. 3. International Conference on Concurrency Theory.

32 CHAPITRE 2. PROJET SCIENTIFIQUE DU LABORATOIRE

Par ailleurs, et en liaison directe avec les thematiques´ ci-dessus, le laboratoire dispose d’une forte expertise dans le domaine des jeux. Ceci inclut evidemment´ les jeux pour la theorie´ des modeles` (a` la Ehren- feucht–Fra¨ısse),´ les jeux stochastiques et/ou a` information imparfaite sur des graphes pour la veriﬁcation´ de systemes,` la conception de mecanismes´ incitatifs (¾ mechanism design ¿), mais aussi la theorie´ des jeux ¾ classique ¿ : jeux matriciels, equilibre´ de Nash et variantes, jeux a` agents ego´ ¨ıstes rationnels, etc. L’expertise du LIAFA reste toutefois fragmentee´ entre les equipes,´ malgre´ des participations conjointes a` des structures de recherche nationales (par exemple, le GT Jeux du GdR IM et, dans une moindre mesure, le GdR Theorie´ des Jeux et le GdR Recherche Operationnelle).´ Le laboratoire portera donc une attention particuliere` au developpement´ d’activites´ inter-equipes´ sur les jeux. Ce tout dernier point est en fait en liaison directe avec le rapprochement LIAFA-PPS discute´ dans la section suivante.

2.3 Rapprochement LIAFA-PPS

Cette section decrit´ le troisieme` pilier (outre l’identiﬁcation d’axes transversaux et l’appartenance au LABEX SMP) sur lequel le LIAFA a construit son projet, a` savoir un elargissement´ du spectre de ses competences´ par un rapprochement scientiﬁque avec le laboratoire PPS. Cette section a ainsi et´ e´ partiellement redig´ ee´ en coordination avec la direction de PPS. Le rapprochement avec PPS repose principalement sur deux outils : un ensemble de groupes de travail communs sur des thematiques´ d’accroche entre les deux unites,´ et un ou plusieurs seminaire(s)´ commun(s), dont un seminaire´ didactique.

2.3.1 Thematiques´ d’accroche

Les discussions menees´ entre les deux laboratoires LIAFA et PPS en 2011-2012 dans le cadre de la demande de fusion initiee´ par l’INS2I, et tout particulierement` celles tenues depuis quelques mois, ont permis d’identifier tout un ensemble de thematiques´ scientifiques sur lesquelles des equipes´ des deux laboratoires pourraient sinon collaborer, au moins interagir afin d’elargir´ leur expertise. La liste ci-dessous donne un ordre d’idee´ de ces thematiques,´ sans pretendre´ a` l’exhaustivite´ puisque tout rapprochement conduit a` l’identification parfois inattendue d’autres points de convergence.

Jeux. La semantique´ des jeux est un domaine important d’inter´ etˆ pour PPS, en particulier lie´ a` la modelisation´ de differentes´ primitives de programmation, dont les fonctions, le controle,ˆ les etats,´ le non-determinisme,´ etc., tout en restant proche des langages de programmation. Cet inter´ etˆ est en adequation´ avec celui du LIAFA pour les jeux et leurs applications en theorie´ des automates et en verification.´ Par exemple, certains des travaux recents´ sur la verification´ des schemas´ recursifs´ d’ordre superieur´ dans l’equipe´ Automates et applications reposent de façon cruciale sur des arguments de semantique´ des jeux, tandis que d’autres permettent de s’en passer. Comprendre les liens entre la semantique´ des jeux et les logiques de points fixes pour des structures recursives´ necessite´ une expertise partagee´ par les membres des deux laboratoires. Ces questions seront au cœur de la these` de C. Grellois co-encadree´ par Paul-Andre´ Mellies` (PPS), Olivier Serre (LIAFA) et Luke Ong (Oxford University), et debutant´ en septembre 2012. Notons par ailleurs que la semantique´ des jeux (etudi´ ee´ a` PPS) procede` selon les principes de la semantique´ des traces en theorie´ de la concurrence (etudi´ ee´ au LIAFA). Parallelisme´ et distribue.´ Le LIAFA et PPS travaillent respectivement sur differents´ aspects de la concurrence. Dans ce cadre, ils sont conduits a` utiliser les memesˆ outils, dont en particulier certains issus de la topologie algebrique.´ A titre d’exemple, l’acces` concurrent a` des ressources ex- clusives est etudi´ e´ par PPS a` partir d’une modelisation´ utilisant la topologie algebrique´ orientee´ (cf les travaux d’Eric Goubault au CEA). De façon semblable, les algorithmes pour les systemes` asynchrones a` memoire´ partagee´ sont etudi´ es´ au LIAFA a` partir d’une modelisation´ de l’execution´ des algorithmes par des subdivisions de complexes simpliciaux. Ce point commun entre PPS et

33 CHAPITRE 2. PROJET SCIENTIFIQUE DU LABORATOIRE

LIAFA est illustre´ par la participation conjointe de membres des deux laboratoires au Dagstuhl Seminar 12121 : ¾ Applications of Combinatorial Topology to Computer Science ¿. Combinatoire et series´ formelles. Les deux laboratoires travaillent chacun sur des thematiques´ les amenant a` utiliser intensivement la theorie´ des series´ formelles. En particulier, cela transparaˆıt a` PPS au travers de l’etude´ de la theorie´ des especes` combinatoires, de laquelle derive´ une methode´ systematique´ pour analyser des structures discretes` au moyen de fonctions gen´ eratrices,´ avec des applications importantes au calcul des substitutions. Et bien evidemment,´ les series´ formelles sont un objet quotidien d’etude´ et d’utilisation par l’equipe´ Combinatoire du LIAFA, mais egalement,´ dans une moindre mesure, de l’equipe´ Automates et applications et de l’equipe´ Modelisation´ et verification.´ L’identification de ce theme` est recente,´ et n’a pas encore donne´ lieu a` des operations´ communes de la part des deux laboratoires. Il s’agit d’un sujet neanmoins´ porteur sur lequel LIAFA et PPS comptent collaborer. Preuve, certification, verification.´ Evidemment, les points de convergence sont nombreux entre les deux laboratoires sur la thematique´ gen´ erale´ de la preuve et de la verification.´ Cela dit, les details´ rev´ elent` de grandes differences´ entre les objectifs et methodologies´ des deux laboratoires. Il est possible toutefois d’identifier deux points d’accroche : la verification´ de composants logiciels, et l’etude´ des graphes de dependances´ entre composants logiciels (typiquement LINUX), tous deux en liaison directe avec les efforts de recherche a` PPS relatifs au deploiement´ de logiciels libres. Des relations informelles existent entre PPS et LIAFA sur les deux themes,` impliquant respectivement les equipes´ Modelisation´ et verification´ et Algorithmique distribue´ et graphes du LIAFA. Il conviendra de pousser plus avant ces contacts afin de rendre possibles de reelles´ interactions entre les deux laboratoires sur ces deux sujets. Concurrence. La concurrence est l’un des trois axes transversaux du LIAFA mentionnes´ ci-dessus dans son projet. Cette thematique´ fait evidemment´ egalement´ partie des centres d’inter´ etsˆ de PPS, en particulier au travers de l’etude´ des programmes ¾ multi-threads ¿ ou de la programmation par ev´ enements.´ Nous avons egalement´ mentionne´ plus haut dans ce rapport combien la concurrence etait´ au centre des preoccupations´ du LIAFA, en particulier au travers de la verification´ de programmes concurrents et de l’algorithmique distribuee.´ Les laboratoires PPS et LIAFA ont convenu d’unir leurs efforts sur ce theme` afin de faire de la concurrence un domaine de convergence entre les deux unites.´ La forme que pourrait prendre cet effort reste toutefois a` arbitrer, entre un groupe de travail specifique´ ou un ¾ chapeau ¿ aux thematiques´ mentionnees´ ci-dessus, dont ¾ jeux ¿ et ¾ parallelisme´ et distribue´ ¿.

En guise de conclusion a` cette section, il convient de noter qu’il existe d’autres points d’accroche potentiels entre les deux laboratoires, lies´ a` des activites´ individuelles de certains membres d’une ou l’autre des deux unites.´ Un exemple typique est la conception de protocoles de routage pour les reseaux´ radio ad hoc, ou la conception de protocoles P2P. Ces domaines d’inter´ etˆ sont au cœur des preoccupations´ de l’equipe-projet´ INRIA GANG au LIAFA. De son cotˆ e,´ et de maniere` independante,´ Juliusz Chroboczek (PPS) a depos´ e´ un RFC (numero´ 6126) aupres` de l’IETF en 2011 pour son protocole de routage Babel, et a conc¸u des extensions de BitTorrent. Ceci illustre que les potentiels de collaborations entre le LIAFA et PPS sont nombreux, et ne sont certainement pas limites´ a` la liste ci-dessus.

2.3.2S eminaire´ didactique

Plus globalement, les deux laboratoires devraient se doter d’outils visant a` donner a` chaque membre du LIAFA et de PPS un niveau convenable de culture et de competences´ relatives a` chacune des thematiques´ nombreuses abordees´ par les deux unites.´ Ceci pourrait prendre la forme d’un seminaire´ didactique regulier.´ Nous insistons sur le terme ¾ didactique ¿ car l’objectif serait bien de permettre a` tous d’acquerir´ des competences´ , dans le but d’assurer une cohesion´ entre l’ensemble des chercheurs et enseignants-chercheurs des deux laboratoires.

34 CHAPITRE 2. PROJET SCIENTIFIQUE DU LABORATOIRE

2.4 Analyse SWOT

La figure 2.1 resume´ l’analyse SWOT 4 du projet du laboratoire. Certains points sont detaill´ es´ ci-dessous, sans revenir toutefois sur les points dej´ a` evoqu´ es´ plus haut dans le document. Le laboratoire tient a` souligner non seulement la difficulte´ de promotion des Maˆıtres de Conferences,´ dej´ a` evoqu´ ee´ plus haut, mais aussi la tres` grande difficulte´ d’obtenir des promotions pour les ITA (les quatre personnels administratifs et techniques sont tous CNRS). Sur le long terme, ces difficultes´ de promotion font peser le risque d’une demotivation´ des personnels concernes.´ Une autre faiblesse du laboratoire tient au fait qu’il se situe au cœur de l’Informatique, sans etreˆ toutefois un laboratoire ¾ gen´ eraliste´ ¿. Ainsi, pese` le risque d’un retard dans la perception de l’importance de thematiques´ nouvelles liees´ a` des innovations technologiques. Une certaine veille, comme la presence´ dans des GdR plus appliques,´ comme par exemple ASR, peut toutefois aider a` limiter ce risque. Le relatif peu d’attrait exprime´ par la majorite´ des membres du laboratoire envers les applications se traduit d’ailleurs par un faible rendement du LIAFA en terme de valorisation et de developpement´ logiciel. Certes, on ne peut pas etreˆ ¾ au four et au moulin ¿, mais il n’empecheˆ qu’un effort de valorisation serait evidemment´ bienvenu, sans pour autant modifier la nature des recherches menees´ au sein du laboratoire. La qualite´ gen´ erale´ des theses` du laboratoire est remarquable. Cela est en partie duˆ a` l’attention toute particuliere` portee´ par les membres du laboratoire envers le recrutement de leurs etudiants.´ Cette politique de recrutement elitiste´ des doctorants (qui, certes, pourrait etreˆ critiquee)´ repose en grande partie sur la qualite´ des etudiants´ de master issus du MPRI. Notons en particulier que la these` d’Andre´ Chailloux (el´ eve` du MPRI, these` au sein de l’equipe´ Algorithmes et complexite)´ a obtenu le dernier prix Gilles Kahn en 2011. Faire reposer le recrutement des doctorants sur un unique master est toutefois une relative menace. Le laboratoire a donc entrepris d’elargir´ son spectre de recrutements vers l’international, incluant des co-tutelles au niveau doctorat et l’attraction d’etudiants´ etrangers´ afin d’alimenter le MPRI au niveau master. La presence´ du LABEX SMP est sur ce point, entre autres, une source d’opportunites´ qu’il conviendra de saisir. Le LIAFA se doit neanmoins´ de rester attentif concernant sa politique de recrutement de ses doctorants afin de preserver´ la qualite´ des doctorants tout en augmentant son taux d’encadrement (qui demeure relativement faible, malgre´ une croissance de 1 a` 1,2 entre 2007 et 2012). Le laboratoire depend´ majoritairement des programmes de l’ANR, tout particulierement` des programmes ¾ Blancs ¿ et ¾ JCJC ¿, pour l’obtention de ressources propres. La relative etroitesse´ de ces sources de financement fait evidemment´ peser une menace sur les ressources financieres` du LIAFA. Quelques equipes´ ont obtenu des financements europeens´ (par exemple des STREP 5). Egalement, le laboratoire peut s’orgueillir d’une certaine reussite´ aupres` de l’ERC lors des recents´ appels. Il conviendra de renforcer ces efforts afin de diversifier les sources de financement de l’unite.´ Enfin, l’IDEX Sorbonne Paris Cite´ est mentionne´ dans le diagramme dans la rubrique ¾ opportunite´ ¿, pour les raisons mentionnees´ prec´ edemment´ dans le rapport. Il convient de noter que ce memeˆ IDEX est egalement´ partiellement source sinon de menaces au moins de difficultes.´ Ainsi, la Fondation SMP est a` cheval sur plusieurs IDEX, et la potentielle creation´ d’une unique universite´ regroupant les entites´ actuelles de l’IDEX n’ira pas sans peser sur des structures telles que l’UFR d’Informatique de Paris Diderot, voire ses laboratoires.

4. Force (Strength), Faiblesse (Weakness), Opportunite´ (Opportunity), Menace (Threat). 5. Speciﬁc Targeted Research Projects.

35 CHAPITRE 2. PROJET SCIENTIFIQUE DU LABORATOIRE

INTERNE

–faible taux d’encadrement –risque d’isolement culturel

au sein de la discipline e´ –difﬁcult informatique eit´ en´ –peu de valorisationpour les MdC et e´ de publications e´ de promotion de d eveloppement logiciel e´ et homog ´

– forte activit Faiblesse – nombreux personnelse´ internationale CNRS ematique´ – continuitth Force – visibilitde nombreux membres NEGATIF S W

POSITIF O T Opportunit –rapprochement LIAFA-PPS –fondation SMP –IDEX Sorbonne Paris Cit Menace e´ etroite´ etroit´

etudiants´

– lenteur des promotions ITA e´ – vivier d’ – source de ﬁnancement

EXTERNE

FIGURE 2.1 – Analyse SWOT du projet 2014-2018 du LIAFA

36 Part II

Algorithms and Complexity team

Chapter 1

Research report: Algorithms and Complexity

1.1 Research areas and main objectives

1.1.1 Development of the team

The current “Algorithms and Complexity” team was part of the “Algorithms and Complexity” team of LRI until November 1, 2010 when, at our request, it was transferred by a decision of the President of the CNRS to LIAFA. The combinatorics and graph theory part of the LRI team stayed in LRI, it is the part of the team whose research concentrates on classical and quantum algorithms and complexity that moved to LIAFA. The move involved 5 CNRS researchers (Kempe, Kerenidis, Magniez, Rosen´ and Santha) and a Professor at Pantheon-Assas´ (de Rougemont) who performs his research in LIAFA. The situation of S. Laplante, Professor at Paris-Sud, remained somewhat particular: while an associate member of, and in practice present at LIAFA, she stayed officially for her research at LRI. We hope that she will move soon as Professor to Paris Diderot: on May 11 she was ranked 1st for a position by the Selection Committee. Since the move there were two changes: D. Xiao was hired as a CNRS researcher in October 2011, and J. Kempe left the team en “detachement”´ in December 2011. The move to LIAFA was the result of a long and arduous process that started in 2007. The reasons of the move were manifold. If we have to summarize them in one sentence, we felt that the quality of our scientific work could only be kept, and the cohesion of the team could only be safeguarded in Paris. And if we want to summarize again in one sentence our current situation: we are satisfied with our life in LIAFA, and while it is too early to assess the global outcome, we feel that in many aspects our objectives were achieved or are in the process of being achieved. We describe now more in details the outcomes of the move in the relatively short period since November 2010 in three fields: research, scientific policy, and teaching. Being in LIAFA has improved substantially our research environment. The number of our prospective international visitors has significantly increased with respect to the previous years. Similarly, the quality of the candidates for our postdoc positions was much higher in 2012 than before: among the more than forty applicants there were several graduates from the topmost US universities. We strengthened or improved our ties with several research teams in Paris. With Tel´ ecom´ Paris-Tech we keep on co-organizing the trimestrial “Quantum Information Day in Paris”. We have a joint ANR “Jeunes Chercheurs ” project with them, and a PhD student is co-advised by the two teams in the framework of this project. With the cryptography group of the ENS LIENS we co-organize a “cryptography-complexity” day in June 2012. Our application with the geometry, combinatorics, and algorithms group of the same laboratory for a joint ANR BLANC grant RDAM has been very recently accepted. We currently have a joint ANR blanc project with LIP6, entitled “New Technniques in Online Computation (NeTOC)”, 2012-2105. In March 2012 at the Ile de Re´ we organized the Ecole de Printemps d’Informatique Theorique´ on probabilistic algorithms where the lecturers came, beside from our team, from LIAFA, ENS, and from abroad.

39 CHAPTER 1. RESEARCH REPORT: ALGORITHMS AND COMPLEXITY

Concerning scientific policy, we believe that inside LIAFA we play a dynamic role including various collaborations with the other teams, and in the Universite´ Paris Diderot we have an increasing visibility. Our weekly seminar regularly attracts persons of the laboratory, and we also often attend the seminars and working groups of some of the other teams. We had a successful joint application with the “Distributed Algorithms and Graphs” team for a postdoctoral position at the Fondation Sciences Mathematiques´ de Paris (unfortunately the applicant choose an assistant professor position at Stanford). Nicolas Schabanel, a member of the same team is also part of our new joint LIAFA-LIENS ANR grant RDAM. With the “Equipe de Logique” of Paris Diderot we led the ANR project VERAP (2007-2011) on approximate verification and plan to jointly explore new subjects related to the approximate enumeration of solutions. We co-organized in January 2012 at Paris Diderot the annual workshop of the GdR “Informatique Mathematique”,´ and with the Fed´ eration´ de Recherche en Mathematiques´ de Paris Centre we organized a two days workshop in May 2012 on quantum information theory with the participation of computers scientists, physicists and mathematicians. We teach in two Master programs (M2) associated with Paris Diderot, in the Master “Logique Mathematique´ et Fondements de l’Informatique” and in the “Master Parisien de Recherche en Infor- matique”. Since we moved to Paris we are much closer to the students, our contacts with them became more frequent, regular and fruitful. We reorganized several of our courses in the MPRI, and we established a rotating teaching including also Nicolas Schabanel. Starting 2013 we plan to teach a joint course with the ENS LIENS. We also have a new project course for M1 and M2 Pro years at Paris Diderot on randomized and approximation algorithms. Last, we are involved at Ecole Polytechnique in its teaching program (L3 and M1). We would like to shortly assess the main points of the AERES March 2009 evaluation of the team (still at LRI at that time). We consider that we kept our strong points: our scientific quality, our network of international collaborations and our attractiveness. We had 12 publications in the SIAM Journal on Computing, 5 publications in Algorithmica, and we have published 11 papers in IEEE FOCS/ACM STOC, 6 papers in Conference on Computational Complexity and 7 papers in ICALP. We participated in 3 EU projects (one integrated, one STREP, one CHISTERA), several international projects (with Canada, Hungary, Japan and one with various Asian countries), we lead an LEA with Israel and we participate in an UMI with Japan and in an LIA with Singapore. In quantum computing we belong to the few best teams in the world. While in classical computing we are not at the same level, our quality is high, and our work is acknowledged by the community. We have successfully initiated studies in new models of computing, such as streaming algorithms, and strengthened our position in online algorithms and algorithmic game theory. The arrival of David Xiao had extremely positive effects on the team: his expertise in learning theory, complexity and classical cryptography very nicely completed our research directions. The move to LIAFA made our scientific cohesion stronger: we are a very coherent team, we know and appreciate each other’s work, and we can together fully concentrate on the domains where we are the best. We think that we have successfully addressed at least two of the three critical remarks of the 2009 evaluation. Our scientific influence in LIAFA is certainly much stronger than it was in LRI, we naturally have common interests with several other teams and, as we described in the outcomes of our move, we have initiated several joint actions. We believe that we have also seriously strengthened our involvement in the national computer science research framework. Again, as described above, our move to LIAFA created for us a more favorable research environment inside Paris Diderot. But our involvement has increased also independently from the move. We play a leading role in the GDR Informatique Mathematique´ and the GDR Information Quantique, Fondements & Applications where we regularly organize yearly workshops and also participate in meetings outside our immediate workgroups, such as ALEA. We have worked to expand our presence both locally, for example by organizing events and joint projects with ENS, as well as nationally, for example speaking at the annual meeting of the Societ´ e´ Mathematiques´ de

40 CHAPTER 1. RESEARCH REPORT: ALGORITHMS AND COMPLEXITY

France. We also hope that the March 2012 Ecole de Printemps has also contributed to mark our position as a central player in theoretical computer science community in France. While it is too early to judge the long term effects of our installation to LIAFA for the formation of PhD students, we think that we move also here in the right direction. Three new PhD students have started their doctorate last year, and we have (co-)directed several master theses both from MPRI and from Canada in the framework of the CSQIP training program. And, of course, we were very proud that Andre´ Chailloux has won the Gilles Kahn prize in 2011.

1.1.2 Description of our main scientiﬁc results

1.1.2.1 Classical algorithms and complexity

Property Testing Randomization and also approximation are important tools in algorithmic whose number of applications increases dramatically with the new challenges of modern computer science. We are particularly interested in the design of sublinear algorithms, i.e. algorithms that do not read all of their input. Such algorithms were pioneered by Property Testing, a statistics based approximation technique to decide whether an input satisfies a given property, or is far to any input satisfying the property. In this area, we initiated the study of property testing for the edit distance with moves in the contexts of words [FMR10], XML databases [CJR08] and Markov Decision Processes [RT09]. Streaming and Online Algorithms Another challenge is to handle restrictive accesses to the input. Streaming algorithms and Online algorithms fit into this setting. We have defined a novel model of online computation with advice, where online algorithms have some partial information about the future. We have shown the applicability of this model by giving several results for some classical online problems such as Metrical Task Systems and the k-server problem [EFKR11; RR11b]. We also gave online algorithms, and sometimes offline approximation algorithms, for various problems in communcation networks and adjacent fields [LPSR09; RR11a; RS11]. In the area of streaming algorithms, we initiated the study of memory space complexity of language recognition [MMN10] with application to large XML databases [KM12]. We have also studied graph-theoretic problems in the streaming setting, such as interval selection [EHR12] and maximum matching [KMM12]. Cryptography and Game Theory One of the other challenges brought on by the new pervasive nature of data is the question of trust. Trust can come in the form of cryptographic protocols, which ensure secrecy and authenticity, or it can come in the form of game-theoretic mechanisms that use money and utility to incentivize individuals to behave truthfully. We have studied the robustness of the computational problems underlying modern cryptography [HMX10; MX10], the optimal efficiency of various cryptographic protocols such as Zero Knowledge and bit commitment [GWXY10; Xia11b; Xia12], and the efficiency of analyzing their behavior as in computing equilibria [HRS08; MRSZ11]. We have also studied the “converse” of cryptography, relating the complexity of various models of machine learning [Xia10]. Limitations: Query and Communication Complexities We developed the study of the limitations of the models described above. The query complexity measures only the number of input bits queried for computing functions. We studied the recursive 3-majority function in this model, and provided the best-known randomized algorithm and lower bound [MNSX11]. Main other techniques are based on reduction to problems of communication complexity where information theory plays a central role as one of the new powerful techniques. We developed general methods to prove lower bounds based on Kolmogorov arguments [KL09] and information theoretical ones [KLLRX12]. Motivated by streaming algorithms applications, we also provided new lower bounds to explicit problems [IKLSW12; MMN10].

41 CHAPTER 1. RESEARCH REPORT: ALGORITHMS AND COMPLEXITY

1.1.2.2 Quantum algorithms and complexity

Quantum algorithms The main purpose of quantum computing is to design, for specific problems, faster quantum algorithms than any known classical procedure. For some class of problems the potential speedup is exponential, in other cases it is polynomial. In the former category we have conceived fast quantum algorithms for group theoretic questions, often related to the paradigmatic hidden subgroup problem [DISW11a; ISS07; ISS08a; ISS12]. For the latter case our research has concentrated on quantum query complexity of search algorithms via quantum walks. We have obtained several generic results about the quantization of classical Markov chains [KMOR10; MNRS07; MNRS09; San08], and we have applied these results to design specific algorithms for triangle [MSS07], group commutativity testing [MN07] and for constant size subgraph finding [LMS11]. We have also found a surprising application of quantum walks for Merkle puzzles [BHKKLS11a]. Communication complexity, games, non-locality The common thread in our study of communication complexity has been to study the classical and quantum models side-by-side in order to understand the similarities and differences between them. We have shown exponential gaps between classical and quantum models for the Hidden Matching problem [BJK08; GKKRW08; GKRW09]. We have also studied communication complexity from the point of view of quantum non-locality [DKLR11; KKLR11; KLLRX12; LLR12], and given upper bounds on classically simulating quantum distributions [DLR07]. We have studied the complexity of entangled games [KKMTV11; KKMV09; KRT08; KRT10; KV11] and shown hardness results on approximating the quantum value of a game. Cryptography In quantum cryptography, one of the main goals is to study the optimal security parameters for specific fundamental primitives. Moreover, it is important to extend the security proofs in realistic conditions that take into account the imperfections of the quantum devices. First, we have found the optimal parameters for coin flipping and bit commitment [CK09; CK11a] and we have studied a number of other cryptographic primitives, including oblivious transfer, zero knowledge and computational bit commitments [CCKV08; CK08; CKR11; CKS10]. Second, we have studied security in the device independent model and in the presence of losses and errors [Cha10; PCDK11; SCAKPM11].

1.2 Selected results of signiﬁcance

1.2.1 Streaming algorithms for large XML databases

In the line of our work in property testing [FMR10; MR07], we investigated streaming algorithms in the context of XML databases through several papers [CJR08; KM12; MMN10]. Below we describ two results that were presented at STOC 2010 and ICDT 2012 (best newcomer paper).

We ﬁrst addressed the problem DYCK of checking matching parentheses, with possibly different types of parenthesis [MMN10]. This problem is motivated by the concrete problem of checking well-formedness of XML ﬁles. This is also one of the simplest, but still fundamental, non-regular languages. DYCK has already been addressed in property testing, but nothing was known in the context of streaming algorithms, except for the simple case of a single type of parenthesis.√ We presented an optimal one-pass randomized streaming algorithm for DYCK with space O( n), where n is the input size. Surprisingly, the space requirement shrinks drastically to O((log n)2) if we have a second access to the input stream in reverse.

YCK n For the lower bound, we exhibited hard√ instances of D with length , that we embedded in a “one- pass” communication problem with n players. To establish the hardness of the communication problem, we proved a direct sum result using tools from information theory. The primitive instance made us revisit a standard 2-player communication complexity problem (INDEX), but√ in the completely novel point of view of asymmetric communication, and we proved that it requires Ω( n) bits of communication.

42 CHAPTER 1. RESEARCH REPORT: ALGORITHMS AND COMPLEXITY

Then, we studied the problem of validating XML documents of size n against general DTDs in the context of streaming algorithms [KM12]. Because of a reduction to some hard problem in communication complexity, streaming algorithms were known to require linear memory. Nonetheless, we showed that, when allowing access to external memory (auxiliary read/write streams), there is a deterministic streaming algorithm that solves this problem with space O(log2 n), a constant number of auxiliary read/write streams, and O(log n) number of passes.

1.2.2 Quantum cryptographic protocols

Since the discovery of unconditionally secure key distribution by Bennett and Brassard in 1984, a series of works has investigated what other cryptographic primitives are possible or not in the quantum world. Two such primitives are Coin Flipping and Bit Commitment. These primitives are fundamental since most of the cryptographic operations can be based on these primitives. In Coin Flipping, two parties must agree on a bit that is required to be 0 or 1 with equal probability. Ideally, we would like that if any party deviates from the protocol, then his cheating probability, i.e. the probability that he can force the honest player to agree on any particular outcome is no more than 1/2. It is known that ideal Coin Flipping is impossible without any hardness assumptions, in both the classical and the quantum setting. In fact, in any classical protocol, the cheating probability is always 1. However, Aharonov et al. in STOC 2000 provided a quantum protocol where no dishonest player could bias the coin with probability higher than 0.91. In STOC 2001, Ambainis described an improved protocol whose cheating probability was at most 3/4. On the other hand, Kitaev in 2003, using a formulation of quantum coin flipping protocols as semi-definite programs proved a lower bound of 1/2 on the product of the two cheating probabilities for Alice and√ Bob. In other words, no quantum coin flipping protocol can achieve√ a cheating probability less than 1/ 2 for both Alice and Bob. The question of whether 3/4 or 1/ 2 was ultimately the right bound for quantum coin flipping was finally√ resolved in our work, where we showed a quantum protocol that achieves bias arbitrarily close to 1/ 2 [CK09].

The history√ of Bit Commitment is similar but the ﬁnal answer is very different. The same gap of 3/4 versus 1/ 2 was also present for quantum bit commitment. Very recently, we proved a stronger lower bound of 0.739 for the cheating probability of any quantum bit commitment protocol, and we described a quantum protocol that achieves a cheating probability arbitrarily close to 0.739, hence providing the optimal value [CK11a].

1.3 Scientiﬁc service and inﬂuence, honors and prizes

We have a very large network of intensive scientiﬁc contacts basically all over the world. The EU Integrated Project QAP had 35 partners, the EU STREP QCS has 8 partners, and the ANR CHIST- ERA project has 6 partners. The CSQIP student training program and the STIC-Asie programme both involve 4 countries. We are co-directing with Tel-Aviv University the LEA French-Israeli Laboratory on Foundations of Computer Science (FILOFOCS), and we are a participating team in the Japanese-French UMI JFLI and in the France-Singapore LIA FSQL. We have organized and chaired the 24th IEEE Conference on Computational Complexity in 2009 in Paris. As described in Section 1.1.1, we play a key role in the GDR Informatique Mathematique´ and the GDR Information Quantique, Fondements & Applications. We are very proud of several distinctions we have received in the last few years. The “Insignes de Cheva- lier dans l’Ordre National du Merite”´ were attributed to Julia Kempe in 2011, and she has also received the prize “Femme en Or de la Recherche” in 2010. The thesis of Andre´ Chailloux has been awarded in 2011 the Gilles Kahn PhD prize. The contribution of Christian Konrad and Fred´ eric´ Magniez to the 15th International Conference on Database Theory in 2012 [KM12] has obtained the Best Newcomer Paper Award.

43 CHAPTER 1. RESEARCH REPORT: ALGORITHMS AND COMPLEXITY

1.4 Internal organization

As we have mentioned already, the team is scientifically very coherent. The basis of our arguably very good relations is our common taste and interest in scientific problems, and our similar approach towards high quality research. The other important component of these good relations is the mutual personal trust. While everybody freely selects the subject of her/his research, we naturally have numerous collaborations, and the whole output of the team turns out to be a coherent set in the field of algorithms and complexity. Of course potential new research areas are regularly discussed, and we times to times decide to invest collectively in some new domain. This happens usually when we have to deal with new contracts or with new postdocs/students. The important decisions are taken collectively. We have a weekly group meeting were all possible subjects are discussed. In case of diverging opinions we try to pursue the discussion until the emergence of an option which is agreeable for everyone. In 2012 we had six national or international projects whose total amount is 1260K euros. We are also currently applying for several new grants. We always put into each contract the largest possible subset of the team members that scientifically makes sense. We also try to distribute relatively evenly the responsibilities of the contracts, each team member has the responsibility of at least one contract in most moments of time. The contracts are mutualized in the sense that the financing of postdocs, visitors, travels, etc. by some specific contract is decided (again within the limit of scientific responsibility) at the weekly group meetings. Decisions about advising PhD students are taken individually, but of course these are also sometimes discussed collectively, especially when the student comes from an MPRI course taught by several members of the team. The choice of the postdocs is the result of a long collective process which requires the work and involvement of all team members (again, we had to choose in 2012 among more than forty applicants). Short invitations can be made by everyone. Finally, the potential arrival of new team members is discussed very seriously since it concerns the scientific orientations and the smooth functioning of the team.

44 Chapter 2

Fiche resum´ e:´ Algorithmes et Complexite´

Intitule´ de l’unite´ : LIAFA, UMR 7089 Nom du directeur de l’unite´ : Pierre Fraigniaud Nom du responsable de l’equipe´ : Miklos Santha

2.1 Effectifs

2007: 5 chercheurs CNRS, 2 enseignants-chercheurs, 1 postdoc, 6 doctorants 2012: 5 chercheurs CNRS, 2 enseignants-chercheurs, 1 postdoc, 6 doctorants Personnels qui ont quitte´ l’equipe:´ J. Kempe (on leave in 2011, 36 mois), N. Vishnoi (CR1 2008- 2009, 7 mois), 8 doctorants (288 mois), 3 postdocs (48 mois) Recrutement 2011: D. Xiao (CR2)

2.2 Production scientiﬁque

Streaming et test de propriet´ e.´ A partir de nos travaux sur le test de propriet´ e´ [FMR10; MR07], nous avons etudi´ e´ des algorithmes de streaming pour des bases de donnees´ XML dans [CJR08; KM12; MMN10]. Calcul en-ligne. Nous avons introduit un modele` nouveau de calcul en-ligne avec conseil et montre´ son utilitee´ par des resultats relatifs a des problemes` classiques, comme metrical task system et le k-server problem [EFKR11; RR11b]. NP-difficulte´ et cryptographie Nous avons etudi´ e´ la robustesse de problemes` fondamentaux en cryptographie moderne [HMX10; MX10], l’efficacit´ e´ optimale de protocoles cryptographiques non- divulguants ou de mise en gage de bit [GWXY10; Xia11b; Xia12]. Protocoles cryptographiques quantiques. Nous avons trouve´ les parametres` optimaux du tirage a` pile ou face et de la mise en gage de bit [CK09; CK11a] et avons etudi´ e´ d’autres primitives cryptographiques [CCKV08; CK08; CKR11; CKS10]. Nous avons aussi observe´ une application des marches aleatoires´ quantiques aux puzzles de Merkle [BHKKLS11a]. Marches quantiques pour des problemes` de recherche. Nous avons propose´ [MNRS07] un cadre unifie´ pour des problemes` de recherche definis´ a` partir de marches quantiques, et prouve´ [MNRS09] que le temps d’atteinte d’une marche quantique est la racine carree´ du temps d’atteinte d’une marche classique.

2.3 Bilan quantitatif

2.3.1 Publications

45 CHAPTER 2. FICHE RESUM´ E:´ ALGORITHMES ET COMPLEXITE´

[MX10] M. Mahmoody, D. Xiao. “On the power of randomized reductions and the checkability of SAT”. In: Proceeedings of 25th IEEE Conference on Computational Complexity (CCC). 2010, pp. 64–75 [CK09] A. Chailloux, I. Kerenidis. “Optimal Quantum Strong Coin Flipping”. In: Proceedings of 50th IEEE Symposium on Foundations of Computer Science (FOCS). 2009 [MNRS07] F. Magniez, A. Nayak, J. Roland, M. Santha. “Search via quantum walk”. In: Proceedings of 39th ACM Sympo- sium on Theory of Computing (STOC). 2007, pp. 575–584

2.3.2 Logiciels, brevets, rapports, etc. Habilitation a` Diriger des Recherches: 1. Fred´ eric´ Magniez, Veriﬁcation´ approchee´ – Calcul quantique, May 2007 2. Julia Kempe, Quantum Computation, September 2010 3. Iordanis Kerenidis, Interaction in the quantum world, December 2010.

2.3.3 Rayonnement

1. Prix de These` Gilles Kahn 2011 de A. Chailloux. Insignes de Chevalier dans l’Ordre National du Merite´ en 2011 et prix “Femme en Or de la Recherche” en 2010 pour J. Kempe 2. I. Kerenidis a rec¸u un “ERC Starting Independent Researcher Grant” en 2012 3. Organisation de la 24eme` Conference´ IEEE Computational Complexity en 2009 a` Paris 4. Co-direction avec l’Universite´ de Tel Aviv du LEA Laboratoire Franco-Israelien sur les fondements de l’Informatique (FILOFOCS) 5. Large reseau´ de contacts scientiﬁques intensifs: Projet Europeeen´ QAP (35 partenaires), EU STREP QCS (8 partenaires), ANR CHIST-ERA projet (6 partenaires), programme STIC-Asie (4 pays)

2.3.4 Interactions de l’equipe´ avec son environnement

1. Implication dans le GDR Informatique Mathematique´ et le GDR Information Quantique, Fonde- ments & Applications. Co-organisation avec Tel´ ecom´ Paris-Tech du groupe de travail trimestriel “Quantum Information Day in Paris” 2. Collaborations aver les entreprises Ligaran (Paris, startup sur les Ebooks) et IDQuantique (Geneve,` entreprise sur les technologies quantiques pour la communication et la securit´ e)´ 3. S. Laplante. “Le plus grand des hasards : Surprises quantiques”. In: ed. by J.-F. Dars and A. Papillaut. Belin, 2010. Chap. L’inﬂuence de l’informatique, pp. 152–154 4. Plusieurs exposes´ de vulgarisation (College` Belgique, Ens Lyon, Fondation Sciences Mathematiques´ de Paris). 5. Participation a` plusieurs projets et expositions developp´ ees´ par Sylvie Tissot d’Anabole (Paris, petite entreprise multimedia)´ sur les representations´ du calcul quantique.

2.3.5 Actions de formation

1. Masters (M2) de Paris Diderot: “Logique Mathematique´ et Fondements de l’Informatique” (1 cours) et “Master Parisien de Recherche en Informatique” (3 cours) 2. Programme d’echange´ d’edutiants´ Collaborative student training in Quantum Information Pro- cessing entre l’ Europe (3 pays) et le Canada 3. “Ecole des Jeunes Chercheurs en Informatique Mathematique”´ (2009, co-organisation) et “Ecole de Printemps d’Informatique Theorique”´ (2012, organisation) 4. Participation a` 2 ecoles´ thematiques´ sur l’informatique quantique a` Montreal´ (2010)

46 Chapter 3

Executive Summary: Algorithms and Complexity

Laboratory’s name: LIAFA, UMR 7089 Laboratory director’s name: Pierre Fraigniaud Team leader’s name: Miklos Santha

3.1 Members

2007: 5 CNRS researcher, 2 faculty members, 1 postdoc, 6 PhD students 2012: 5 CNRS researcher, 2 faculty members, 1 postdoc, 6 PhD students Permanent members who left the team: J. Kempe (on leave in 2011, 36 month), N. Vishnoi (CR1 2008-2009, 7 months), 8 PhD students (288 months), 3 postdocs (48 months) Hiring in 2011: D. Xiao (CR2) 3.2 Scientiﬁc outcomes

Streaming algorithms and Property Testing. In the line of our work in property testing [FMR10; MR07], we investigated streaming algorithms in the context of XML databases in several papers [CJR08; KM12; MMN10]. Online computation. We have defined a novel model for online computation with advice and have shown its applicability for some classical online problems such as metrical task systems and the k-server problem [EFKR11; RR11b]. NP-hardness and cryptography We have studied the robustness of computational problems underlying modern cryptography [HMX10; MX10], the optimal efficiency of cryptographic protocols such as zero-knowledge and bit commitment [GWXY10; Xia11b; Xia12]. Quantum cryptographic protocols. We have found the optimal parameters for coin flipping and bit commitment [CK09; CK11a] and we have studied a number of other cryptographic primitives [CCKV08; CK08; CKR11; CKS10]. We have also found a surprising application of quantum walks for Merkle puzzles [BHKKLS11a]. Quantum walks for search problems. We provided [MNRS07] a unified and simple framework for designing search algorithms via quantum walks, and proved [MNRS09] that the quantum hitting time of a random walk is the square root of its classical hitting time. 3.3 Quantitative assessment

3.3.1 Publications

[MMN10] F. Magniez, C. Mathieu, A. Nayak. “Recognizing well-parenthesized expressions in the streaming model”. In: Proceedings of 42nd ACM Symposium on Theory of Computing (STOC). 2010, pp. 261–270 [EFKR09b] Y. Emek, P. Fraigniaud, A. Korman, A. Rosen.´ “Online Computation with Advice”. In: Proceedings of 36th International Colloquium on Automata, Languages and Programming (ICALP). 2009, pp. 427–438 [MX10] M. Mahmoody, D. Xiao. “On the power of randomized reductions and the checkability of SAT”. In: Proceeedings of 25th IEEE Conference on Computational Complexity (CCC). 2010, pp. 64–75

47 CHAPTER 3. EXECUTIVE SUMMARY: ALGORITHMS AND COMPLEXITY

[CK09] A. Chailloux, I. Kerenidis. “Optimal Quantum Strong Coin Flipping”. In: Proceedings of 50th IEEE Symposium on Foundations of Computer Science (FOCS). 2009 [MNRS07] F. Magniez, A. Nayak, J. Roland, M. Santha. “Search via quantum walk”. In: Proceedings of 39th ACM Sympo- sium on Theory of Computing (STOC). 2007, pp. 575–584

3.3.2 Software, patents, reports, etc. Habilitation a` Diriger des Recherches: 1. Fred´ eric´ Magniez, Veriﬁcation´ approchee´ – Calcul quantique, May 2007 2. Julia Kempe, Quantum Computation, September 2010 3. Iordanis Kerenidis, Interaction in the quantum world, December 2010.

3.3.3 Inﬂuence of the team

1. Gilles Kahn PhD prize in 2011 for the thesis of A. Chailloux. “Insignes de Chevalier dans l’Ordre National du Merite”´ in 2011 and prize “Femme en Or de la Recherche” in 2010 to J. Kempe. 2. I. Kerenidis has obtained an ERC Starting Independent Researcher Grant in 2012 3. Organization of the 24th IEEE Conference on Computational Complexity in 2009 in Paris 4. Co-direction with Tel Aviv University of the LEA French-Israeli Laboratory on Foundations of Computer Science (FILOFOCS) 5. Very large international network of intensive scientiﬁc contacts: EU Integrated Project QAP (35 partners), EU STREP QCS (8 partners), ANR CHIST-ERA project (6 partners), STIC-Asie program (4 countries)

3.3.4 Interactions between the team and its environment

1. Key role in the GDR Informatique Mathematique´ and the GDR Information Quantique, Fonde- ments & Applications. Co-organization with Tel´ ecom´ Paris-Tech of the trimestrial workshop “Quantum Information Day in Paris” 2. Collaborations with the companies Ligaran (Paris, startup on Ebooks) and IDQuantique (Geneva, company on quantum technologies for communication and security) 3. S. Laplante. “Le plus grand des hasards : Surprises quantiques”. In: ed. by J.-F. Dars and A. Papillaut. Belin, 2010. Chap. L’inﬂuence de l’informatique, pp. 152–154 4. Several popularization talks (College` Belgique, Ens Lyon, Fondation Sciences Mathematiques´ de Paris). 5. Participation to several projects and expositions developed by Sylvie Tissot from Anabole (Paris, small multimedia company) on representations of quantum computing.

3.3.5 Teaching

1. Master programs (M2) of Paris Diderot: “Logique Mathematique´ et Fondements de l’Informatique” (1 course) and “Master Parisien de Recherche en Informatique” (3 courses) 2. Student exchange program Collaborative student training in Quantum Information Processing between Europe (3 countries) and Canada 3. “Ecole des Jeunes Chercheurs en Informatique Mathematique”´ (2009, co-organization) and “Ecole de Printemps d’Informatique Theorique”´ (2012, organization) 4. Participation to 2 advanced schools in quantum information processing at Montreal (2010)

48 Chapter 4

Research project: Algorithms and Complexity

4.1 Research objectives

4.1.1 Scientiﬁc outlook

Massive data There is already an explosion in the size of the data that algorithms are called upon to process in everyday real time applications. Examples of such applications occur in bioinformatics for genome decoding, in Web databases for the search of documents, or in network monitoring. More advanced settings involve graph structured data such as biological or social networks, E-R schema, work flows and the Web. Recent network applications use streams defined over the massive graph infrastructure. For example, the graph vertices represent web pages or IP addresses, and the edges represent links between web pages or communication activities among IP addresses. This proliferation of massive data sets brings with it its own set of special computational challenges. The standard view of computing puts the spotlight on the output rather than on the input. Traditionally, limited computational resources are leveraged by lowering expectations about the quality of the output, resorting to, for example, approximation algorithms (producing a sub-optimal output) or randomized Monte Carlo algorithms (producing a not necessarily correct output). However, with the “data avalanche” that arises in a wide range of scientific and commercial applications, dwarfing anything seen before, that standard view is not sufficient to capture the quantity and widely distributed nature of data now being gathered by diverse institutions and individuals. With such changes of scale, and with indirect access to input that might not be “truthfully” reported, new structures are built, and there is a clear need for different models. This social behavior explains the shift in focus toward the input, prompting new questions in algorithmic design and computational complexity. Thus some areas have gained increased prominence, sometimes greatly so: sub-linear algorithms, property testing, streaming algorithms, online computing, distributed computing, and algorithmic game theory. In most of those areas, the goal is to study some notion of restricted data access, modeled with an appropriate notion of complexity. Then algorithms are designed, giving a trade-off between traditional time and space complexity on the one hand, and data access complexity on the other hand. Of course this complements rather than replaces old paradigms: to fight intractability in the new settings, approximation and randomization still come into play.

Quantum information area - Hybrid network Quantum Information Processing has the potential to revolutionize the future of information technologies. A tremendous research effort by computer scientists, physicists, mathematicians, engineers, has been put into addressing each of the major challenges in the area, from quantum algorithms and complexity to quantum cryptography, to large-scale realizations of quantum computers, to error correction. Shor’s algorithm for factoring shows that quantum computers are probably more powerful than classical ones and moreover that most currently used classical cryptographic systems, such as RSA, are vulnerable against quantum computers. In addition, the ability

49 CHAPTER 4. RESEARCH PROJECT: ALGORITHMS AND COMPLEXITY to communicate over quantum channels has made it possible to revisit unconditionally secure cryptography. In one of the most celebrated results in quantum computation, Bennett and Brassard showed that it is possible for two parties to distribute a secret key in a way that is unconditionally secure against all attacks. We note that there have been real implementations of key distribution over hundreds of kilometers. Our long-term vision of the quantum information era is a network of quantum and classical devices, where individual agents have the ability to communicate efficiently in a variety of ways with trusted and untrusted parties and securely delegate computational tasks to a number of untrusted large-scale quantum computing servers. In such an interconnected world, the notion of security is an imperative. When one is concerned with the notion of security, it is wise to build systems that are secure not only against current adversaries, but also against future malicious parties with ever more sophisticated computational abilities, in particular adversaries with the ability to perform quantum computations and hence break most currently used cryptosystems. It is, therefore, an urgency to strengthen the foundations of cryptography, in order to make them adequate for a quantum world. Moreover, it is necessary that the interaction between agents remains efficient and takes advantage of the power of quantum information that can drastically reduce the communication overhead for several distributed computational problems. In order to guarantee the viability and robustness of the network it is also important to provide the agents with incentives for honest behavior. The realization of such a complex network of classical and quantum communication must rely on a solid theoretical foundation that nevertheless is able to foresee and handle the intricacies of real-life implementations. The study of security and efficiency of quantum communications is inherently related to the fundamental notions of quantum mechanics, including entanglement and non-locality, as well as to central notions in classical complexity theory and cryptography.

4.1.2 Our long term scientiﬁc goals: Efﬁciency and Security

The first challenge we will address is how to guarantee efficiency in the novel computational models that arise from the need of manipulating massive data and from the existence of hybrid classical-quantum networks. Indeed, the very notion of “efficient” has evolved since the early days of computer science, where it typically meant polynomial time. Today, “efficient” algorithms must often work in logarithmic space (as is often the case in streaming), make decisions without seeing the entire input (as in online algorithms), only see a small constant number of bits of the input (as in property testing), or not see the true input but only what agents report (as in algorithmic game theory). “Efficiency” also means different things in quantum settings, where we seek to build algorithms and protocols that are exponentially faster than their classical counterparts. Our goal is to build classical and quantum algorithms and protocols that are efficient and will be essential components of the future information era. The second challenge we will address is how to guarantee security in the future information era. The integration of computation into more areas of our lives has raised the concern that our data may be misused or leaked. Embarrassing accidents where private user information is leaked are alarmingly common, such as when Sony inadvertently lost its users’ credit card information, or when Apple was revealed to be secretly logging users’ location data on their iPhones. Our goal is to develop cryptography and privacy techniques that are able to protect against such violations, hence maintaining confidence in the information infrastructure and promoting the continued growth of online economic activity. More- over, we would like to look at security against any future adversary, including ones that may possess quantum computers.

50 CHAPTER 4. RESEARCH PROJECT: ALGORITHMS AND COMPLEXITY

4.1.3 Detailed descriptoin of research objectives

In order to achieve our aforementioned long term goals we will proceed by working on three main axes: Restricted Data Access, Uncertainty and Development of Tools. Each axis is subdivided in a number of tasks that will be pursued in parallel. All members of the group will work in several such tasks in collaboration with each other and with other researchers in France and internationally.

4.1.3.1 Restricted data access

Query complexity Even relatively simple functions are poorly understood from the point of view of query complexity. One function that has been widely studied is the recursive majority of 3 functions. We gave the best currently-known upper and lower bounds for this function [MNSX11], but these bounds still not match. We will explore further directions by looking at different strategies to improve the bounds. Quantum query complexity is a well established ﬁeld on his own. We plan to continue working on the potential applications of quantum walks. In a recent work Belovs has proposed an alternative approach to construct quantum algorithms using the computational model of a learning graph. While learning graphs can simulate all known quantum walk based algorithms, it is an open problem if the inverse simulation is possible. We propose to study in depth the computational power of learning graphs, and their relationship with quantum walks. Property testing In property testing, we would like to have a better understanding on the dependence between the complexity and the approximation parameter. For practical considerations, this dependence can be at most polynomial, whereas it is often exponential, such as in our previous work on Markov Decision Processes (MDPs) [RT09]. In the context of quantum computing, property testing can be generalized in two directions either by allowing quantum algorithms or by considering the (classical) test of quantum devices. We contributed and plan to pursue to both directions [DMMS07; FMSS09]. The second one is of practical importance. In a near future, one will buy quantum devices, at least for cryptographic settings. We want to design simple experiments that ensure the correctness of those equipments. Streaming algorithms We initiated the study of the space complexity for deciding membership to a given language, when only sequential access to input is allowed [KM12; MMN10]. But still very little is known here, especially when the number of passes (and their directions), and (constant) number of auxiliary read/write streams are parameters. We will pursue our study in order to understand and characterize this new hierarchy. We are also interested in graph semi-streaming algorithms, in which the available memory is roughly linear in the number of vertices. Flows are a family of problems that are pervasive in network applications. We have started studying maximum cardinality matching [KMM12], a special case of ﬂows. We are also interested graph theoretic problems such as dominant set or independent set, for which we obtained tight results in the case of sets of intervals [EHR12]. Online algorithms In online algorithms we plan to study, and quantify, the impact of partial information about the future on the performance of the online algorithm, using the model of online compitation with advice that we have introduced [EFKR11]. We plan to revisit classical online problems, as well as to study new problems, and to give upper and lower bounds on the attainable competitive ratio in terms of the number of bits of information about the future that the online algorithm receives together with each request.

51 CHAPTER 4. RESEARCH PROJECT: ALGORITHMS AND COMPLEXITY

4.1.3.2 Uncertainty

Complexity of cryptography In cryptography, we will aim to make the security of cryptographic systems stronger by studying the possibility of building secure cryptography based on NP-hard problems. In previous work, we provided evidence that there are formal reasons why this goal may be unattain- able [HMX10; MX10], and we will seek to extend our previous work for example by studying the related question of how efficient one can possibly make proofs for UNSAT (the complement of SAT). Another goal in cryptography is to make cryptographic systems as efficient as possible for the honest users. Extending our previous work [GWXY10; Xia11b; Xia12], we will also seek to optimize the efficiency of cryptographic protocols such as zero knowledge proofs and commitment schemes. In quantum cryptography, we will seek to provide optimal protocols for some fundamental cryptographic primitives, including oblivious transfer and zero knowledge. Differential privacy Differential privacy is a rigorous notion of privacy, which states that the output of an analysis of some database should not reveal too much information about any individual whose data appears in the database. In continuing ongoing work [Xia11a], we will look at the tradeoffs possible between differential privacy and accuracy of the output data, incentives that surround differential privacy, and we will also look at multi-party computation protocols for achieving differential privacy. Security in realistic conditions We will extend our security proofs of quantum cryptographic primitives to realistic conditions in order to guarantee security of real life implementations of such primitives with current technology. In addition we will construct protocols for verifying the correctness of quantum devices. Algorithmic Game Theory Classical Game theory studies the interaction of many players who take independent decisions. Natural notions of Equilibria have been introduced in the 1960s and Algorith- mic Game theory studies the complexity of these problems and the possible algorithms to reach such Equilibria. These problems are in NP and coNP, and the complexity classes PLS and PPAD have been introduced to capture their exact complexity. We study approximate algorithms for Nash Equilibria for specific classes of games, such as Congestion games [MRSZ11], and fast dynamics which may lead to such approximate Equilibria. Quantum Mechanics through a cryptographic lens We would like to understand fundamental notions of quantum mechanics, including entanglement and non-locality, by looking at them through a cryptographic lens. More precisely, can we unify the fundamental constants that appear on one hand, in Bell inequality violations, and on the other hand, as the optimal parameters of coin flipping and bit commitment.

4.1.3.3 Development of Tools

Quantum techniques from quantum nonlocality Since quantum communication is more powerful than classical communication, quantum lower bounds often require new techniques. Some of the stronger techniques in communication complexity apply to classical communication only. We would like to extend these techniques to the quantum case, by using our understanding of quantum non-locality. We also would like to show some gaps between the classical and quantum methods, in order to understand the difference between classical and quantum phenomena. Direct sum theorems Another central question in communication complexity is the direct sum question: given a function f with communication complexity C, how much communication is necessary to n f compute independent copies of ? This question remains open for the case of√ randomized communication complexity; the best known results of Barak et al. shows that roughly Ω( nC) communication is necessary. As was shown by Braverman and Rao, an inherently related question is whether communication can be compressed. We propose to study these questions by applying tools from various areas

52 CHAPTER 4. RESEARCH PROJECT: ALGORITHMS AND COMPLEXITY of computer science, including information theory and quantum techniques. Furthermore we will seek to apply any tools developed in the study of direct sums and compressing interactive communication to the study of streaming algorithms and other limited-data-access models. Duality of communication and queries The adversary method in quantum query complexity has been shown to be optimal. Lee et a have shown that the adversay method, in its dual formulation, coincides with a generalization of the factorization norm method of Linial and Schraibman, a lower bound for communication complexity. We would like to understand the underpinnings of this result, and see whether this might lead to optimal bounds in quantum communication complexity as a result. These results apply to quantum complexity, and a second goal is to prove analogous results for classical query versus communication complexity.

4.2 Project implementation

Positioning and SWOT analysis (see Figure 4.1) We consider that in the last few years we have successfully identified the new scientific challenges in information and communication technologies presented by the arrival of problems on massive data set, the related privacy and security consideration, and the prospect of unconventional models of computing. We believe that these challenges hold a tremendous research opportunity, and since they are interconnected, the only way to successfully address them is to address them simultaneously. The potential threat we can see for a research team in this new context is that it is not able to identify clearly the relevant problems it has to address, or that it lacks in competence to do that, and therefore falls behind its competitors. We think that our double competence in classical and quantum computing is our greatest strength. It is a quite unique characteristic, and it gives us considerable advantage for tackling new scientific issues. Our highest priority is excellence. We are confident that in the field of quantum information theory we will keep our leadership position in quantum computing, complexity, communication and cryptography. If the opportunity presents itself, we would like to secure our strengths in quantum games and interaction. In classical algorithmic we very consciously focus our work more and more on input driven computing, and we had already some important achievements in property testing, online and streaming algorithms. The recent arrival of David Xiao has considerably reinforced our competences in security. Still, we feel a relative weakness here in the sense that while our international research status is good in classical computing, it is not at the same level as our position in quantum computing. We will try to use, whenever possible and reasonable, a unified approach involving classical and quantum computing. Such a simultaneous approach to algorithmic problems often inspires concepts and solutions that otherwise most likely would not have been invented or found. Also, our team is very coherent and we regularly update each other about the latest results in our respective specialities. In consequence we believe that we can successfully meet the challenge of rightly identifying worthy research subjects and exploiting new opportunities. To raise further our quality in classical computing we intend to make the highest profit of our national and international collaborations where our partners have relevant competences. We will also pursue our dynamic postdoc hiring procedure which was rather successful in 2012.

Partnerships We have a very wide network of international collaborations some of which go back to more than 20 years. The list of our partners in our current international projects include the following institutions: University of Latvia Riga, University of Bristol, CWI Amsterdam, Tel Aviv University, Universite´ Libre de Bruxelles, Institute of Photonic Sciences Barcelona, University of Cambridge, Uni- versite´ de Geneve,` University of London Royal Holloway, Chinese University of Hong Kong, National University of Singapore, Tata Institute of Fundamental Research Mumbai. Our partners in the three CNRS international research unit we participate in are: University of Tokyo, National Institute of Infor- matics, Keio University, Centre for Quantum Technologies Singapore and Tel Aviv University. We also

53 CHAPTER 4. RESEARCH PROJECT: ALGORITHMS AND COMPLEXITY plan to maintain strong links in the future with the following institutions in North America: UC Berke- ley, Rutgers University, Institute for Advanced Study Princeton, Universite´ de Montreal,´ University of Waterloo. The partners in our current national projects are Tel´ ecom´ ParisTech and LIP6 at the Universite´ Pierre et Marie Curie. Other teams we would like to collaborate with in the future include the LIENS at ENS Ulm. With the LIENS we are organizing a joint crypto-complexity workshop in June 2012 which features talks about topics that may lead to further collaboration between the groups. In LIAFA we have the strongest link with the “Distributed Algorithms and Graphs” team: we regularly attend each other’s seminar, we started a project on non local correlations, and we will share a course in the MPRI. We are currently applying for three joint research projects. Our 4 years ANR BLANC proposal “Al- gorithmic Techniques for Restricted Data Access Models” (RDAM) is jointly filed with the LIENS. Here we plan to complete our competence in randomized and quantum computing with the competence of the LIENS in approximation algorithms. Our second proposal “Managing Uncertainty in Informat- ics” (MUNI) is in collaboration with the Institute for Interdisciplinary Information Sciences (IIIS) at Tsinghua University, Beijing. It is between the ANR (BLANC International) and the National Natural Science Foundation of China, and its prospective length is is also 4 years. The purpose of the project is to build deeper collaborations in questions related to the handling of uncertainty, such as noise in data analysis and machine learning, and secure computing in an adversarial environment. Our third proposal is a STREP in the framework of the FET Proactive Initiative in Quantum Information Communication and Technologies. The 3 years project “Quantum Algorithmics” (QALGO) next to LIAFA brings together research institutes from Latvia, the UK, the Netherlands, Belgium, Israel and Germany. Its main goal is to find new algorithms for quantum computers and new quantum communication protocols that are more efficient than the classical ones. Very recently we have learnt that the first and the third proposal have been accepted, we don’t know yet the result of the second application. Finally we mention that David Xiao is participating in a proposal for the ANR JCJC led by Damien Vergniaud at ENS, which will study the role of randomness in cryptography.

Funding We invest considerable energy to secure adequate funding for achieving our scientific goals. These include maintaining scientific contacts, hiring high quality postdocs and attending international conferences The total amount we dispose of in our current projects is 1260K euros, and the requested financing in the projects we are applying for is 950K euros.

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INTERNAL

• research status in classical computing not • as high as in quantum small team size

double competence • in classical and quantum computing Weakness leadership position • in quantum computing recent arrival of D. Xiao

• Strength NEGATIVE S W O T POSITIVE • Opportunity new research areas: quantum games, interaction and • input driven computing Threat numerous international • collaborations postdoc hiring

keeping up with • new challenges in ICT competitors •

EXTERNAL

Figure 4.1: SWOT analysis of the scientiﬁc project

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56 Chapter 5

List of publications: Algorithms and Complexity

ACL : Articles in international or national journals

Publications [EFKR10; EFKR11] are joint with team ”Distributed algorithms and graphs”.

[AGIK09] D. Aharonov, D. Gottesman, S. Irani, J. Kempe. “The Power of Quantum Systems on a Line”. Communications in Mathematical Physics 287.1 (2009), pp. 41–65. [AKLLRD07] D. Aharonov, J. Kempe, Z. Landau, S. Lloyd, O. Regev, W. van Dam. “Adiabatic Quan- tum Computation is Equivalent to Standard Quantum Computation”. SIAM Journal on Computing 37.1 (2007), pp. 166–194. [BBLR10b] L. Becchetti, I. Bordino, S. Leonardi, A. Rosen.´ “Fully decentralized computation of aggregates over data streams”. SIGKDD Explorations 12.2 (2010), pp. 83–91. [BJK08] Z. Bar-Yossef, T. Jayram, I. Kerenidis. “Exponential separation of quantum and classical one-way communication complexity”. SIAM Journal on Computing 38.1 (2008), pp. 366– 384. [CKLR11] P. Carmi, M. Katz, Z. Lotker, A. Rosen.´ “Connectivity guarantees for wireless networks with directional antennas”. Computational Geometry 44.9 (2011), pp. 477–485. [DKLR11] J. Degorre, M. Kaplan, S. Laplante, J. Roland. “The communication complexity of non- signaling distributions”. Quantum Information and Computation 11.8 (2011), pp. 649– 676. [DKTV12] S. Datta, R. Kulkarni, R. Tewari, N. Vinodchandran. “Space complexity of Bipartite Matching on bounded genus graphs”. Journal of Computer and System Science 78.3 (2012), pp. 765–779. [DLR07] J. Degorre, S. Laplante, J. Roland. “Simulation of bipartite qudit correlations”. Physical Review A 75.1 (2007), p. 012309. [DMMS07] W. van Dam, F. Magniez, M. Mosca, M. Santha. “Self-testing of universal and fault- tolerant sets of quantum gates”. SIAM Journal on Computing 37.2 (2007), pp. 611–629. [EFKR10] Y. Emek, P. Fraigniaud, A. Korman, A. Rosen.´ “On the additive constant of the k-server Work Function Algorithm”. Information Processing Letters 110.24 (2010), pp. 1120–1123. [EFKR11] Y. Emek, P. Fraigniaud, A. Korman, A. Rosen.´ “Online Computation with Advice”. Theo- retical Computer Science 412.24 (2011). Special issue of ICALP’09, pp. 2642–2656. [FISV09] K. Friedl, G. Ivanyos, M. Santha, Y. Verhoeven. “On the Black-Box Complexity of Sperner’s Lemma”. Theory of Computing Systems 45.3 (2009), pp. 629–646. [FMR10] E. Fischer, F. Magniez, M. de Rougemont. “Approximate Satisﬁability and Equivalence”. SIAM Journal on Computing 39.6 (2010), pp. 2251–2281.

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[FMSS09] K. Friedl, F. Magniez, M. Santha, P. Sen. “Quantum testers for hidden group properties”. Fundamenta Matematicae 91.2 (2009). Special issue on Machines on Computations and Universality, pp. 325–340. [GKKRW08] D. Gavinsky, J. Kempe, I. Kerenidis, R. Raz, R. de Wolf. “Exponential Separation for One-Way Quantum Communication Complexity, with Applications to Cryptography”. SIAM Journal on Computing 38.5 (2008), pp. 1695–1708. [GKRW09] D. Gavinsky, J. Kempe, O. Regev, R. de Wolf. “Bounded-Error Quantum State Identi- fication and Exponential Separations in Communication Complexity”. SIAM Journal on Computing 39.1 (2009), pp. 1–24. [GR10] E. Gordon, A. Rosen.´ “Competitive Weighted Throughput Analysis of Greedy Protocols on DAGs”. ACM Transactions on Algorithms 6.3 (2010). [HKP11] P. Hatami, R. Kulkarni, D. Pankratov. “Varations on the sensitivity conjecture”. Theory of Computing, Graduate Surveys 4 (2011). [ISS12] G. Ivanyos, L. Sanselme, M. Santha. “An efficient quantum algorithm for the hidden subgroup problem in nil-2 groups”. Algorithmica 62.1-2 (2012), pp. 480–498. [JKS10] R. Jain, H. Klauck, M. Santha. “Optimal direct sum results for deterministic and randomized decision tree complexity”. Information Processing Letters 110.20 (2010), pp. 893– 897. [Ker09] I. Kerenidis. “Quantum multiparty communication complexity and circuit lower bounds”. Mathematical Structures in Computer Science 19.1 (2009). Special issue for TAMC’07, pp. 119–132. [KK07] E. Kashefi, I. Kerenidis. “Statistical Zero Knowledge and quantum one-way functions”. Theoretical Computer Science 378.1 (2007), pp. 101–116. [KKLR11] M. Kaplan, I. Kerenidis, S. Laplante, J. Roland. “Non-Local Box Complexity and Secure Function Evaluation”. Quantum Information and Computation 11.1 (2011), pp. 40–69. [KKMTV11] J. Kempe, H. Kobayashi, K. Matsumoto, B. Toner, T. Vidick. “Entangled games are hard to approximate”. SIAM Journal on Computing 40.3 (2011), pp. 848–877. [KKMV09] J. Kempe, H. Kobayashi, K. Matsumoto, T. Vidick. “Using Entanglement in Quantum Multi-Prover Interactive Proofs”. Computational Complexity 18.2 (2009), pp. 273–307. [KL11] M. Kaplan, S. Laplante. “Kolmogorov complexity and combinatorial methods in communication complexity”. Theoretical Computer Science 412.23 (2011). Special issue of TAMC’09, pp. 2524–2535. [Kon11] C. Konrad. “Two-constraint domain decomposition with Space Filling Curves”. Parallel Computing 37 (4-5 2011), pp. 203–216. [KPS07] J. Kempe, L. Pyber, A. Shalev. “Permutation groups, minimal degrees and quantum computing”. Groups, Geometry, and Dynamics 1.4 (2007), pp. 553–584. [KR08] A. Kesselman, A. Rosen.´ “Controlling CIOQ Switches with Priority Queuing and in Mul- tistage Interconnection Networks”. Journal of Interconnection Networks 9.1/2 (2008), pp. 53–72. [KRT10] J. Kempe, O. Regev, B. Toner. “Unique Games with Entangled Provers are Easy”. SIAM Journal on Computing 39.7 (2010), pp. 3207–3229. [Kul11] R. Kulkarni. “On the power of isolation in planar graphs”. ACM Transactions on Compu- tation Theory 3.1 (2011).

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[KW12] I. Kerenidis, S. Wehner. “Long distance two-party quantum crypto made simple”. Quan- tum Information and Computation 12 (5 2012), pp. 448–460. [LLMRP07] S. Laplante, R. Lassaigne, F. Magniez, M. de Rougemont, S. Peyronnet. “Probabilistic abstraction for model checking: An approach based on property testing”. ACM Transaction on Computational Logic 8.4 (2007), p. 20. [LM08] S. Laplante, F. Magniez. “Lower bounds for randomized and quantum query complexity using Kolmogorov arguments”. SIAM Journal on Computing 38.1 (2008), pp. 46–62. [LPSR09] Z. Lotker, B. Patt-Shamir, A. Rosen.´ “Distributed Approximate Matching”. SIAM Journal on Computing 39.2 (2009), pp. 445–460. [MMLC10] L. Magnin, F. Magniez, A. Leverrier, N. Cerf. “Strong No-Go Theorem for Gaussian Quantum Bit Commitment”. Physical Review A 81.1 (2010), 010302(R). [MN07] F. Magniez, A. Nayak. “Quantum Complexity of Testing Group Commutativity”. Algo- rithmica 48.3 (2007), pp. 221–232. [MNRS11] F. Magniez, A. Nayak, J. Roland, M. Santha. “Search via quantum walk”. SIAM Journal on Computing 40.1 (2011), pp. 142–164. [MNRS12] F. Magniez, A. Nayak, P. Richter, M. Santha. “On the hitting times of quantum versus random walks”. Algorithmica 63.1 (2012), pp. 91–116. [MR07] F. Magniez, M. de Rougemont. “Property testing of regular tree languages”. Algorithmica 49.2 (2007), pp. 127–146. [MSS07] F. Magniez, M. Santha, M. Szegedy. “Quantum Algorithms for the Triangle Problem”. SIAM Journal on Computing 37.2 (2007), pp. 413–424. [NRS10] J. Naor, A. Rosen,´ G. Scalosub. “Online Time-Constrained Scheduling in Linear and Ring Networks”. Journal of Discrete Algorithms 8.4 (2010), pp. 346–355. [PCDK11] A. Pappa, A. Chailloux, E. Diamanti, I. Kerenidis. “Practical quantum coin ﬂipping”. Physical Review A 84 (5 2011), p. 052305. [PCWDK12a] A. Pappa, A. Chailloux, S. Wehner, E. Diamanti, I. Kerenidis. “Multiparty entanglement veriﬁcation resistant against dishonest parties”. Physical Review Letters (2012). [Ric07a] P. Richter. “Almost uniform sampling via quantum walks”. New Journal of Physics 9 (2007), p. 72. [Ric07b] P. Richter. “Quantum speedup of classical mixing processes”. Physical Review A 76 (2007), p. 042306. [RR11a]H.R acke,¨ A. Rosen.´ “Approximation Algorithms for Time-Constrained Scheduling on Line Networks”. Theory of Computing Systems 49.4 (2011). Special issue of SPAA’09, pp. 834–856. [RS11] A. Rosen,´ G. Scalosub. “Rate vs. Buffer Size - Greedy Information Gathering on the Line”. ACM Transactions on Algorithms 7.3 (2011). [RV08] M. de Rougemont, A. Vieilleribiere.` “Approximate Schemas, Source-Consistency and Query Answering”. International Journal on Intelligent Database Systems 31.2 (2008), pp. 127–146. [SCAKPM11] J. Silman, A. Chailloux, N. Aharon, I. Kerenidis, S. Pironio, S. Massar. “Fully Distrust- ful Quantum Bit Commitment and Coin Flipping”. Physical Review Letters 106.220501 (2011).

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[SMGPC07] J. Sudjana, L. Magnin, R. Garc´ıa-Patron,´ N. Cerf. “Tight bounds on the eavesdropping of a continuous-variable quantum cryptographic protocol with no basis switching”. Physical Review A 76 (2007), p. 052301. [SS09] M. Santha, M. Szegedy. “Quantum and classical query complexities of local search are polynomially related”. Algorithmica 55.3 (2009), pp. 557–575.

C-INV : Invited talks

[Ker07a] I. Kerenidis. “Introduction to Quantum Information Theory”. In: 2nd International Con- ference on Information Theoretic Security. Vol. 4883. 2007, pp. 146–147. [Lap07] S. Laplante. “Quantum vs Classical Theories: Simulating Quantum Correlations with Clas- sical Resources”. In: 3rd Computability in Europe. 2007. [Mag10] F. Magniez. “Application of Phase Estimation in Quantum Walks”. In: 5th Conference on the Theory of Quantum Computation, Communication and Cryptography. 2010. [San08] M. Santha. “Quantum Walk Based Search Algorithms”. In: Proceedings of 5th Interna- tional Conference on Theory and Applications of Models of Computation. 2008, pp. 31– 46. [San09] M. Santha. “Quantum Walk Based Search Algorithms”. In: 4th Conference on the Theory of Quantum Computation, Communication and Cryptography. 2009. [San10] M. Santha. “Quantization of random walks: Search algorithms and hitting time”. In: Pro- ceedings of 5th International Computer Science Symposium in Russia (CSR). 2010, p. 343. [Xia11c] D. Xiao. “Pseudo-alea:´ objets et gen´ eration”.´ In: Journees´ annuelles de la SMF. 2011.

C-ACTI : International conference proceedings

Publications [EFKR09a; EFKR09b] are joint with team ”Distributed algorithms and graphs”.

[AGIK07] D. Aharonov, D. Gottesman, S. Irani, J. Kempe. “The Power of Quantum Systems on a Line”. In: Proceedings of 48th IEEE Symposium on Foundations of Computer Science (FOCS). 2007, pp. 373–383. [AKS10] A. Ambainis, J. Kempe, O. Sattath. “A quantum Lovasz´ Local Lemma”. In: Proceedings of 42nd ACM Symposium on Theory of Computing (STOC). 2010, pp. 151–160. [ALPS07] L. Antunes, S. Laplante, A. Pinto, L. Salvador. “Cryptographic security of individual instances”. In: Proceedings of 1st International Conference on Information Theoretic Secu- rity. 2007, pp. 195–210. [AMRR11] A. Ambainis, L. Magnin, M. Roetteler, J. Roland. “Symmetry-assisted adversaries for quantum state generation”. In: Proceedings of 26th IEEE Conference on Computational Complexity (CCC). 2011, pp. 167–177. [BBLR10a] L. Becchetti, I. Bordino, S. Leonardi, A. Rosen.´ “Fully Decentralized Computation of Aggregates over Data Streams”. In: Proceedings of 1st International Workshop on Novel Data Stream Pattern Mining Techniques. 2010, pp. 1–9. [BHKKLS11a] G. Brassard, P. Høyer, K. Kalach, M. Kaplan, S. Laplante, L. Salvail. “Merkle puzzles in a quantum world”. In: Proceedings of 31st International Conference on Cryptology (CRYPTO). 2011, pp. 385–404. [CCKV08] A. Chailloux, D. Florin Ciocan, I. Kerenidis, S. Vadhan. “Interactive and Noninteractive Zero Knowledge are Equivalent in the Help Model”. In: Proceedings of 5th Theory of Cryptography Conference (TCC). 2008, pp. 501–534.

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[Cha10] A. Chailloux. “Improved loss tolerant quantum coin ﬂipping”. In: Proceedings of 10th Asian Conference on Quantum Information Science. 2010. [CJR08] H. Cheng, L. Jun, M. de Rougemont. “Approximate validity of XML Streaming Data”. In: Proceedings of 9th International Conference on Web-age Information Management. 2008, pp. 149–156. [CK08] A. Chailloux, I. Kerenidis. “Increasing the Power of the Veriﬁer in Quantum Zero Knowl- edge”. In: Proceedings of 28th Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS). 2008, pp. 95–106. [CK09] A. Chailloux, I. Kerenidis. “Optimal Quantum Strong Coin Flipping”. In: Proceedings of 50th IEEE Symposium on Foundations of Computer Science (FOCS). 2009. [CK11a] A. Chailloux, I. Kerenidis. “Optimal bounds for quantum bit commitment”. In: Proceed- ings of 52nd IEEE Symposium on Foundations of Computer Science (FOCS). 2011, pp. 354–362. [CKR11] A. Chailloux, I. Kerenidis, B. Rosgen. “Quantum Commitments from Complexity As- sumptions”. In: Proceedings of 38th International Colloquium on Automata, Languages and Programming (ICALP). 2011, pp. 73–85. [CKS10] A. Chailloux, I. Kerenidis, J. Sikora. “Lower bounds for Quantum Oblivious Transfer”. In: Proceedings of 30th Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS). 2010, pp. 157–168. [DGKT12] S. Datta, A. Gopalan, R. Kulkarni, R. Tewari. “Improved bounds for Bipartite Matching on surfaces”. In: Prooceedings of 29th Symposium on Theoretical Aspects of Computer Science (STACS). 2012. [DKLR09] J. Degorre, M. Kaplan, S. Laplante, J. Roland. “The communication complexity of non- signaling distributions”. In: Proceedings of 34th International Symposium on Mathemati- cal Foundations of Computer Science (MFCS). 2009, pp. 270–281. [EFKR09a] Y. Emek, P. Fraigniaud, A. Korman, A. Rosen.´ “On the Additive Constant of the k-server Work Function Algorithm”. In: Proceedings of 7th Workshop on Approximation and On- line Algorithms. 2009, pp. 128–134. [EFKR09b] Y. Emek, P. Fraigniaud, A. Korman, A. Rosen.´ “Online Computation with Advice”. In: Proceedings of 36th International Colloquium on Automata, Languages and Programming (ICALP). 2009, pp. 427–438. [EHR12] Y. Emek, M. Halldorsson,´ A. Rosen.´ “Space-Constrained Interval Selection”. In: Proceed- ings of the 39th International Colloquium on Automata, Languages and Programming (ICALP). To appear. 2012. [GK11] S. Gharibian, J. Kempe. “Approximation Algorithms for QMA-Complete Problems”. In: Proceedings of 26th IEEE Conference on Computational Complexity (CCC). 2011, pp. 178–188. [GKKRW07a] D. Gavinsky, J. Kempe, I. Kerenidis, R. Raz, R. de Wolf. “Exponential separations for one-way quantum communication complexity, with applications to cryptography”. In: Proceedings of 39th ACM Symposium on Theory of Computing (STOC). 2007, pp. 516– 525. [GWXY10] S. Gordon, H. Wee, D. Xiao, A. Yerukhimovich. “On the round complexity of zero- knowledge proofs from one-way permutations”. In: Proceedings of 1st International Con- ference on Cryptology and Information Security in Latin America. 2010.

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[HMX10] I. Haitner, M. Mahmoody, D. Xiao. “A new sampling protocol and applications to basing cryptographic primitives on NP”. In: Proceeedings of 25th IEEE Conference on Computa- tional Complexity (CCC). 2010, pp. 76–87. [HR07] C. Hess, M. de Rougemont. “A Model of Uncertainty for Near-Duplicates in Document Reference Networks”. In: Proceedings of 11th European Conference on Digital Libraries. 2007, pp. 449–453. [HRS08]S.H emon,´ M. de Rougemont, M. Santha. “Approximate Nash Equilibria for Multi-player Games”. In: Proceedings of 1st International Symposium on Algorithmic Game Theory. 2008, pp. 267–278. [HS07a] C. Hess, K. Stein. “Efficient Calculation of Personalized Document Rankings”. In: Pro- ceedings of 20th International Joint Conference on Artificial Intelligence (IJCAI). 2007, pp. 2778–2783. [HS07b] C. Hess, K. Stein. “Personalized Document Rankings by Incorporating Trust Information From Social Network Data into Link-Based Measures”. In: Proceedings of IJCAI 2007 Workshop on Text-Mining & Link-Analysis. 2007. [ISS07] G. Ivanyos, L. Sanselme, M. Santha. “An efficient quantum algorithm for the hidden subgroup problem in extraspecial groups”. In: Proceedings of 24th Symposium on Theoretical Aspects of Computer Science (STACS). 2007, pp. 586–597. [ISS08a] G. Ivanyos, L. Sanselme, M. Santha. “An efficient quantum algorithm for the hidden subgroup problem in nil-2 groups”. In: Proceedings of 8th Latin American Symposium on Theoretical Informatics (LATIN). 2008, pp. 759–771. [JKKSSZ10a] R. Jain, I. Kerenidis, G. Kuperberg, M. Santha, O. Sattath, S. Zhang. “On the Power of a Unique Quantum Witness”. In: Proceedings 1st Symposium on Innovation in Computer Science (ICS). 2010, pp. 470–481. [JKM12] S. Jeffery, R. Kothari, F. Magniez. “Improving Quantum Query Complexity of Boolean Matrix Multiplication Using Graph Collision”. In: Proceedings of 39th International Col- loquium on Automata, Languages and Programming (ICALP). To appear. 2012. [Ker07b] I. Kerenidis. “Quantum multiparty communication complexity and circuit lower bounds”. In: Proceedings of 4th Conference on Theory and Applications of Models of Computation (TAMC). 2007, pp. 306–317. [KK10] R. Kasher, J. Kempe. “Two-source Extractors Secure Against Quantum Adversaries”. In: Proceedings of 14th International Workshop on Randomization and Computation. 2010, pp. 656–669. [KKLR09] M. Kaplan, I. Kerenidis, S. Laplante, J. Roland. “Non-Local Box Complexity and Secure Function Evaluation”. In: Proceedings of 29th Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS). 2009. [KKMTV08] J. Kempe, H. Kobayashi, K. Matsumoto, B. Toner, T. Vidick. “Entangled games are hard to approximate”. In: Proceedings of 49th IEEE Symposium on Foundations of Computer Science (FOCS). 2008, pp. 447–456. [KKMV08] J. Kempe, H. Kobayashi, K. Matsumoto, T. Vidick. “Using Entanglement in Quantum Multi-Prover Interactive Proofs”. In: Proceedings of 23rd IEEE Conference on Computa- tional Complexity (CCC). 2008, pp. 211–222. [KL09] M. Kaplan, S. Laplante. “Kolmogorov complexity and combinatorial methods in communication complexity”. In: Proceedings of 6th Conference on Theory and Applications of Models of Computation (TAMC). 2009, pp. 261–270.

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[KLLRX12] I. Kerenidis, S. Laplante, V. Lerays, J. Roland, D. Xiao. “Lower bounds on information complexity via zero-communication protocols and applications”. In: Proceedings of 53rd Annual Symposium on Foundations of Computer Science (FOCS). 2012. [KM12] C. Konrad, F. Magniez. “Validating XML Documents in the Streaming Model with Ex- ternal Memory”. In: Proceedings of 15th International Conference on Database Theory (ICDT). 2012. [KMM12] C. Konrad, F. Magniez, C. Mathieu. “Maximum Matching in Semi-Streaming with Few Passes”. In: Proceedings of 15th International Workshop on Approximation Algorithms for Combinatorial Optimization Problems (APPROX). To appear. 2012. [KMOR10] H. Krovi, F. Magniez, M. Ozols, J. Roland. “Finding is as easy as detecting for quantum walks”. In: Proceedings of 37st International Colloquium on Automata, Languages and Programming (ICALP). 2010, pp. 540–551. [KR10] J. Kempe, O. Regev. “No Strong Parallel Repetition with Entangled and Non-signaling Provers”. In: Proceeedings of 25th IEEE Conference on Computational Complexity (CCC). 2010, pp. 7–15. [KRT08] J. Kempe, O. Regev, B. Toner. “Unique Games with Entangled Provers are Easy”. In: Proceedings of 49th IEEE Symposium on Foundations of Computer Science (FOCS). 2008, pp. 457–466. [KV11] J. Kempe, T. Vidick. “Parallel repetition of entangled games”. In: Proceedings of 43rd ACM Symposium on Theory of Computing (STOC). 2011, pp. 353–362. [KZ12] I. Kerenidis, S. Zhang. “A quantum protocol for sampling correlated equilibria unconditionally and without a mediator”. In: Proceedings of 7th Theory of Quantum Computation, Communication and Cryptography (TQC). 2012. [LLR12] S. Laplante, V. Lerays, J. Roland. “Classical and quantum partition bound and detector in- efﬁciency”. In: Proceedings of the 39th International Colloquium on Automata, Languages and Programming (ICALP). 2012. [LPSR07] Z. Lotker, B. Patt-Shamir, A. Rosen.´ “Distributed approximate matching”. In: Proceedings of 26th ACM Symposium on Principles of Distributed Computing (PODC). 2007, pp. 167– 174. [MMN10] F. Magniez, C. Mathieu, A. Nayak. “Recognizing well-parenthesized expressions in the streaming model”. In: Proceedings of 42nd ACM Symposium on Theory of Computing (STOC). 2010, pp. 261–270. [MNRS07] F. Magniez, A. Nayak, J. Roland, M. Santha. “Search via quantum walk”. In: Proceedings of 39th ACM Symposium on Theory of Computing (STOC). 2007, pp. 575–584. [MNRS09] F. Magniez, A. Nayak, P. Richter, M. Santha. “On the hitting times of quantum versus random walks”. In: Proceedings of 20th ACM-SIAM Symposium on Discrete Algorithms (SODA). 2009, pp. 86–95. [MNSX11] F. Magniez, A. Nayak, M. Santha, D. Xiao. “Improved bounds for the randomized decision tree complexity of recursive majority”. In: Proceedings of 38th International Collo- quium on Automata, Languages and Programming (ICALP). 2011, pp. 317–329. [MRSZ11] F. Magniez, M. de Rougemont, M. Santha, X. Zeitoun. “The complexity of approximate Nash equilibrium in congestion games with negative delays”. In: Proceedings of 7th Work- shop on Internet and Network Economics (WINE). 2011, pp. 266–277.

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[MX10] M. Mahmoody, D. Xiao. “On the power of randomized reductions and the checkability of SAT”. In: Proceeedings of 25th IEEE Conference on Computational Complexity (CCC). 2010, pp. 64–75. [PCWDK12b] A. Pappa, A. Chailloux, S. Wehner, E. Diamanti, I. Kerenidis. “Multiparty entanglement veriﬁcation resistant against dishonest parties”. In: Proceedings of 7th Theory of Quantum Computation, Communication and Cryptography (TQC). 2012. [Ric08b] P. Richter. “The quantum complexity of Markov chain Monte Carlo”. In: Proceedings of 3rd Conference on Computability in Europe (CiE). 2008, pp. 511–522. [Rou09] M. de Rougemont. “The value of sponsored ads for XML documents”. In: Proceedings of 9th International Conference on Electronic Business. 2009. [RR09]H.R acke,¨ A. Rosen.´ “Approximation algorithms for time-constrained scheduling on line networks”. In: Proceedings of 21st ACM Symposium on Parallelism in Algorithms and Architectures (SPAA). 2009, pp. 337–346. [RR11b] M. Renault, A. Rosen.´ “On online algorithms with advice for the k-server problem”. In: Proceedings of 9th Workshop on Approximation and Online Algorithms. (Invited to the Special issue of WAOA2011). 2011. [RS07] A. Rosen,´ G. Scalosub. “Rate vs. buffer size: greedy information gathering on the line”. In: Proceedings of 19th ACM Symposium on Parallelism in Algorithms and Architectures (SPAA). 2007, pp. 305–314. [RT09] M. de Rougemont, M. Tracol. “Statistical Analysis for Probabilistic Processes”. In: Pro- ceedings of 24th IEEE Symposium on Logic in Computer Science (LICS). 2009, pp. 299– 308. [RV07] M. de Rougemont, A. Vieilleribiere.` “Approximate Data Exchange”. In: Proceedings of 11th International Conference on Database Theory (ICDT). 2007, pp. 44–58. [RV10] M. de Rougemont, A. Vieilleribiere.` “Approximate Structural Consistency”. In: Proceed- ings of 36th International Conference on Current Trends in Theory and Practice of Com- puter Science. 2010, pp. 685–696. [Xia10] D. Xiao. “Learning to create is as hard as learning to appreciate”. In: Proceedings of 23rd International Conference on Learning Theory (COLT). 2010, pp. 516–518. [Xia11b] D. Xiao. “(Nearly) Round-Optimal Black-Box Constructions of Commitments Secure against Selective Opening Attacks”. In: Proceedings of 8th Theory of Cryptography Con- ference (TCC). 2011, pp. 541–558. [Xia12] D. Xiao. “Round-optimal black-box statistically binding selective-opening secure commitments”. In: Proceedings of 5th International Conference on Cryptology in Africa (AFRICACRYPT). To appear. 2012.

C-COM : International or national conferences without proceedings

[BHKKLS11b] G. Brassard, P. Høyer, K. Kalach, M. Kaplan, S. Laplante, L. Salvail. “Merkle Puzzles in a Quantum World”. In: First Annual Conference on Quantum Cryptography. 2011. [BHKKLS12] G. Brassard, P. Høyer, K. Kalach, M. Kaplan, S. Laplante, L. Salvail. “Merkle Puzzles in a Quantum World”. In: 15th Workshop on Quantum Information Processing. Featured talk. 2012. [CK10] A. Chailloux, I. Kerenidis. “Optimal Quantum Strong Coin Flipping”. In: 13th Workshop on Quantum Information Processing. Plenary talk. 2010.

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[CK11b] A. Chailloux, I. Kerenidis. “Optimal bounds for quantum bit commitment”. In: 14th Work- shop on Quantum Information Processing. Featured talk. 2011. [DISW11b] T. Decker, G. Ivanyos, M. Santha, P. Wocjan. “Hidden Symmetry Subgroup Problems”. In: 15th Workshop on Quantum Information Processing. Contributed talk. 2011. [DKRL08] J. Degorre, M. Kaplan, J. Roland, S. Laplante. “The complexity of simulating non- signaling distributions”. In: 11th Workshop on Quantum Information Processing. Con- tributed talk. 2008. [GK12] S. Gharibian, J. Kempe. “Hardness of approximation for quantum problems”. In: 15th Workshop on Quantum Information Processing. Contributed talk. 2012. [GKKRW07b] D. Gavinsky, J. Kempe, I. Kerenidis, R. Raz, R. de Wolf. “Exponential separations for one-way quantum communication complexity, with applications to cryptography”. In: 10th Workshop on Quantum Information Processing. Featured talk. 2007. [ISS08b] G. Ivanyos, L. Sanselme, M. Santha. “An efﬁcient quantum algorithm for the hidden subgroup problem in nil-2 groups”. In: 12th Workshop on Quantum Information Processing. Featured talk. 2008. [JKKSSZ10b] R. Jain, I. Kerenidis, G. Kuperberg, M. Santha, O. Sattath, S. Zhang. “On the Power of a Unique Quantum Witness”. In: 13th Workshop on Quantum Information Processing. Contributed talk. 2010. [KMOR11] H. Krovi, F. Magniez, M. Ozols, J. Roland. “Finding is as easy as detecting for quantum walks”. In: 14th Workshop on Quantum Information Processing. Featured talk. 2011.

Participation under invitation to scientiﬁc meetings

Singapore Workshop on Quantum Algorithms and Complexity Theory, Singapore, November 2008. I. Kerenidis, S. Laplante, F. Magniez, M. Santha (organizer). Dagstuhl 2nd DYNAMO Workshop: Dynamic Communication Networks, Dagstuhl seminar, June 2009. A. Rosen.´ Santa Barbara Quantum Information Science, Kavli Institue for Theoretical Physics, Santa Barbara, Septembre 2009. F. Magniez. Tokyo International Conference on Quantum Information and Technology, National Institute of Infor- matics, Tokyo, December 2009. A. Chailloux, I. Kerenidis, M. Santha. Dagstuhl Scheduling, Dagstuhl seminar, February 2010. A. Rosen.´ Dagstuhl Packing and Scheduling Algorithms for Information and Communication Services, Dagstuhl seminar, February 2011. A. Rosen.´ DIMACS DIMACS Workshop on Competitive Algorithms for Packet Scheduling, Buffering and Routing in the Internet, DIMACS workshop, July 2011. A. Rosen´ (co-organizer). Dagstuhl Quantum Cryptanalysis, Dagstuhl seminar, September 2011. F. Magniez, L. Magnin. Montreal Workshop on Quantum Computer Science, Universite´ de Montreal,´ 2011. S. Laplante. Bristol 2nd Heilbronn Quantum Algorithms Day, University of Bristol, February 2012. M. Santha. Waterloo Recent Progress in Quantum Algorithms, Institute for Quantum Computing, Waterloo, Canada (Ontario), April 2012. F. Magniez. Dortmund Streaming Algorithms and Related Topics, TU Dortmund University, Germany, July 2012. C. Konrad, F. Magniez. Aarhus Workshop on Synergies in Lower Bounds, Aarhus University, Denmark. June 28 – July 1, 2011. D. Xiao.

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Tsingua Trends in Theoretical Cryptography, IIIS Tsinghua University, China. January 7-9, 2011. D. Xiao.

DO : Editing of journals and other works

[MN09] F. Magniez, A. Nayak, eds. Special issue in Quantum Computation, Algorithmica 55(3). Springer, 2009.

OS : Scientiﬁc works

[KV10] J. Kempe, T. Vidick. “Quantum Information, Computation and Cryptography”. In: ed. by F. Benatti, M. Fannes, R. Floreanini, and D. Petritis. Vol. 808. Springer Lecture Notes in Physics. Springer, 2010. Chap. Quantum Algorithms, pp. 309–342.

PV : Popularization works

[Lap10] S. Laplante. “Le plus grand des hasards : Surprises quantiques”. In: ed. by J.-F. Dars and A. Papillaut. Belin, 2010. Chap. L’inﬂuence de l’informatique, pp. 152–154.

AP : Other works

[DISW11a] T. Decker, G. Ivanyos, M. Santha, P. Wocjan. Hidden Symmetry Subgroup Problems. Tech. rep. 1107.2189. arXiv, 2011. [IKLSW12] G. Ivanyos, H. Klaux, T. Lee, M. Santha, R. de Wolf. New bounds on the classical and quantum communication complexity of some graph properties. Tech. rep. 1204.4596. arXiv, 2012. [Kul10] R. Kulkarni. Perfect matching in bipartite planar graphs is in UL. Tech. rep. 201. ECCC, 2010. [LMS11] T. Lee, F. Magniez, M. Santha. A learning graph based quantum query algorithm for finding constant-size subgraphs. Tech. rep. 1109.5135. arXiv, 2011. [MX12] Mohammad Mahmoody, David Xiao. Languages with efficient Zero Knowledge PCPs are in SZK. Tech. rep. TR12-052. ECCC, 2012. [Ric07c] P. Richter. Two remarks on the local Hamiltonian problem. Tech. rep. arXiv:0712.4274. ArXiv, 2007. [Ric08a] P. Richter. “Quantum algorithms for triangle finding”. In: Encyclopedia of Algorithms. Springer, 2008. [RS08] P. Richter, M. Szegedy. “Quantization of Markov chains”. In: Encyclopedia of Algorithms. Springer, 2008. [Xia11a] D. Xiao. Is privacy compatible with truthfulness? Tech. rep. 2011/005. Cryptology ePrint Archive, 2011.

66 Chapter 6

Appendix: Algorithms and Complexity

6.1 Composition and team organization

Leader : Miklos Santha

6.1.1 Current members

6.1.1.1 Permanent members (2012)

1. Iordanis Kerenidis, CR1 CNRS, HDR 2. Fred´ eric´ Magniez, DR2 CNRS 3. Adi Rosen,´ DR2 CNRS 4. Michel de Rougemont, Pr1 (Universite´ Pantheon-Assas)´ 5. Miklos Santha, DR1 CNRS 6. David Xiao, CR2 CNRS 6.1.1.2 Ph.D students and post-doctoral researchers (2012)

PhD Students. 1. Nathanael¨ Franc¸ois 2. Christian Konrad 3. Virgine Lerays 4. Anna Pappa 5. Marc Renault 6. Xavier Zeitoun

Postdocs. 1. Raghav Kulkarni (2 years)

6.1.1.3 Others (2012)

1. Sophie Laplante, PR2 (LRI, Universite´ Paris-Sud), associate member 2. Julia Kempe, DR2, currently on leave We also list the students that are currently doing an internship in our group as Master students (2nd year) in France. 1. Krzysztof Gogolewski, MPRI 2. Mathieu Lauriere,` MPRI

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6.1.2 Former members

6.1.2.1 Permanent members (2007-2011)

1. Nisheeth Vishnoi 2008-09, CR1 CNRS, now at Microsoft Research India, Bangalore 2. Julia Kempe, 2007, CR1 CNRS, and 2010-11, DR2 CNRS, on leave.

6.1.2.2 Ph.D students and post-doctoral researchers (2007-2011)

PhD Students. 1. Julien Degorre, 2003-2007, now postdoc at Centre for Quantum Technologies, National Univer- sity of Singapore 2. Luc Sanselme, 2004-2008, now Professor of Mathematics in Nancy at “classes preparatoires”´ 3. Marc Kaplan, 2005-2009, now postdoc at Tel´ ecom´ ParisTech, Paris 4. Claudia Hess, 2003-2007, now Researcher at Systec-CAx, Germany 5. Adrien Vieilleribiere,` 2003-2008, now postdoc at Ligaran (startup on Ebooks), Paris 6. Mathieu Tracol, 2006-2009, now postdoc at Institute of Science and Technology, Vienne, Autriche 7. Andre´ Chailloux, 2007-11, now postdoc at University of California, Berkeley 8. Lo¨ıck Magnin, 2007-11, now postdoc at Centre for Quantum Technologies, National University of Singapore

Postdocs. 1. Troy Lee, 2006–07, now at CQT, Singapore 2. Peter Richter, 2007-08, now at Goldman Sachs 3. David Xiao, 2009-2011, now CR2 in the team

6.1.2.3 Long-term visitors (2007-2011)

1. Takeshi Koshiba, April 2010 - March 2011, Saitama University, Japan 2. Michael McGettrick, May 2009 - October 2009, National University of Ireland, Galway (UK)

6.1.2.4 Others (2007-2011)

First we list the students that made an internship in our group while they were Master students (2nd year) in France. 1. Andre´ Chailloux, MPRI, 2007 2. Lo¨ıck Magnin, ENS Lyon, 2007 3. Mauricio Soto, MPRI, 2007 4. Anna Pappa, MPRI, 2007 5. Thomas Largilliers, MPRI, 2007 6. Omar Fawzi, MPRI, 2008 7. Marc Renault, MPRI, 2010. 8. Nathanael¨ Franc¸ois, MPRI, 2011 9. Virginie Lerays, M2 Logique Paris 7, 2011 10. Karolina Soltys, MPRI, 2011

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11. Suppartha Podder, MPRI, 2011 12. Vincent Vong, MPRI, 2011 In addition we hosted several students from University of Waterloo, Canada (Ontario), for 4-month visits. Indeed, we were leader of a student exchange program between Europe and Canada (CSQIP) between 2008 and 2011. This grant supported Master and PhD students exchanges. Below is the list of students with their respective starting period of visit: 1. Jamie Sikora (January 2010) 2. Stacey Jeffery (January 2010 and September 2011) 3. Sevag Gharibian (July 2010) 4. Ansis Rosmanis (September 2010) 5. Sarvagya Upadhyay (January 2011) We also hosted IIT (Kanpur) students from India for 3-month visits. 1. B. Bhuvneshwar (2010) 2. S. Kumar (2010)

6.1.3 Visitors

1. Ashish Goel, Stanford, USA 2.G abor´ Ivanyos, SZTAKI, Budapest, Hungary 3. Zvi Lotker, Ben-Gurion University, Israel 4. Claire Mathieu, Brown University, Providence, USA (Rhode Island) 5. Dieter van Melkebeek, University of Wisconsin, Madison, USA 6. Ashwin Nayak, Institute for Quantum Computing, University of Waterloo, Canada (Ontario) 7. Boaz Patt-Shamir, Tel-Aviv University, Israel 8. Oded Regev, Tel Aviv University, Israel 9. Pranab Sen, Tata Institute for Fundamental Research, Mumbai, India 10. Umesh Vazirani, University of California, Berkeley, USA 11. Ronald de Wolf, CWI, Amsterdam, The Netherlands

6.1.4 Team organization

6.1.4.1 Funding and resource management

See Section 1.4

6.1.4.2 Team Seminar

Available at LRI http://www.liafa.univ-paris-diderot.fr/algocomp/index.php?n= Main.LRI-Seminar LIAFA http://www.liafa.univ-paris-diderot.fr/web9/manifsem/ listmanifannee_fr.php?typecongres=10

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6.1.4.3 Participation in the scientiﬁc community and administrative responabilities

Participation in international scientiﬁc activities. LIA Japanese - French Laboratory for Informatics (JFLI) 2009-2011, M. Santha (scientiﬁc leader for “Quantum Computing”) UMI Participating team in Japanese - French Laboratory for Informatics (JFLI) since 2011, I. Kerenidis (coordinator for LIAFA) LIA Participating team in France-Singapore Quantum Physics and Information Lab (FSQL) since 2010, M. Santha (coordinator for LIAFA) LEA Co-director of the French-Israeli Laboratory on Foundations of Computer Science (FILOFOCS), a CNRS LEA between LIAFA and Tel-Aviv University (2012-2015, extendable for another 4 years). Adi Rosen.´

Participation in national and local scientiﬁc activities. DIGITEO Labs Member of the Programme Committee, 2007 (M. Santha). GDR Research group (GDR) Informatique Mathematique´ . First, we are involved in its steering com- mitee within the axis Logique et Compexite´ (F. Magniez, since 2009). Second, we lead two of its research groups (GT): GT Complexite´ et Modeles` Finis (M. de Rougemont until 2010) and GT Informatique Quantique (2006-09: F. Magniez, 2009-: I. Kerenidis and S. Laplante). GDR GDR Information et Communication Quantique (J. Kempe until 2007, then I. Kerenidis until 2009), and then GDR Information Quantique, Fondements & Applications (I. Kerenidis since 2010) UFR Conseil Scientiﬁque UFR Informatique Paris Diderot 7 (since 2011). I. Kerenidis ED Member of the conseil de l’ecole´ doctorale, Universite´ Paris-Sud 11. M. de Rougemont (until 2010), S. Laplante (2011-)

6.2 Grants and research projects

6.2.1 Management of international projects

MarieCurie (2006-2008) FP6 Marie Curie International Reintegration Grant MIRG-CT-2005-036557 Quantum Information and Applications to communication, cryptography and classical computer science (QCCC), I. Kerenidis, 80 KEUR. QACT (2007-08) Quantum algorithms and complexity theory, France-Canada Research Foundation, coordinator F. Magniez. Canadian partner: University of Waterloo (Ontario). Amount: 14 KEUR. HSP (2008-09) Hidden subgroup problem, CNRS - Hungarian Academy joint project with the Renyi´ Institute, coordinator M. Santha. Amount: 7 KEUR. QCTFS (2008-10) Quantum Computation: Theory and Feasibility, Strategic France (CNRS) - Japan (JST) Cooperative Program. French Partners: Univ Paris-Sud (coordinator I. Kerenidis), Univ Grenoble, Telecom ParisTech. Japanese Partners: NII Tokyo, Univ Tokyo, Kyoto Univ, Saitama Univ. Amount: 90 KEUR. CSQIP (2008-11) Collaborative student training in Quantum Information Processing, Transatlantic Exchange Partnerships, EU-Canada programme. EU partners: Ecole Polytechnique, Universite´ Paris-Sud (coordinator F. Magniez), University of Erlangen (Germany), University of Innsbruck (Austria). Canadian partners: University of Waterloo (Ontario), University of Calgary (Alberta). Amount for Europe: 138 KEUR.

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STIC-Asie (2010-2012) MAEE-CNRS STIC-Asie Programme Foundations of Quantum Information and Computation, French Partner: LIAFA (coordinator I. Kerenidis). Asia partners: Centre for Quantum Technologies (Singapore), Tata Institute for Fundamental Research (India), Chinese University of Hong Kong (Hong Kong). Amount: 42 KEUR. 6.2.2 Management of national projects

ALGOQP (2005-08) Quantum and Probabilistic Algorithms, ANR Blanc, coordinator S. Laplante. Amount: 280 KEUR. VERAP (2008-11) Approximate Veriﬁcation of Probabilistic Systems, ANR Sesur, 117 KEUR, coordinator M. de Rougemont. Partner: Equipe de Logique Mathematique´ (Universite´ Paris Diderot). Amount: 160 KEUR. QRAC (2009-12) Quantum and Randomized Algorithms and Complexity, ANR program DEFIS, coordinator F. Magniez, 420 KEUR. CRYQ (2010-13) Cryptographie quantique, ANR JCJC, coordinator I. Kerenidis, 195 KEUR. NeTOC (2012-15) New Techniques in Online Computation, ANR Blanc, coordinator A. Rosen, Partner: LIP6. Amount: 132 KEUR. RDAM (2013-16) Algorithmic Techniques for Restricted Data Access Models, ANR Blanc (accepted in july 2012), coordinator F. Magniez. Partners: “Distributed Algorithms and Graphs” team of LIAFA and ENS LIENS. Amount: 355 KEUR (subject to further adjustments). 6.2.3 Participation in international projects

QAP (2005-10) Qubit Applications, EU 6th Framework Integrated Project IST-2003-015848 with 35 scientiﬁc and industrial partners: http://www.qubitapplications.com/Partners/ list.asp. Coordinator M. Santha, amount: 165 KEUR. Principal investigator: Ian Walmsley, University of Oxford. QCS (2011-13) Quantum Computer Science, FET ICT Open Call Strep FP7-ICT-2009-255961, coordinator M. Santha, 264 KEUR, http://www.lu.lv/qcs/. EU partners: University of Latvia, CNRS LIAFA, University of Bristol, CWI (Netherlands), Tel Aviv University, Universite´ Libre de Bruxelles, Institute of Photonic Sciences (Spain), University of Cambridge (United Kingdom). Principal Investigator: Andris Ambainis, University of Latvia. DIQIP (2012-14) Device-Independent Quantum Information Processing, ANR CHIST-ERA, coordinator S. Laplante, 207 KEUR. EU partners: Institute of Photonic Sciences (Spain), GAP-Optique and ETH (Switzerland), Universite´ Paris-Sud, Universite´ Libre de Bruxelles, University of Bristol, University of London Royal Holloway. Principal Investigator: Antonio Acin, Institute of Photonic Sciences, Barcelona, Spain. 6.2.4 Participation in local projects

PPF Programme Publi-Formations “Information Quantique” at Universite´ Paris-Sud (2006-09). F. Magniez (responsible for the team). 6.2.5 Participation in local projects 6.3 Research administration

6.3.1 Editorial duties

6.3.1.1 Editorial board member

IJQI International Journal of Quantum Information, M. Santha since 2008

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ToCT ACM Transactions on Computation Theory, S. Laplante since 2007. Algorithmica Special issue on Quantum Computation in Algorithmica, F. Magniez (guest editor), 2009

6.3.2 Management of scientiﬁc conferences

6.3.2.1 Steering committee member

FCT Fundamentals of Computation Theory M. Santha since 1999 QIP Quantum Information Processing M. Santha 2002-07. STACS Symposium on Theoretical Aspects of Computer Science. M. Santha 2002-08, Adi Rosen´ 2009- present.

6.3.2.2 Program committee member

AQIS 7th Asian Conference on Quantum Information Science, Kyoto, 2007, J. Kempe and M. Santha STACS 24th Symposium on Theoretical Aspects of Computer Science, Aachen, Germany, 2007, S. Laplante WAOA 5th Workshop on Approximation and Online Algorithms, Eilat, Israel, 2007, Adi Rosen´ CiE 3rd Computability in Europe, Siena, 2007, J. Kempe. 2008, S. Laplante. STACS 25th Symposium on Theoretical Aspects of Computer Science, Bordeaux, 2008, F. Magniez CiE 4th Computability in Europe, Athens, 2008, S. Laplante SCN 8th Conference on Security and Cryptography for Networks, Boston, USA, 2008, Adi Rosen´ APPROX 15th International Workshop on Approximation Algorithms for Combinatorial Optimization Problems, Amalﬁ, Italy, 2008, Adi Rosen´ PODC 27th AnnualSymposium on Principles of Distributed Computing, Toronto, Canada, 2008 Adi Rosn´ TAMC 6th Annual Conference on Theory and Applications of Models of Computation, Xian, 2009, M. Santha STACS 26th International Symposium on Theoretical Aspects of Computer Science, Freiburg, Ger- many, 2009, Adi Rosen´ TQC 5th Conference on Theory of Quantum Computation, Communication and Cryptography, Leeds, 2010, M. Santha AQIS 10th Asian Conference on Quantum Information Science, Tokyo, 2010, J. Kempe and M. Santha QIP Quantum Infomration Processing, Zurich, 2010, J. Kempe and I. Kerenidis IPDPS 24th International Parallel & Distributed Processing Symposium, Atlanta, USA, 2010, Adi Rosen´ SEA 9th International Symposium on Experimental Algorithms, Ischia Islans (Napoli), Italy, 2010, Adi Rosen´ QIP Quantum Infomration Processing, Singapore, 2011, I. Kerenidis TQC 6th Conference on Theory of Quantum Computation, Communication and Cryptography, Madrid 2011, M. Santha CSR 5th International Computer Science Symposium in Russia, St. Petersburg, 2011, M. Santha STOC 43rd ACM Symposium on Theory of Computing, San Jose, USA (California), 2011, F. Magniez SOFSEM 38th International Conference on Current Trends in Theory and Practice of Computer Sci- ence, Czech Republic, 2012, F. Magniez

72 CHAPTER 6. APPENDIX: ALGORITHMS AND COMPLEXITY

STACS 29th Symposium on Theoretical Aspects of Computer Science, Paris, 2012, M. de Rougemont CCC 27th Conference on Computational Complexity, Porto, Portugal, 2012, J. Kempe STACS 30th Symposium on Theoretical Aspects of Computer Science, Kiel, 2013, I. Kerenidis

6.3.3 Organization of scientiﬁc events

6.3.3.1 Local arrangements committee chair

CCC 24th IEEE Conference on Computational Complexity, Paris, 2009. S. Laplante, chair.

6.3.3.2 Local arrangements committee member

We mostly organized French scientiﬁc events, mainly hosted by the GDR Informatique Mathematique,´ or by the Telecom-ParisTech and LIAFA collaboration. GDR-IM Journees´ annuelles du GDR Informatique Mathematique,´ Paris, 2012 (F. Magniez) GDR-IM/GT-IQ Journees´ du GT Informatique Quantique, Paris, January 2008 (F. Magniez), Septem- ber 2008 (F. Magniez), September 2010 (I. Kerenidis), May 2011 (I. Kerenidis), May 2012 Journees´ communes avec la Fed´ eration´ de Recherche en Mathematiques´ de Paris centre (I. Kereni- dis) QUPA Quantum Information in Paris workshops, Paris, May 2009, October 2009, February 2010, May 2010, September 2010, February 2011, May 2011, September 2011, April 2012 (I. Kerenidis) We did also participate to the organization of international events. QACT Workshop on Quantum Algorithms and Complexity Theory, Singapore, November 2008, M. Santha CCC 24th IEEE Conference on Computational Complexity, Paris, 2009, full group Qmath Quantum Information, Hradec Kralove, Czech Republic, 2010, J. Kempe DIMACS DIMACS Workshop on Competitive Algorithms for Packet Scheduling, Buffering and Routing in the Internet, DIMACS center, Rutgers University, July 2011. A. Rosen.´ FILOFOCS French - Israeli Workshop on Foundations of Computer Science, Paris, May 2012. A. Rosen.´

6.3.4 Participation in scientiﬁc juries and committees

6.3.4.1 International

ICT-FET Expert 2007-2012, M. Santha NSERC Natural Sciences and Engineering Research Council of Canada Evaluation Group, Computer Science, 2010–2013, S. Laplante.

6.3.4.2 National

ANR Comite´ d’evaluation´ DEFIS 2008.

6.3.4.3 Commissions of specialists

Orsay Chaire INRIA/Universite´ Paris-Sud, 2010, F. Magniez (head of the committee) INRIA Concours CR2-CR1 INRIA Saclay, 2009, F. Magniez Orsay Universite´ Paris-Sud, 2007-09, F. Magniez, A. Rosen´ Lille Universite´ Lille, 2011, M. de Rougemont Nancy Universite´ Nancy, 2012, M. de Rougemont

73 CHAPTER 6. APPENDIX: ALGORITHMS AND COMPLEXITY

6.4 Teaching, advising, and evaluation activities

6.4.1 Theses and HdR defended

6.4.1.1 Habilitations a` diriger les recherches

1. Fred´ eric´ Magniez, Veriﬁcation´ approchee´ – Calcul quantique, May 2007 2. Julia Kempe, Quantum Computation, September 2010 3. Iordanis Kerenidis, Interaction in the quantum world, December 2010

6.4.1.2 Doctoral theses

1. Julien Degorre, Quantifier la non-localite´, September 2007, Universite´ Paris-Sud. Advisors: S. Laplante et M. Santha. Now postdoc at Centre for Quantum Technologies, National University of Singapore. 2. Luc Sanselme, Algorithmes quantiques dans les groupes nilpotents, December 2008, Universite´ Paris-Sud. Advisor: M. Santha. Now professor of Mathematics in “classes preparatoires”.´ 3. Marc Kaplan, Methodes´ combinatoires et algebriques en complexite´ de la communication, Septembre 2009, Universite´ Paris-Sud. Advisor: S. Laplante. Now postdoc at Tel´ ecom´ Paris- Tech. 4. Claudia Hess, Trust-based Digital Libraries, 2007, Universite´ Paris-Sud and Bayreuth, Co- Advisor: M. de Rougemont. Now Researcher at Systec-CAx in Munich.¨ 5. Adrien Vieilleribiere,` Transformations de mots, d’arbres et de statistiques , 2008, Universite´ Paris- Sud, Advisor: M. de Rougemont. Now postdoc at Ligaran, Paris. 6. Mathieu Tracol, Verification´ approchee´ de systemes` probabilistes, 2009, Universite´ Paris-Sud. Advisor: M. de Rougemont. Now postdoc at Institute of Science and Technology, Vienna, Austria. 7. Andre´ Chailloux, Quantum coin flipping and bit commitment: optimal bounds, pratical constructions and computational security, June 24, 2011, Universite´ Paris-Sud. Advisor: I. Kerenidis Now postdoc at University of California, Berkeley. 8. Lo¨ıck Magnin, Two-player interaction in quantum computing: cryptographic primitives and query complexity, December 5, 2011, Universite´ Paris-Sud. Advisors (co-tutelle): Nicolas Cerf (Uni- versite´ Libre de Bruxelles) and F. Magniez. Now postdoc at Centre for Quantum Technologies, National University of Singapore.

6.4.2 Thesis reports

1. Aurelien Bocquet, ’Modeles` de securit´ e´ realistes´ pour la distribution quantique de cles’,´ Telecom ParisTech, 2011. 2. Yann Strozecki, Complexite´ d’enum´ eration´ et decomposition´ de matro¨ıdes, Universite´ Paris VII, Decembre´ 2010

6.4.3 Teaching

6.4.3.1 University courses at M2R level

MPRI Advanced Algorithms, in the Paris Computer Science Master’s Programme (MPRI), every year, F. Magniez, M. de Rougemont, A. Rosen,´ M. Santha MPRI Quantum information and applications, in the Paris Computer Science Master’s Programme (MPRI), every year, I. Kerenidis, S. Laplante, F. Magniez, M. Santha

74 CHAPTER 6. APPENDIX: ALGORITHMS AND COMPLEXITY

MPRI Randomness in Complexity, in the Paris Computer Science Master’s Programme (MPRI), since 2011, I. Kerenidis, S. Laplante, M. Santha, D. Xiao ENS-Lyon New computation paradigms: physics-like models of computation, efﬁcient algorithmics, int the ENS-Lyon Computer Science Master’s Programme (MIF), 2010, F. Magniez LMFI Approximate Veriﬁcation and Complexity, Master Paris-Diderot, Logique Mathematique´ et Fondements de l’Informatique, since 2011, M. de Rougemont

6.4.3.2 Special thematic programs and specialist courses

EJCJC “Ecole des Jeunes Chercheurs en Informatique Mathematique”,´ Clermont-Ferrand, 2009. Or- ganization and course in quantum computing. F. Magniez SMS-NATO Advanced School in “Quantum Information Processing and Quantum Cryptography”, Montreal, Canada, 2010. J. Kempe and M. Santha. ALEA Journees´ ALEA, ecole´ thematique´ du CNRS. “Le pseudo-alea:´ objets et gen´ eration.”´ CIRM, Universite´ Aix-Marseille I, 2012. D. Xiao. EPIT “Ecole de Printemps d’Informatique Theorique”,´ 2012. Organization and courses in randomized algorithms, approximation algorithms, streaming algorithms, communication complexity, and quantum computing. I. Kerenidis and F. Magniez (chair).

6.4.3.3 Popularization

College` Belgique Lecture in quantum computing, 2009. F. Magniez ENS Lyon Invited lecture, Alan Turing’s Heritage, 2012. S. Laplante Fondation Sciences Mathematiques´ de Paris. Invited talk: Les preuves, revisitees´ . Mathematics in motion, 2012. D. Xiao. Projects & expositions J. Kempe, I. Kerenidis and S. Laplante were consulted to several projects and expositions developed by Sylvie Tissot, from Anabole (Paris, small multimedia company): Quantum design: Project for visual representation of quantum states and quantum circuits http://www.anabole.com/quantum-design/ Harmonices quanti: Project for auditive representation of quantum states, http://harmonices-quanti.com Feteˆ de la Science: Presentation of a software for quantum computing at LRI, 2009 and 2010 Gaˆıte´ Lyrique: Exhibition 2062 of the quantum-design software, 2012.

6.4.3.4 Technology transfer

Ligaran Cooperation and expertise with Ligaran (Paris, startup on Ebooks) on tree transducers (XSLT), approximate validity and correctors. M. de Rougemont. IDQuantique Collaboration with the company IDQuantique (Geneva, company on quantum technologies for communication and security) on extending the functionalities of their commercial Clavis2 Quantum Key Distribution product to include the Coin Flipping and Bit Commitment primitives. Experiment is under way at the quantum optics laboratory at Telecom ParisTech. I. Kerenidis.

75 CHAPTER 6. APPENDIX: ALGORITHMS AND COMPLEXITY

76 Partie III

Equipe Algorithmes Distribues´ et Graphes

Chapitre 1

Rapport scientiﬁque : Algorithmes Distribues´ et Graphes L’equipe´ ”Algorithmes et combinatoire” qui existait au 1er janvier 2007, s’est scindee´ en 2010 en deux equipes.´ Ce rapport ne concerne pour 2007-2010 que les membres de l’equipe´ ”Algorithmes et combinatoire” qui sont maintenant membres de l’equipe´ ”Algorithmique distribuee´ et graphes” et pour 2011-2012 les membres de l’equipe´ ”Algorithmique distribuee´ et graphes”.

1.1 Thematique´ gen´ erale´ et principaux objectifs

1.1.1 Introduction

Les recherches de l’equipe´ couvrent le spectre complet de l’algorithmique des graphes (incluant tous les aspects lies´ a` la theorie´ des graphes) a` l’algorithmique distribuee´ en passant par les applications aux reseaux.´ Ainsi l’equipe´ possede` une forte expertise en algorithmique pour les decompositions´ de graphes, et en conception et analyse d’algorithmes conçus pour des familles specifiques´ de graphes. Elle couvre par ailleurs la plupart des thematiques´ de l’algorithmique distribuee,´ du developpement´ de protocoles distribues´ pour les reseaux´ (routage, etiquetage,´ coloration, spanners, etc.) a` la tolerance´ aux pannes (consensus, election´ de leader, detecteurs´ de defaillances,´ etc.). Une partie des membres de l’equipe´ sont membres de l’equipe´ projet Inria ”Gang” ( Networks, graphs and algorithms) dont l’objectif est le developpement´ de methodes´ algorithmiques pour la conception et le controleˆ des reseaux´ a` grande echelle.´ Au cours de ces 5 annees,´ l’equipe´ ”Algorithmique distribuee´ et graphes” a beaucoup evolu´ e´ et s’est considerablement´ renforcee.´ L’arrivee´ de Pierre Fraigniaud en janvier 2007 par une mutation depuis le LRI, de Carole Delporte et de Hugues Fauconnier en octobre 2007 par un changement d’equipe´ au sein du LIAFA, et enfin le recrutement de Amos Korman (CR CNRS), ont permis de constituer une forte composante ”algorithmique distribuee”,´ cette composante s’est encore renforcee´ par l’arrivee´ en 2008 de Nicolas Schabanel (mutation CNRS Chili) et en 2010 de Fabien Mathieu (CDD Inria). Ainsi les deux sous communautes´ du calcul distribue´ : calcul tolerant´ aux pannes et calcul reseau´ sont particulierement` bien represent´ ees.´ La thematique´ algorithmique des graphes s’est renforcee´ par l’arrivee´ en 2007 de Mathieu Raffinot (mutation CNRS Russie) et les aspects plus lies´ a` la theorie´ des graphes se sont renforces´ en 2008 par les recrutements de Nicolas Trotignon (CR CNRS) et Jean-Sebastien´ Sereni (CR CNRS). L’equipe´ a connu deux departs´ celui d’Emmanuel Lebhar (CR CNRS) qui a d’abord quitte´ le LIAFA pour le laboratoire CNRS du Chili et ensuite le CNRS, Nicolas Trotignon (CR CNRS) en 2011 pour le LIP. En conclusion, composee´ en janvier 2007 de 8 membres, l’equipe´ a et´ e´ fortement renforcee´ et compte maintenant 14 permanents ce qui lui donne un formidable potentiel scientifique. En effet, memeˆ si chaque chercheur de l’equipe´ possede` un domaine de recherche qui lui est propre, l’un des atouts principaux de l’equipe´ reside´ dans le partage des thematiques´ gen´ erales´ et les discussions a` l’issue du seminaire´ debouchent´ souvent sur des publications communes.

79 CHAPITRE 1. RAPPORT SCIENTIFIQUE : ALGORITHMES DISTRIBUES´ ET GRAPHES

1.1.2 Themes` de recherche

Algorithmique des graphes. Dans de nombreux domaines tels que la chimie, la biologie, les reseaux´ de tel´ ecommunications´ ou encore les reseaux´ sociaux, des modeles` a` base de graphes sont utilises´ quotidiennement en recherche. De memeˆ les graphes constituent des outils importants et tres` utilises´ de modelisation´ pour l’informatique elle-meme.ˆ En effet malgre´ la simplicite´ apparente de leur definition,´ les graphes capturent une large part de la complexite´ algorithmique. Il est donc tres` important de bien comprendre la structure des graphes et en particulier les decompositions´ combinatoires afin d’utiliser des modelisations´ pertinentes a` base de graphes (i.e. des modelisations´ sur lesquelles les algorithmes de resolution´ sont efficaces). Ainsi les recherches de l’equipe´ sur l’algorithmique des graphes ont deux objectifs principaux : le premier concerne la comprehension´ de la complexite´ structurelle des graphes via des decompositions´ de graphes et les invariants de graphes associes,´ tandis que le deuxieme` est centre´ sur la conception d’algorithmes efficaces sur les graphes memeˆ de tres` grande taille et l’etude´ des outils algorithmiques necessaires.´ Sur ces themes` l’equipe´ collabore reguli´ erement` avec D. Corneil (Toronto), F. Dragan (Kent, USA), M. C. Golumbic (Haifa), B. Reed (Montreal),´ J. L. Szwarcfiter (Rio) et Y. Wu (Shanghai) . . . Tolerance´ aux pannes. De l’Internet aux ordinateurs multi-coeurs, la plupart des applications peuvent etreˆ consider´ ees´ comme des applications distribuees´ et doivent gerer´ la concurrence, la synchronisation et la communication entre les diverses entites´ qui les composent. Ces applications doivent etreˆ robustes dans le sens ou` le service rendu doit pouvoir etreˆ assure´ memeˆ en presence´ de defaillances´ de certains composants. Rappelons qu’un des problemes` essentiels est le fait qu’il est impossible de realiser´ le consensus entre des processus asynchrones des` que l’un de ces processus peut tomber en panne. D’une maniere` gen´ erale,´ ce resultat´ d’impossibilite´ est central et defini´ une frontiere,` differente´ de celle de la calculabilite´ classique, entre ce qui est possible et ce qui ne l’est pas. Nos recherches ont pour objectif de contourner ce resultat´ d’impossibilite´ pour realiser´ des applications tolerantes´ aux pannes. Sur ce theme,` l’equipe´ collabore au sein des ANR et par des publications avec le LRI, le Lip6 et Asap (INRIA- Rennes) et collabore reguli´ erement` avec M. Aguilera (Microsoft USA), R. Guerraoui (EPFL), S. Toueg (U. Toronto), E. Gafni (UCLA), ... Protocoles distribues´ pour les reseaux.´ La conception de protocoles distribues´ pour les reseaux´ souleve` a` la fois des problemes` d’algorithmique distribuee´ et de conception de structures de donnees´ distribuees,´ voire les deux en memeˆ temps. Si le probleme` roi reste celui du routage, il est relie´ a` de nombreux problemes` fondamentaux comme la conception d’etiquetage´ de distances, la coloration, le calcul de spanner, etc... Les domaines d’applications des travaux de l’equipe´ ont principalement trait a` la conception de protocoles pour Internet ou les reseaux´ pair-a-pair,` a` l’analyse de differents´ types de reseaux´ sociaux (graphe du web, petits mondes, etc. . . ) et a` la resolution´ de problemes` algorithmiques issus de la bio-informatique. On vise particulierement` a` visiter l’interface entre les solutions theoriques´ connues et les contraintes de l’algorithmique des grands reseaux.´ Sur ce theme,` l’equipe´ collabore au sein des ANR et par des publications avec le LRI, le LIP6 et le LABRI et collabore reguli´ erement` avec S. Kutten(Technion), A. Pelz (Ottawa), D. Peleg (Weismann), S. Rajsbaum (UNAM), R. Wattenhofer (ETZH),...

1.2 Exemples de resultats´ signiﬁcatifs

Theorie´ structurelle des graphes et coloration. L’equipe´ a obtenu plusieurs avancees´ interessantes,´ comme la resolution´ d’une conjecture de B. Reed sur la coloration fractionnaire [Ser10a], la solution asymptotique de la conjecture de Griggs et Yeh [HRS12], l’avancee´ sur la conjecture de Bermond et Thomassen [LPS09] ou encore les resultats´ sur la coloration circulaire des graphes cubiques [KMMS10] et ceux des graphes de largeur d’arborescence bornee´ [KKSS10]. L’equipe´ a aussi developp´ e´ des axes plus mathematiques.´ Ils concernent d’abord la theorie´ extremale´

80 CHAPITRE 1. RAPPORT SCIENTIFIQUE : ALGORITHMES DISTRIBUES´ ET GRAPHES des graphes avec notamment l’utilisation des algebres´ de drapeaux pour produire des avancees´ sur des questions extremales´ de graphes, mais aussi des problemes` de geom´ etrie´ discrete` [KMS12]. Aspects algorithmiques des decompositions´ de graphes. L’equipe´ a mis un point final (au moins pour elle) a` l’algorithmique de la decomposition´ modulaire des graphes en proposant un algorithme lineaire´ tres` simple [TCHP08]. Les familles partitives qui sont sous-jacentes a` la decomposition´ modulaire se retrouvent naturellement dans la decomposition´ de graphes en arbres, et notamment dans la decomposition´ en coupes, introduite par Cunningham en 1982, qui est une gen´ eralisation´ de la decomposition´ modulaire. A partir du travail de Elias Dahlhaus en 2000 [J. Algorithms 36(2) : 205-240], on a mis en evidence´ une sous-routine de l’algorithme principal qui permet de calculer des classes de recouvrement d’ensembles [CHLMRR08] et finalement reussi´ a` construire un algorithme lineaire´ comprehensible´ pour la decomposition´ en coupes qui emprunte certaines intuitions a` Dalhlaus mais les complemente´ avec de nouvelles. Ces travaux sont publies´ dans SIAM Journal of Discrete Mathematics [CMR12]. Par ailleurs on a etudi´ e´ l’algorithmique des decompositions´ en 2-join et le calcul des paires homogenes,` mais helas´ dans ces cas on est encore loin des algorithmes optimaux [HMM12]. Reseaux´ phylogen´ etiques´ et graphes cordaux. On a obtenu la solution d’une conjecture de phylogenie,´ vieille de 20 ans de M. Steels, en fait un resultat´ d’impossibilite´ [HT11]. Ce resultat´ fut obtenu en traduisant le probleme` sur la classe des graphes cordaux et en utilisant notre connaissance de la structure de ces graphes [HS09c; HS11; HS12]. Concernant les applications a` la biologie, nous avons etudi´ e´ dans la cadre de la these` de Thu Hien To, des problemes` lies´ a` des gen´ eralisations´ de la phylogenie,´ lorsque la hierarchie´ recherchee´ n’est plus un arbre mais possede` quelques cycles. Enfin depuis 2010, l’equipe´ a demarr´ e´ une collaboration avec deux biologistes E. Bapteste et P. Lopez du Laboratoire (SAE) Systematique,´ Adaptation, Evolution UMR CNRS 7138 et Universite´ Paris 6. Cette collaboration porte sur l’analyse des reseaux´ phylogen´ etiques´ et certaines des questions traitees´ dans la these` de Thu Hien To en sont issues. Cette collaboration a obtenu le soutien de la ville de Paris (2 annees´ de post-doctorat). Detecteur´ de defaillances.´ Les detecteurs´ de defaillances,´ introduits par Chandra et Toueg (J. ACM 96), sont des oracles distribues´ qui ne dependent´ que des defaillances´ des processus. En determinant´ pour un probleme` donne´ le detecteur´ de defaillances´ minimal, on determine´ l’information sur les defaillances´ necessaire´ et suffisante pour resoudre´ ce probleme.` Nous avons contribue´ de maniere` signi- ficative a` determiner´ le detecteur´ minimal de plusieurs primitives essentielles [DGFGT08; DGFGT09b; DGFT09c; DGFT11]. En particulier, Chandra, Hadzilacos et Toueg (J. ACM 96) avaient decouvert´ le plus faible detecteur´ de defaillances´ pour resoudre´ le consensus dans un systeme` par message, si une majorite´ de processus sont corrects, laissant la question ouverte dans le cas d’un nombre quelconque de pannes. Quinze ans plus tard, nous avons apporte´ une reponse´ a` cette question [DGFG10], ce resultat´ a et´ e´ publie´ dans J. ACM en 2010. Spanners et routage. Le calcul de spanner constitue l’un des problemes` fondamentaux lies´ a` celui du routage. En effet, toutes les constructions connues de routage compact resolvent´ de maniere` implicite ce probleme` plus simple. Un spanner est un sous-graphe preservant´ les distances (voir Peleg et Ullman [PODC’87]). Il existe un compromis entre la taille du spanner et son etirement´ (c’est-a-dire` dans quelle mesure les distances sont etir´ ees´ dans le spanner en comparaison avec celles du graphe). Dans [DGPV08] et [DGPV09], nous proposons des algorithmes distribues´ de calcul de spanner de petite taille avec faible etirement.´ Ceci peut-etreˆ consider´ e´ comme un premier pas vers un algorithme distribue´ de routage compact [FLV08]. Dans le cadre des etiquetages´ informatifs [CFIKP09], nous avons resolu´ un probleme` ouvert depuis plus de 20 ans [FK10a]. Petits-mondes. Les experiences´ en sciences sociales de Milgram dans les annees´ 60 ont non seulement rev´ el´ e´ que les gens etaient´ a` quelques poignees´ de mains les uns des autres (en moyenne 6) mais surtout qu’ils etaient´ capables de trouver des chemins tres` courts en se basant uniquement sur leur vision extremementˆ parcellaire du reseau´ social. Kleinberg (2000) a propose´ un premier modele` algorithmique

81 CHAPITRE 1. RAPPORT SCIENTIFIQUE : ALGORITHMES DISTRIBUES´ ET GRAPHES base´ sur une grille permettant de comprendre ce phenom´ ene.` L’equipe´ a poursuivi ses travaux sur ce domaine en etendant´ et precisant´ considerablement´ son modele` et en obtenant ainsi une connaissance bien plus profonde du phenom´ ene` des petits-monde et de ses applications au domaine de l’informatique distribuee.´ On a demontr´ e´ que l’on pouvait transformer n’importe quel graphe en petit-monde par l’ajout d’un unique lien aleatoire´ par nœud : [FG08; FG10b; FGKLL07; FGKLL09] pour les graphes arbitraires, [LS08] pour les graphes admettant un plongement dans un espace euclidien de faible distor- sion. La borne etablie´ par [FG10b] realise´ par ailleurs la borne inferieure´ prec´ edemment´ etablie´ dans [FLL10a]. Nous avons egalement´ demontr´ e´ que la loi sur le degre´ des nœuds a un impact significatif sur les performances du routage [FG09]. La plupart des resultats´ presentent´ des bornes inferieures´ et superieures´ en adequation.´ Nous avons egalement´ propose´ un cadre d’analyse permettant de caracteriser´ totalement les algorithmes de recherche optimaux dans les modeles` de Kleinberg [GS11]. Nous avons egalement´ propose´ et analyse´ le premier modele` dynamique naturel engendrant un petit-monde combi- nant marches aleatoires´ et oubli [CFL08a]. Nous avons enfin propose´ une technique pour extraire les liens longue-distance d’un graphe et valider ainsi le modele` de Kleinberg [FLL10b]. Reseaux´ sociaux. Avec la multiplication des donnees´ d’interactions representables´ sous forme de graphes a` de tres` larges echelles´ (millions, milliards de sommets), l’analyse de la structure et de la dynamique globales de tels graphes est au cœur d’une intense activite´ de recherche interdisciplinaire. A cette echelle,´ un defi´ majeur consiste a` depasser´ le stade de l’analyse globale pour produire une connaissance utile sur les individus qui constituent ces reseaux.´ En effet [LPBSDHV08; RP11] montrent l’importance des dynamiques locales dans la formation des liens et qu’il est possible d’identifier, au moyen de propriet´ es´ structurelles sur les graphes, et avec des algorithmes performants [SP09a], plusieurs gammes de comportements individuels [BCPP09; PPBCP08; RP11; SSP12]. Distribution de contenu. La distribution de contenu via le pair-a-pair` (P2P) est une solution efficace a` des problemes` industriels qui soulevent` de nombreuses questions theoriques.´ En utilisant le concept de source (des pairs qui possedent` le contenu a` distribuer et qui aident a` sa dissemination),´ [Mat11] montre que la bande passante disponible par utilisateur pouvait etreˆ ajustee´ pour repondre´ a` peu pres` a` toutes les requetes.ˆ Un brevet [MP08], est depos´ e´ sur cette methode´ de distribution. Dans [BMMPV08; BMMPV09a; BMMPV09b], on a repondu´ en partie aux problemes` poses´ par la video´ a` la demande tels que : a` quel utilisateur se connecter pour visionner (sans delai´ de pre-chargement)´ un film stocke´ ? Ou` stocker les films ? En combien d’exemplaires ?

1.3 Animation scientiﬁque, rayonnement, prix et recompenses´

Comme en temoigne´ le nombre et la qualite´ des chercheurs invites´ et des co-auteurs, le reseau´ scientifique de l’equipe´ tant international que national est etendu´ et d’une tres` grande qualite.´ Les membres de l’equipe´ participent a` de nombreux comites´ de programme (dont la presidence´ du comite´ de programme de PODC en 2011) et comites´ de pilotage dans des conferences´ de ref´ erence´ de leurs thematiques´ (PODC, DISC, WG, STACS). Ils participent aussi activement a` l’animation scientifique française par le biais des ANR et la participation continue a` des comites´ de programme de conferences´ nationales (Algotel, Jdir), mais aussi un soutien a` la communaute´ Algerienne´ (COSI conference´ annuelle sur l’optimisation et les systemes` d’information). Jean-Sebastien´ Sereni est a` l’initiative et coresponsable de STRUCO, laboratoire europeen´ associe´ du CNRS dont les themes` principaux sont la theorie´ des graphes, l’informatique theorique´ et la verification.´ L’equipe´ de recherche de ce LEA comprend egalement´ des chercheurs issus d’autres instituts, comme l’IHESS et l’ENS (a` Paris), le projet Mascotte (Sophia Antipolis), l’universite´ de Boheme` de l’ouest (Plzen) et celle de Brno. L’equipe´ est tres` fiere` de plusieurs distinctions obtenues ces dernieres` annees,´ en particulier de la Medaille´ d’Argent 2012 pour l’Institut des sciences informatiques et de leurs interactions (INS2I) qui

82 CHAPITRE 1. RAPPORT SCIENTIFIQUE : ALGORITHMES DISTRIBUES´ ET GRAPHES a et´ e´ decern´ ee´ a` Pierre Fraigniaud, ainsi que trois prix du ”meilleur article” dont deux dans DISC une conference´ tres` selective´ en algorithmique distribuee´ et enfin du prix de l’article le plus cite´ dans TCS pour la periode´ 2005-2010. L’equipe´ tient a` la vulgarisation de ses recherches. Laurent Viennot est editeur´ scientifique de )i(nterstices, un site de vulgarisation porte´ par Inria, le CNRS et les universites,´ et des membres de l’equipe´ ont ecrit´ plusieurs articles dans cette revue ainsi que dans d’autres magasines de vulgarisation (Le Monde supplement´ Sciences & Techno, Sciences & Avenir, La recherche, L’explosion des mathematiques).´ Tous les ans a` la feteˆ de la sciences on propose des ateliers et des conferences.´ Les recherches sur les reseaux´ sociaux ont permis d’etablir´ des liens etroits´ avec Linkfluence et Oran- geLabs (une these` CIFRE a et´ e´ realis´ ee´ avec chacun de ces partenaires) et de participer a` la startup Move&Play sur le partage de donnees´ personnelles. Un brevet [MP08] sur l’utilisation d’un ensemble de clients privilegi´ es´ pour une diffusion collaborative a et´ e´ depos´ e´ en 2008.

1.4 Fonctionnement interne

L’equipe´ partage avec les autres equipes´ les personnels administratifs et techniques (4 personnes) du LIAFA et avec d’autres equipes´ Inria un personnel administratif (non present´ au LIAFA). La plupart des membres de l’equipe´ fait partie de l’equipe´ projet INRIA Gang (10 membres sont communs, 1 chercheur est uniquement a` Gang, 2 chercheurs et 1 enseignant-chercheur sont uniquement au LIAFA). L’equipe´ projet Gang a et´ e´ favorablement evalu´ ee´ en mars 2012, lors de l’evaluation´ de la thematique´ INRIA Reseaux´ et Systeme.` Cette affiliation INRIA, nous permet de collaborer naturellement avec les autres equipes´ projet du theme` Reseaux´ et Systeme` et de ben´ eficier´ d’une bonne infrastructure technique. L’equipe´ a un seminaire´ hebdomadaire qui couvrent toutes ses thematiques.´ Des sous groupes se retrouvent dans des groupes de travail plus pointus. Celui sur la decomposition´ de graphes qui a et´ e´ actif pendant deux ans a particulierement` bien reussi´ puisqu’il a donne´ lieu, entre autres, a` une publication dans SIAM Journal of Discrete Mathematics. Les membres de l’equipe´ sont tres` actifs dans les demandes de financement sur projet tant nationaux qu’internationaux et ils ont un bon taux de reussite.´ L’equipe´ ben´ eficie´ de plus d’un excellent environnement : l’Ecole Doctorale Science mathematique,´ la fondation Sciences Math de Paris, l’Universite´ Paris Diderot, l’Ile de France, la ville de Paris ainsi que l’ANR, le CNRS et INRIA (via notre equipe´ Gang) et a aussi des liens avec des entreprises (OrangeLabs, LinkFluence, Thales). L’equipe´ s’adresse a` toutes ces sources pour financer des doctorants, des post doctorants, des chercheurs invites´ et des missions en s’organisant afin que ses demandes ne rentrent pas en concurrence. On a ainsi obtenu par ces differentes´ sources l’equivalent´ de 15 annees´ de Post Doc, 34 mois de chercheurs invites´ et 14 financements de theses` (dont 2 theses` CIFRE). Depuis 2007, les ressources sur projet ont augmente´ de plus de 100% et on a ainsi pour 2012 environ 300Ke de financement. Les financements associes´ a` un projet vont naturellement aux participants du projet. Jusqu’a` maintenant les financements obtenus couvrent les besoins de chaque membre de l’equipe.´

1.5 Formation par la recherche

L’algorithmique distribuee´ et la theorie´ des graphes forment un ensemble de quatre cours coherents´ dans le master recherche en informatique (ex MPRI). Les enseignants de l’equipe´ participent a` d’autres cours de niveau Master 2 dans d’autres universites´ et dans d’autres grandes ecoles´ (Centrale, ENPC, ENS Lyon, INSA, X). Durant la periode´ concernee´ par ce rapport, 13 etudiants´ en stage de M2 ont et´ e´ accueillis, 14 doctorants ont commence´ une these` et 11 theses` ont et´ e´ soutenues dans l’equipe.´

83 CHAPITRE 1. RAPPORT SCIENTIFIQUE : ALGORITHMES DISTRIBUES´ ET GRAPHES

Toutes les theses` sont ﬁnancees´ : grandes ecoles,´ allocation doctorale du ministere,` projet (ANR, Ile de France), CIFRE... La duree´ moyenne d’une these` est de 3,5 ans. En plus des dispositifs mis en place par l’Ecole Doctorale et le LIAFA (seminaire´ des doctorants, ecole´ de printemps), le seminaire´ de l’equipe,´ les groupes de travail, les nombreux chercheurs invites,´ les series´ de cours organises´ sur un theme` donne´ (le lemme de regularit´ e´ de Szemeredi,´ Structure des graphes epars´ (i.e. la recente´ theorie´ de J. Nesetˇ rilˇ et P. Ossona de Mendez), preuve complete` du theor´ eme` PCP...) contribuent a` la formation des doctorants. Enﬁn, les doctorants sont impliques´ dans les projets ANR et participent aux journees´ de travail de ceux- ci ce qui leur permet de se former et de presenter´ leurs travaux tout en s’integrant´ au reseau´ de recherche national.

84 Chapitre 2

Fiche resum´ e´ : Algorithmes Distribues´ et Graphes

Intitule´ de l’unite´ : LIAFA, UMR 7089 Nom du Directeur de l’unite´ : Pierre Fraigniaud Nom du responsable de l’equipe´ : Carole Delporte-Gallet

2.1 Effectifs

2007 : 3 chercheurs (2 CNRS, 1 INRIA), 5 enseignants-chercheurs, 6 postdoc, 7 doctorants. 2012 : 7 chercheurs (5 CNRS, 2 INRIA), 7 enseignants-chercheurs, 2 postdoc, 9 doctorants. Personnels qui ont quitte´ l’equipe´ : Emmanuel Lebhar (septembre 2009, 32 mois), Nicolas Trotignon (de septembre 2008 a` mars 2011, 31 mois). Recrutement : 2007 : Carole Delporte (Changement d’equipe),´ Hugues Fauconnier (Changement d’equipe),´ Amos Korman (CR2), Mathieu Rafﬁnot (Mutation). 2008 : Nicolas Schabanel (Muta- tion), Jean-Sebastien´ Sereni´ (CR2), Nicolas Trotignon (CR1). 2010 : Fabien Mathieu (Chercheur CDD INRIA). 2.2 Production scientiﬁque

Decomposition´ de graphes. Notre equipe´ a une longue (et fructueuse) tradition de recherche sur la thematique´ de la decomposition´ de graphes [CHLMRR08; HP10]. Nous avons atteint deux objectifs majeurs : un algorithme lineaire´ simple pour la decomposition´ modulaire [TCHP08] et un algorithme lineaire´ pour la decomposition´ en coupes [CMR12]. Detecteurs´ de defaillances.´ Nous avons realis´ e´ un important travail sur les plus faibles detecteurs´ de defaillances´ [DGFGT08; DGFT09b; DGFT09c; DGFT11] et clotˆ un probleme` ouvert depuis plus de 20 ans pour le consensus [DGFG10]. Petits-mondes. Nous avons eu un roleˆ moteur dans l’analyse des graphes petits-mondes de Klein- berg [CFL08a; FGKLL07; FGKLL09; FKL10; FLL10a; FLL10b; LS08] et sans doute clotˆ ce sujet en proposant un cadre d’analyse tres` simple et en etablissant´ les performances optimales exactes des algorithmes de routage distribues´ pour ce modele` [GS11]. Theorie structurelle des graphes et coloration. Nous avons obtenu plusieurs avancees´ signiﬁcatives sur la coloration des graphes [KKSS10; KMMS10; LPS09; Ser10a], et apporte´ une solution asymptotique a` la conjecture de Griggs et Yeh [HRS12]. Spanner et routage. Nous avons propose´ plusieurs algorithmes efﬁcaces pour le calcul distribue´ de spanners avec faible etirement´ [DGPV08; DGPV09] et des algorithmes distribues´ de routage compact [FLV08]. Dans le cadre des etiquetages´ informatifs [CFIKP09], nous avons resolu´ un probleme` ouvert depuis plus de 20 ans [FK10a].

85 CHAPITRE 2. FICHE RESUM´ E´ : ALGORITHMES DISTRIBUES´ ET GRAPHES

2.3 Bilan quantitatif 2.3.1 Publications Journaux : 117 ; Conf. Int. avec CL : 133 ; Conf. Int. Inv. : 19. [CMR12] Pierre Charbit, Fabien Montgolfier, Mathieu Raffinot. “Linear Time Split Decomposition Revisited”. SIAM Journal on Discrete Mathematics 26.2 (2012), pp. 499–514. DOI: 10.1137/10080052X. URL: http://link.aip.or g/link/?SJD/26/499/1 [DGFG10] Carole Delporte-Gallet, Hugues Fauconnier, Rachid Guerraoui. “Tight failure detection bounds on atomic object implementations.” J. ACM 57.4 (2010) [GS11] George Giakkoupis, Nicolas Schabanel. “Optimal path search in small worlds: dimension matters.” In: Proceedings of the 43rd ACM Symposium on Theory of Computing, STOC 2011, San Jose, CA, USA, 6-8 June 2011. ACM, 2011, pp. 393–402 [HRS12] Fred´ eric´ Havet, Bruce A. Reed, Jean-Sebastien´ Sereni. “Griggs and Yeh’s Conjecture and L(p, 1)-labelings.” SIAM J. Discrete Math. 26.1 (2012), pp. 145–168 [FK10a] Pierre Fraigniaud, Amos Korman. “An optimal ancestry scheme and small universal posets.” In: Proceedings of the 42nd ACM Symposium on Theory of Computing, STOC 2010, Cambridge, Massachusetts, USA, 5-8 June 2010. ACM, 2010, pp. 611–620 2.3.2 Logiciels, brevets, rapports, etc. Brevet ”Utilisation d’un ensemble de clients privilegi´ es´ pour une diffusion collaborative de contenu” [MP08]. Habilitation a` Diriger des Recherches : 1. Christophe Prieur, Reseaux´ sociaux, algorithmes, identites´ , automne 2012. 2. Nicolas Schabanel, Systemes` complexes & Algorithmes, 26 fevrier´ 2010. 3. Nicolas Trotignon, Structure des classes de graphes definies´ par l’exclusion de sous-graphes induits, 15 decembre´ 2009. 2.3.3 Rayonnement 1.M edaille´ d’Argent 2012 de l’Institut des sciences informatiques et de leurs interactions (INS2I- CNRS). Prix de l’article le plus cite´ de TCS pour la periode´ 2005-2010 (2010) et 3 prix du ”meilleur article” (DISC (2009 et 2011), ICDCN (2009)). 2. Co-direction, avec l’Universite´ de Charles de Prague, du LEA Laboratoire Franco-Tcheque´ sur la theorie´ des graphes, l’informatique theorique´ et la verification´ (STRUCO). 3. Large reseau´ scientifique international : invitation de chercheurs etrangers´ (34 mois cumules),´ 57 participations a` des comites´ de programme, presidence´ du comite´ de programme de PODC, 10 projets bilateraux,´ Projet Europeen COST Dynamo (36 partenaires). 4. Acteur dynamique de la recherche française : 13 participations aux comites´ de programme nationaux, co-presidence´ du comite´ de programme d’Algotel, 9 projets ANR. 5. Trois quarts des membres de l’equipe´ sont membres de l’equipe´ projet INRIA GANG. 2.3.4 Interactions de l’equipe´ avec son environnement 1. Contrat avec le musee´ des science de Santiago du Chili (Museo Interactivo Mirador) pour le developpement´ et la realisation´ de l’ attraction ”Fenetreˆ sur l’infini”. 2. Participation a` la creation´ de la startup Move&Play sur le partage de donnees´ personnelles. (laureate´ 2007 et 2008 du concours national OSEO d’aide a` la creation´ d’entreprises de technologies innovantes). 3.R ealisation´ de deux services web de visualisation lies´ a` la couverture mediatique´ de la campagne presidentielle´ (l’un laureat´ du concours Dataviz 2012 de Google France, et l’autre integr´ e´ sur lemonde.fr). 2.3.5 Actions de formation 1. Masters de Paris Diderot dont “Master de Recherche en Informatique (ex MPRI)” (4 cours). 2.S erie´ de cours a` destination des chercheurs sur la ”Preuve complete` du theor´ eme` PCP”. 3. Cours a` l’Ecole Polytechnique, ENPC, ENS Lyon, Centrale Paris, INSA Lyon.

86 Chapitre 3

Executive Summary : Distributed Algorithms and Graphs

Name : LIAFA, UMR 7089 Leader : Pierre Fraigniaud Leader of the team : Carole Delporte

3.1 Members

2007 : 3 researchers (2 CNRS, 1 INRIA), 5 teaching researchers, 6 postdoc, 7 PhD students. 2012 : 7 researchers (5 CNRS, 2 INRIA), 7 teaching researchers, 2 postdoc, 9 PhD students. Persons who left the team : Emmanuel Lebhar (september 2009, 32 mo.), Nicolas Trotignon (from september 2008 to march 2011, 31 mo.). New members : 2007 : Carole Delporte (team change), Hugues Fauconnier (team change), Amos Kor- man (CR2), Mathieu Rafﬁnot (lab change). 2008 : Nicolas Schabanel (lab change), Jean-Sebastien´ Sereni´ (CR2), Nicolas Trotignon (CR1). 2010 : Fabien Mathieu (INRIA non-permanent researcher). 3.2 Scientiﬁc outcomes

Graph decompositions. Our team has a fruitful and longstanding research tradition in graph decomposition [CHLMRR08; HP10]. We have matched two major objectives : a simple linear time algorithm for modular decomposition [TCHP08] and a linear-time algorithm for cut decomposition [CMR12]. Failure detectors We have achieved an important work on the weakest failure detectors [DGFGT08; DGFT09b; DGFT09c; DGFT11] and answered a question on consensus which was open for 20 years [DGFG10]. Smallworlds. We have a leading role in the analysis of Kleinberg’s models for the smallworld phe- nomenon [CFL08a; FG08; FG09; FG10b; FGKLL07; FGKLL09; FLL10a; FLL10b; LS08]; in particular, we have provided a simple framework for the analysis the optimal performances of routing algorithms in this model [GS11]. Structural graph theory and Colouring. We have proposed several significant improvements on graph colouring [KKSS10; KMMS10; LPS09; Ser10a], and obtained an asymptotic solution to Griggs and Yeh’s conjecture [HRS12]. Routing. We have proposed efficient distributed algorithms for the computation of sparse spanners with low stretch [DGPV08; DGPV09]. Concerning informative labeling schemes, the most studied problem in the literature [CFIKP09] has finally been closed by the team in [FK10a].

87 CHAPITRE 3. EXECUTIVE SUMMARY : DISTRIBUTED ALGORITHMS AND GRAPHS

3.3 Quantitative assessment 3.3.1 Publications Journals : 117 ; Int. Conf. with PC : 133 ; Inv. Int. Conf. : 19. [CMR12] Pierre Charbit, Fabien Montgolfier, Mathieu Raffinot. “Linear Time Split Decomposition Revisited”. SIAM Journal on Discrete Mathematics 26.2 (2012), pp. 499–514. DOI: 10.1137/10080052X. URL: http://link.aip.or g/link/?SJD/26/499/1 [DGFG10] Carole Delporte-Gallet, Hugues Fauconnier, Rachid Guerraoui. “Tight failure detection bounds on atomic object implementations.” J. ACM 57.4 (2010) [GS11] George Giakkoupis, Nicolas Schabanel. “Optimal path search in small worlds: dimension matters.” In: Proceedings of the 43rd ACM Symposium on Theory of Computing, STOC 2011, San Jose, CA, USA, 6-8 June 2011. ACM, 2011, pp. 393–402 [HRS12] Fred´ eric´ Havet, Bruce A. Reed, Jean-Sebastien´ Sereni. “Griggs and Yeh’s Conjecture and L(p, 1)-labelings.” SIAM J. Discrete Math. 26.1 (2012), pp. 145–168 [FK10a] Pierre Fraigniaud, Amos Korman. “An optimal ancestry scheme and small universal posets.” In: Proceedings of the 42nd ACM Symposium on Theory of Computing, STOC 2010, Cambridge, Massachusetts, USA, 5-8 June 2010. ACM, 2010, pp. 611–620 3.3.2 Software, patents, reports, etc. Patent ”Using privileged users set for collaborative content broadcast” [MP08]. Habilitation a` Diriger des Recherches (Tenures) : 1. Christophe Prieur, Reseaux´ sociaux, algorithmes, identites´ , automn 2012. 2. Nicolas Schabanel, Systemes` complexes & Algorithmes, february 26, 2010. 3. Nicolas Trotignon, Structure des classes de graphes definies´ par l’exclusion de sous-graphes induits, december 15, 2009. 3.3.3 Influence of the team 1. 2012 Silver medal from the CNRS Institut des Sciences Informatiques et de leurs Interactions (INS2I-CNRS). Top cited article award in TCS for 2005-2010 (2010) and three best paper awards (DISC (2009 et 2011), ICDCN(2009)). 2. Co-direction (together with Charles University in Prague) of the LEA, the French-Czech lab on Graph Theory, Theoretical Computer Science and Verification (STRUCO). 3. Large international scientific network : invitations of foreign researchers (34 mo. in total), 57 participations to program committees, PODC program committee chair, 10 bilateral projects, European project COST Dynamo (36 partners). 4. Active actor on the French research stage : 13 participations to national program committees, co-chair of Algotel program committee, 9 ANR grants. 5. 3/4 of the team members belong also to the INRIA GANG team. 3.3.4 Interactions between the team and its environment 1. Financial agreement with Museo Interactivo Mirador (Santiago de Chile science museum) for the realization of the permanent interactive exhibition ”Encuentra el infinito”. 2. We have participated to the creation of a startup-up company on personal data sharing. The company has received grants in 2007 and 2008 from the national OSEO funding contest. 3. Realization of two visualization web services for the media coverage of the French presidential campaign (one won the Google France Dataviz 2012 competition and the other was integrated to the lemonde.fr website). 3.3.5 Teaching 1. Paris Diderot Masters, in particular “Master de Recherche en Informatique (ex MPRI)” (4 courses). 2. Series of lectures addressed to researchers ”Complete proof of the PCP Theorem”. 3. Lectures at the Ecole´ Polytechnique, ENPC, ENS Lyon, Centrale Paris, INSA Lyon.

88 Chapitre 4

Projet scientiﬁque : Algorithmes Distribues´ et Graphes

Le distribue´ a acquis une certaine maturite´ mais il prend aussi une importance croissante dans les nouvelles technologies et les usages actuels de l’informatique. Il se developpe´ dans plusieurs directions tant au sein des ordinateurs qu’au sein des grands reseaux´ tant sur des aspects techniques que sur des aspects sociaux. Ce phenom´ ene` devrait se renforcer et de nouveaux domaines de recherche emerger´ au cours des dix prochaines annees.´

4.1 Objectifs scientiﬁques

L’explosion du distribue´ ne permettra pas aux membres de l’equipe,´ dans sa composition actuelle, d’en couvrir tous les aspects. Par ailleurs, l’elargissement´ du spectre des recherches risque d’eloigner´ plus encore thematiquement´ ceux-ci. Cette evolution´ est amplifiee´ par le depart´ de Nicolas Trotignon auquel va s’ajouter celui de Jean-Sebastien´ Sereni qui a demande´ une mutation au LORIA pour rapprochement de conjoints 1. Ils travaillaient sur des thematiques´ relevant de la theorie´ des graphes. Il ne restera prochainement plus que deux membres ayant pour thematique´ principale la theorie´ des graphes or les interactions du reste de l’equipe´ avec ce theme` theorique´ (cf. les publications communes) etaient´ l’une des specificit´ es´ de notre equipe.´ Dans ces conditions (l’auto-evaluation´ du projet scientifique de l’equipe´ est resum´ e´ dans le diagramme MOFF Figure 4.1) l’equipe´ a identifie´ plusieurs defis´ scientifiques, detaill´ es´ ci dessous, sur lesquels elle va travailler dans les cinq prochaines annees.´ Ceux ci concernent des recherches fondamentales et appliquees´ d’algorithmique distribuee´ et de theorie´ des graphes ainsi que des recherches relevant de la bio-informatique. Ces dernieres` sont en continuite´ avec des travaux dej´ a` realis´ es´ (sous section 4.1.3) et des travaux debut´ es´ tout recemment´ (sous section 4.1.4).

4.1.1 Theorie´ de la calculabilite´ et de la complexite´ du calcul distribue.´

Le calcul distribue´ souleve` de nombreuses questions de calculabilite´ et de complexite.´ Par exemple, pour les problemes` lies´ aux calculs tolerants´ aux pannes, les resultats´ classiques d’impossibilite´ ne sont pas lies´ a` la puissance de calcul des processus. Ces resultats´ d’impossibilite´ ont une forme d’indecidabilit´ e´ qui est fondamentalement differente´ de celle du calcul sequentiel.´ De la memeˆ maniere,` dans le calcul reseau,´ la possibilite´ de resoudre´ localement certaines tachesˆ ne depend´ pas de la puissance de chacun des processus. L’objectif est d’etablir´ les fondements scientiﬁques d’une theorie´ de la calculabilite´ et de la complexite´ du calcul distribue.´ Une difﬁculte´ a` laquelle nous devons faire face est de concilier les deux sous communautes´ du calcul

1. Jean-Sebastien´ Sereni est affecte´ au LORIA a` partir du 1er janvier 2013.

89 CHAPITRE 4. PROJET SCIENTIFIQUE : ALGORITHMES DISTRIBUES´ ET GRAPHES

INTERNE

–risque d’

–affaiblissement largeur du spectre de la th

th eclatement´ du fait de la de d eorie´ des graphes

eparts´

ematique´ Faiblesses a` la suite – INRIA-Gang – Fortnationales tissu de collaborations et internationales Forces NEGATIVE F F O M

POSITIVE Opportunit –Qualit –Importance croissante du

distribu e´ de l’environnement es technologies modernes ´ Menaces

e´ dans les

ependance´ importante –D des ﬁnancements en provenance de l’ANR

EXTERNE

FIGURE 4.1 – Analyse MOFF du projet scientiﬁque

90 CHAPITRE 4. PROJET SCIENTIFIQUE : ALGORITHMES DISTRIBUES´ ET GRAPHES distribue´ : calcul tolerant´ aux pannes et calcul reseau,´ qui ont chacune developp´ e´ des modeles` de calcul distribue.´ La premiere` est plus interess´ ee´ par les problemes` lies´ a` l’asynchronisme et la deuxieme` par les problemes` lies´ au reseau.´ Les differents´ travaux auxquels s’attaquent ces deux communautes´ impliquent differents´ objectifs : la calculabilite´ est au centre de la premiere` tandis que la complexite´ est au centre de la seconde. L’equipe´ avec des specialistes´ des deux courants principaux du calcul distribue´ est particulierement` bien armee´ pour relever ce deﬁt.´ Pour atteindre notre objectif, on se propose de realiser´ les tachesˆ suivantes :

– Formaliser les problemes` oui/non pour lesquels les calculs distribues´ seront interpret´ es´ comme une sortie binaire unique : oui ou non, dans le contexte du calcul distribue.´ Ces problemes` aspirent a` jouer pour le calcul distribue´ un roleˆ analogue a` celui joue´ par des problemes` de decision´ dans le contexte du calcul sequentiel.´ – Revisiter les differentes´ notions d’oracles, qu’ils soient explicites (par exemple, des detecteurs´ de defaillances)´ ou implicites (par exemple, des informations a priori) utilises´ dans le calcul distribue,´ pour les specifier´ en terme de classes de decidabilit´ e/complexit´ e´ basees´ sur des oracles. – Comparer des classes de complexite´ et de decidabilit´ e´ correspondant a` la capacite´ de resoudre´ des problemes` oui/non, ou de resoudre´ ces problemes` dans un certain temps. Cette tacheˆ exige d’introduire de nouvelles notions de reductions´ entre problemes.` – Identifier l’impact du non determinisme´ sur le calcul distribue.´ En particulier, nous voulons mieux comprendre le manque apparent d’impact du non determinisme´ dans le contexte du calcul tolerant´ aux pannes, apparemment en contraste avec l’impact enorme´ du non determinisme´ dans le contexte de calcul reseau.´ Egalement, nous pensons que le non determinisme´ permettra la comparaison de classes de complexite´ definies´ dans le contexte de tolerance´ aux pannes avec des classes de complexite´ definies´ dans le contexte du calcul de reseau.´ – Enfin on etudiera´ des nouveaux paradigmes de calcul, y compris, le calcul distribue´ quantique (these` Eger Arfaoui) et la theorie´ algorithmique des jeux (par exemple, des jeux de construction de reseau).´

On aura donc a` faire face et a` resoudre´ plusieurs problemes` extremementˆ stimulants. Pour se faire, on a pris soin de rassembler dans l’ANR DISPLEXITY (ANR Blanche 2012-2016) outre pres´ de la moitie´ des chercheurs de notre equipe´ des chercheurs franc¸ais choisis parmi les leaders du calcul distribue´ (ASAP INRIA Rennes, LABRI Bordeaux). On compte aussi sur notre reseau´ international (E. Gafni (UCLA), R. Guerraoui (EPFL), A. Pelz (Ottawa), D. Peleg (Weismann), S. Rajsbaum (UNAM), S. Toueg (Toronto)...) pour mener a` bien ce projet. Le succes` de ces recherches aboutira a` un accroissement signiﬁcatif de la connaissance actuelle et de la comprehension´ du calcul distribue.´

4.1.2 Grands reseaux´

Algorithmique du Pair-a-Pair` La distribution de contenu via le pair-a-pair` (P2P) est une solution efficace a` des problemes` industriels qui souleve` de nombreuses questions theoriques.´ Depuis les premieres` applications de diffusion de fichiers (filesharing) bien des progres` ont et´ e´ faits. Ainsi on peut mettre en oeuvre de la video´ a` la demande (Vod) via un reseau´ P2P. Un tel service est en effet possible en utilisant les capacites´ de stockage et la connectivite´ des modems evolu´ es´ (”boxs”). Sa mise en oeuvre pose des problemes` tels que : a` quel utilisateur se connecter pour visionner (sans delai´ de pre-chargement)´ un film stocke´ ? Ou` stocker les films ? En combien d’exemplaires ? Augmenter le nombre de copies ameliore´ la qualite´ du service, mais diminue le nombre maximal de films offerts. Nous avons dej´ a` montre´ qu’un nombre constant de copies

91 CHAPITRE 4. PROJET SCIENTIFIQUE : ALGORITHMES DISTRIBUES´ ET GRAPHES

(independant´ du nombre d’utilisateurs) suffit. Mais la mise en oeuvre d’un tel mecanisme´ souleve` de nouvelles questions en particulier a` qui se connecter (arbitrage entre la longueur et la largeur des arbres de diffusion a` construire), la tolerance´ aux pannes ( la deconnexion´ impromptue d’un pair risquant de destabiliser´ le flux), l’incitation a` la cooperation,´ etc... Les mecanismes´ ”a` la bittorrent” d’incitation a` la cooperation´ par echange´ de bande passante (tit-for- tat algorithm) soulevent` d’interessants´ problemes.` Les mecanismes´ para-economiques´ mis en jeux ne sont pas le theme` de l’equipe´ ; par contre ils nous ont amene´ a` l’etude´ des systemes` de pref´ erences.´ La donnee´ est un ensemble d’acteurs pouvant tirer profit de collaborations mutuelles, mais avec des capacites´ limites.´ Etant donne´ l’utilite´ attendue de chaque collaboration, et les connaissances partielles, il faut determiner´ qui collaborera avec qui. C’est une extension de la theorie´ des mariages (Gale Shapley) dont l’etude´ peut encore se rev´ eler´ tres` riche. Ce travail se fait en lien etroit´ avec l’equipe-projet´ INRIA Gang, dont sont membres toutes les personnes du LIAFA impliquees.´ Des contacts sont etablis´ avec la start-up Cleverscale (fondee´ par Anh-Tuan Gai qui a travaille´ avec l’equipe´ durant son doctorat), s’interessant´ aux reseaux´ de distribution de contenu (CDN). Modelisation´ et algorithmique des reseaux´ sociaux L’etude´ des reseaux´ sociaux sur le web est un des grands enjeux techniques et sociaux des annees´ a` venir. Tout d’abord, l’evolution´ du web est aujourd’hui tournee´ vers les mecanismes´ de recommandation en temps reel´ portes´ par les reseaux´ sociaux. Or, les outils algorithmiques en la matiere` sont encore balbu- tiants et obscurs. Par ailleurs, etudier´ l’evolution´ rapide des pratiques de sociabilite´ en ligne necessite´ d’enrichir par de nouvelles methodes´ la recherche en sciences sociales. Ces deux questions sont au cœur du projet interdisciplinaire Algopol (ANR Contenu et interactions, 2012–2015). Sur le plan des methodes,´ la mise au point d’algorithmes alternatifs tels que des algorithmes de streaming, pour les calculs de motifs, semble une piste tres` prometteuse compte tenu de la structure tres` locale des reseaux´ sociaux. Durant ces dix dernieres` annees,´ un tres` grand nombre de donnees´ ont et´ e´ collectees´ sur la dynamique de reseaux´ de natures tres` differentes´ (Facebook, Twitter, contacts dans les hopitaux, ecoles,´ conferences,´ etc.). Durant le PEPS DynaDraw, on a demontr´ e´ que l’algorithmique standard echoue´ a` capturer la nature des graphes dynamiques : l’approche en-ligne est souvent trop pessimiste pour obtenir des resultats´ probants et inversement, l’application d’algorithmes hors-ligne a` chaque pas de temps conduit a` des solutions instables au cours du temps (principalement a` cause de la faible densite´ de ces graphes a` chaque instant). En connaissant l’ensemble de la dynamique, l’objectif est de rechercher une solution stable dans le temps reagissant´ aux changements brutaux du reseau.´ Nous projetons d’etudier´ dans un premier temps le probleme` de la partition en clusters d’un graphe dynamique au cours du temps. Nous nous proposons d’introduire une fonction objectif cherchant a` la fois a` maximiser la qualite´ de la partition (approche classique) tout en incluant un prix pour les modifica- tions de la solution au cours du temps. Une premiere` approche consiste a` payer pour chaque sommet changeant de composante, une autre consiste a` etudier´ differentes´ mesures d’entropie du changement. Si l’approche par programmation lineaire´ semble bien adaptee´ pour le premier cas, la programmation convexe pourrait etreˆ necessaire´ dans le second. Le probleme` de la decomposition´ en clusters est mo- tive´ par celui du dessin des graphes dynamiques, un veritable´ enjeu pour la comprehension´ des donnees´ collectees´ actuellement que nous souhaitons aborder a` terme. Ces travaux seront finances´ par l’ANR RDAM qui vient d’etreˆ acceptee.´

92 CHAPITRE 4. PROJET SCIENTIFIQUE : ALGORITHMES DISTRIBUES´ ET GRAPHES

4.1.3 Algorithmique de graphes

Les grands theor´ emes` de decomposition´ des graphes (par exemple ceux lies´ a` la theorie´ des graphes parfaits) utilisent des notions comme les decompositions´ en 2-join, ou de paire homogene` (gen´ eralisation´ de la decomposition´ modulaire), et enfin de skew-partition. On sait encore peu de chose sur l’algorithmique liee´ a` ces decompositions´ et nous en avons commence´ l’etude´ (these` Antoine Mamcarz). L’objectif est de construire une theorie´ des parcours de graphes. Nous avons prolonge´ l’etude´ demarr´ ee´ par D. Corneil (Toronto) qui a obtenu de nouvelles caracterisations´ des parcours classiques de graphes. Nos premiers resultats´ mettent en evidence´ les propriet´ es´ gloutonnes d’un parcours recemment´ decouvert´ (le parcours lexicographique en profondeur). Nous esperons´ mieux comprendre ces phenom´ enes` et formaliser les idees´ d’algorithmes multi-parcours (these` Jer´ emie´ Dusart). Nous travaillons egalement´ sur les calculs du diametre` et des centres de tres` grands graphes en proposant des algorithmes capables de donner un resultat´ exact memeˆ sur des tres` grands graphes. Nous envisageons de nous attaquer au probleme` de l’approximation du flot maximum dans un graphe. En effet les algorithmes exacts polynomiaux disponibles sont trop lourds pour etreˆ utilises´ sur de tres` grands graphes. Pour ce faire nous baserons notre approche sur des parcours de graphes successifs et la comparerons avec celles issues de la theorie´ spectrale des graphes (nombreuses collaboration sur ce theme` avec D. Corneil (Toronto), P. Crescenzi (Florence), R. Grossi (Pise), et l’equipe´ projet Mascotte (Sophia)). Enfin nous continuerons notre collaboration avec une equipe´ des biologistes de Paris 6 (E. Bapteste, P. Lopez) sur des algorithmes de graphes pour l’etude´ de l’evolution´ des genomes´ de virus. A ce jour nous avons propose´ une heuristique de partionnement de graphes dont nous allons publier les resultats´ en biologie.

4.1.4 Bioinformatique

Ces cinq dernieres` annees,´ de nouvelles techniques de sequençage´ dites “haut debit”´ sont apparues avec de nouveaux defis´ en terme d’assemblage et de recherche de motifs. Differents´ types de sequenceurs´ existent, les principaux etant´ le 454, le Solexa et le Solid. Ils ont en commun de gen´ erer´ d’enormes´ quantites´ de donnees´ qu’il faut rechercher dans des banques de donnees´ (typiquement GeneBank), map- per sur un genome´ (i.e. localiser les occurrences de chaque sequence´ avec erreurs dans un genome´ (de 1Mo a` 10Go), ou encore les comparer entre elles. Pour donner un exemple, un “run” de 454 gen´ ere` en 24h un million de sequences´ de 500 a` 600 bases, un “run” de Solexa gen´ ere` 50 Go de donnees´ en 3 jours. Cette volumetrie´ est appelee´ a` augmenter de maniere` exponentielle au cours des prochaines annees.´ En outre, les recherches de motifs a` effectuer devraient resister´ a` un taux de similarite´ faible, de l’ordre de 80%, ce qui est loin d’etreˆ le cas actuellement. Le Genoscope´ possede` plusieurs sorte de sequenceurs´ et participe au projet TARA d’etude´ du plancton marin. Ce projet doit mener au sequençage´ de 2000 echantillons´ d’ensembles de protistes (petits euca- ryotes unicellulaires) sur trois ans, chaque echantillon´ etant´ sequenc´ e´ par un “run” d’un des sequenceurs´ (ou parfois de plusieurs). La quantite´ de donnees´ a` manipuler est donc faramineuse. Relever ce defi´ necessite´ l’association de techniques fines en algorithmique mais aussi des techniques de parallelisme´ SIMD sur processeurs classiques (avec du code SSE par exemple) ou GPU (Graphic Processing Unit), dont l’apport exact doit etreˆ evalu´ e.´ C’est sur ce defi´ que porte le projet Mappi en collaboration des membres du Genoscope (Evry) qui s’occupent du projet TARA, de l’equipe´ d’H. Touzet du LIFL (Lille) et de l’equipe´ de D. Lavenier a` l’IRISA (Rennes). Ce projet commence´ en 2011 a porte´ ses premiers fruits, a` la fois sur des problemes` de metag´ eno-´ mique a` Rennes, sur des problemes` de recherche de bases d’ARN a` Lille et sur des recherches en indexation compacte et en recherche d’expressions reguli´ eres` particulieres` approchees´ au LIAFA (these`

93 CHAPITRE 4. PROJET SCIENTIFIQUE : ALGORITHMES DISTRIBUES´ ET GRAPHES

D. Belazzougui). 4.2 Mise en œuvre du projet

Comme on l’a vu au long de la section prec´ edente,´ on a mis en place les moyens humains et financiers pour atteindre nos objectifs scientifiques. On compte sur les forces de l’equipe´ mais tirant parti de notre reseau´ de collaborations, on a pris soin de s’associer au travers d’ANR et d’autres projets (projet bilateraux,´ pics, peps....) a` d’autres equipes´ et personnalites´ tant françaises qu’etrang´ eres` et d’inclure dans les ANR des moyens humains en doctorants et post doctorants. Au cours de l’avancee´ des recherches sur les themes` present´ es´ ci dessus, on pense, integrer´ d’autres doctorants et post doctorants en faisant des demandes de bourses a` l’Ecole Doctorale, a` la Fondation, a` la Ville de Paris.... D’un point de vue financier, les resultats´ des demandes faites en 2012, ne sont pas encore tous connus mais l’equipe´ dispose actuellement pour 2013 d’un budget d’environ 200 Ke (hors financement du laboratoire) ce qui lui assure un budget suffisant pour son financement. Actuellement les financements proviennent pour la plupart de l’ANR, et un effort doit etreˆ fait pour obtenir des financements europeens.´ Au cours de la periode´ du present´ rapport, des liens se sont consolides´ avec des entreprises (LinkFluence, OrangeLab, Thales...) et se sont concretis´ es´ par un brevet, deux theses` CIFRE (une soutenue en 2010 et une en cours), des publications communes, la participation a` la creation´ de la startup Move&Play... Par les developpements´ techniques et sociaux actuels et le domaine d’expertise de l’equipe,´ on est dans un contexte particulierement` favorable au developpement´ de collaborations avec des entreprises. Les projets de recherche sur les grands reseaux´ present´ es´ section 4.1.2 en seront le coeur. Ils devraient conduire a` la perennisation´ de theses` CIFRE au sein de notre equipe,´ a` des implications plus ou moins importantes dans des startups, a` des partenariats pour des brevets, des developpements....´ Le transfert des technologies ne se fait pas seulement via les theses` et les collaborations directes de chercheurs avec les entreprises mais aussi via les etudiants´ formes.´ L’equipe´ est active tant au sein du master professionnel que du master de recherche de l’universite.´ Quatre cours dans le master recherche, en un ensemble coherent,´ forment les etudiants´ aux recherches de l’equipe.´ Dans le master professionnel, les thematiques´ de l’equipe´ sont centrales au parcours SRI (environ 50 etudiants´ par an) et le seront encore plus dans l’evolution´ de celui-ci dans le prochain quinquennal en un parcours IMPAIRS (l’Information et la Mobilite´ : leurs Programmations, leurs Algorithmes pour l’Internet, la Repartition´ et les Systemes).`

94 Chapitre 5

Liste des publications : Algorithmes Distribues´ et Graphes

ACL : Articles dans des revues internationales ou nationales

Les publications [EFKR10; EFKR11] sont communes avec l’equipe´ ”Algorithmes et complexite”.´ [CJKPT08] avec l’equipe´ ”Automates et applications”.

[ADGFT08] Marcos Kawazoe Aguilera, Carole Delporte-Gallet, Hugues Fauconnier, Sam Toueg. “On implementing omega in systems with weak reliability and synchrony assumptions.” Distributed Computing 21.4 (2008), pp. 285–314. [BBGGJS11] Eric´ Bertin, Guillaume Beslon, Olivier Gandrillon, Sebastian´ Grauwin, Pablo Jensen, Nicolas Schabanel. “Les complexites´ : point de vue d’un institut des systemes` complexes”. Hermes` 60 (2011), pp. 145–150. [BBPV11] Djamal Belazzougui, Paolo Boldi, Rasmus Pagh, Sebastiano Vigna. “Theory and practice of monotone minimal perfect hashing.” ACM Journal of Experimental Algorithmics 16 (2011). [BCCGK09] Olivier Bournez, Philippe Chassaing, Johanne Cohen, Lucas Gerin, Xavier Koegler. “On the convergence of population protocols when population goes to infinity.” Applied Ma- thematics and Computation 215.4 (2009), pp. 1340–1350. [BCF11] Herve´ Baumann, Pierluigi Crescenzi, Pierre Fraigniaud. “Parsimonious flooding in dynamic graphs.” Distributed Computing 24.1 (2011), pp. 31–44. [BCHP08] Anna Bretscher, Derek G. Corneil, Michel Habib, Christophe Paul. “A Simple Linear Time LexBFS Cograph Recognition Algorithm.” SIAM J. Discrete Math. 22.4 (2008), pp. 1277– 1296. [BCMR08] Anne Bergeron, Cedric Chauve, Fabien Montgolfier, Mathieu Raffinot. “Computing Com- mon Intervals of K Permutations, with Applications to Modular Decomposition of Graphs.” SIAM J. Discrete Math. 22.3 (2008), pp. 1022–1039. [BCPP09] Jean-Samuel Beuscart, Dominique Cardon, Nicolas Pissard, Christophe Prieur. “Pourquoi partager mes photos de vacances avec des inconnus? Les usages de Flickr”. Reseaux´ 154 (2009). [BFFS07] Lali Barriere,` Paola Flocchini, Pierre Fraigniaud, Nicola Santoro. “Rendezvous and Elec- tion of Mobile Agents: Impact of Sense of Direction.” Theory Comput. Syst. 40.2 (2007), pp. 143–162. [BFNV08]L elia´ Blin, Pierre Fraigniaud, Nicolas Nisse, Sandrine Vial. “Distributed chasing of network intruders.” Theor. Comput. Sci. 399.1-2 (2008), pp. 12–37. [BH12] Yacine Boufkhad, Thomas Hugel. “Estimating satisfiability.” Discrete Applied Mathema- tics 160.1-2 (2012), pp. 61–80.

95 CHAPITRE 5. LISTE DES PUBLICATIONS : ALGORITHMES DISTRIBUES´ ET GRAPHES

[BJHT11] Jørgen Bang-Jensen, Fred´ eric´ Havet, Nicolas Trotignon. “Finding an induced subdivision of a digraph”. Electronic Notes in Discrete Mathematics 37 (2011), pp. 9–14. [BLMBSKCMMNST11] Robert Birke, Emilio Leonardi, Marco Mellia, Arpad Bakay, Tivadar Szeme- thy, Csaba Kiraly,` Renato Lo Cigno, Fabien Mathieu, Luca Muscariello, Saverio Niccolini, Jan Seedorf, Giuseppe Tropea. “Architecture of a network-aware P2P-TV application: the NAPA-WINE approach.” IEEE Communications Magazine 49.6 (2011), pp. 154–163. [BLS10] Stephane´ Bessy, Nicolas Lichiardopol, Jean-Sebastien´ Sereni. “Two proofs of the Bermond-Thomassen conjecture for tournaments with bounded minimum in-degree.” Dis- crete Mathematics 310.3 (2010), pp. 557–560. [BXH09] Binh-Minh Bui-Xuan, Michel Habib. “Unifying the representation of symmetric cros- sing families and weakly partitive families.” Electronic Notes in Discrete Mathematics 34 (2009), pp. 329–333. [BXHLM09] Binh-Minh Bui-Xuan, Michel Habib, Vincent Limouzy, Fabien Montgolfier. “Algorith- mic aspects of a general modular decomposition theory.” Discrete Applied Mathematics 157.9 (2009), pp. 1993–2009. [BXHP08] Binh-Minh Bui-Xuan, Michel Habib, Christophe Paul. “Competitive graph searches.” Theor. Comput. Sci. 393.1-3 (2008), pp. 72–80. [BXHR12] Binh-Minh Bui-Xuan, Michel Habib, Michael¨ Rao. “Tree-representation of set families and applications to combinatorial decompositions.” Eur. J. Comb. 33.5 (2012), pp. 688– 711. [CDEHV08b] Victor Chepoi, Feodor F. Dragan, Bertrand Estellon, Michel Habib, Yann Vaxes.` “Notes on diameters, centers, and approximating trees of delta-hyperbolic geodesic spaces and graphs.” Electronic Notes in Discrete Mathematics 31 (2008), pp. 231–234. [CDEHVX12] Victor Chepoi, Feodor F. Dragan, Bertrand Estellon, Michel Habib, Yann Vaxes,` Yang Xiang. “Additive Spanners and Distance and Routing Labeling Schemes for Hyperbolic Graphs.” Algorithmica 62.3-4 (2012), pp. 713–732. [CFIKP08] Reuven Cohen, Pierre Fraigniaud, David Ilcinkas, Amos Korman, David Peleg. “Label- guided graph exploration by a finite automaton.” ACM Transactions on Algorithms 4.4 (2008). [CFIKP09] Reuven Cohen, Pierre Fraigniaud, David Ilcinkas, Amos Korman, David Peleg. “Labeling Schemes for Tree Representation.” Algorithmica 53.1 (2009), pp. 1–15. [CHLMRR08] Pierre Charbit, Michel Habib, Vincent Limouzy, Fabien Montgolfier, Mathieu Raffinot, Michael¨ Rao. “A note on computing set overlap classes.” Inf. Process. Lett. 108.4 (2008), pp. 186–191. [CHLRR12] Derek G. Corneil, Michel Habib, Jean-Marc Lanlignel, Bruce A. Reed, Udi Rotics. “Polynomial-time recognition of clique-width ≤ 3 graphs.” Discrete Applied Mathema- tics 160.6 (2012), pp. 834–865. [CHS09] Ricardo Correa,ˆ Fred´ eric´ Havet, Jean-Sebastien´ Sereni. “About a Brooks-type theorem for improper colouring”. Australas. J. Combin. 43 (2009), pp. 219–230. [CJKPT08] Pierre Charbit, Emmanuel Jeandel, Pascal Koiran, Sylvain Perifel, Stephan´ Thomasse.´ “Finding a vector orthogonal to roughly half a collection of vectors.” J. Complexity 24.1 (2008), pp. 39–53. [CMR08] Pierre Charbit, Fabien Montgolfier, Mathieu Raffinot. “A Simple Linear Time Split De- composition Algorithm of Undirected Graphs.” SIAM J. Discrete Math. to appear (2008).

96 CHAPITRE 5. LISTE DES PUBLICATIONS : ALGORITHMES DISTRIBUES´ ET GRAPHES

[CMR11] Julien Clement,´ Stephane´ Messika, Brigitte Rozoy. “Observer des algorithmes autostabi- lisants. Vers une evaluation´ du cout”.ˆ Technique et Science Informatiques 30.1 (2011), pp. 35–57. [CMR12] Pierre Charbit, Fabien Montgolfier, Mathieu Raffinot. “Linear Time Split Decomposition Revisited”. SIAM Journal on Discrete Mathematics 26.2 (2012), pp. 499–514. DOI: 10.1 137/10080052X. URL: http://link.aip.org/link/?SJD/26/499/1. [CS07] Pierre Charbit, Alex D. Scott. “Infinite Locally Random Graphs.” Internet Mathematics 3.3 (2007), pp. 321–331. [CS08] Pierre Charbit, Andras` Sebo.¨ “Cyclic orders: Equivalence and duality.” Combinatorica 28.2 (2008), pp. 131–143. [CS11a] Pierre Charbit, Jean-Sebastien´ Sereni. “The fractional chromatic number of Zykov products of graphs.” Appl. Math. Lett. 24.4 (2011), pp. 432–437. [CS11b] David Coudert, Jean-Sebastien´ Sereni. “Characterization of graphs and digraphs with small process numbers.” Discrete Applied Mathematics 159.11 (2011), pp. 1094–1109. [CT07] Pierre Charbit, Stephan´ Thomasse.´ “Graphs with Large Girth Not Embeddable in the Sphere.” Combinatorics, Probability & Computing 16.6 (2007), pp. 829–832. [CTY07] Pierre Charbit, Stephan´ Thomasse,´ Anders Yeo. “The Minimum Feedback Arc Set Pro- blem is NP-Hard for Tournaments.” Combinatorics, Probability & Computing 16.1 (2007), pp. 1–4. [DGDF10b] Carole Delporte-Gallet, Stephane´ Devismes, Hugues Fauconnier. “Stabilizing leader election in partial synchronous systems with crash failures.” J. Parallel Distrib. Comput. 70.1 (2010), pp. 45–58. [DGF11] Carole Delporte-Gallet, Hugues Fauconnier. “Objets partages´ et detecteurs´ de defaillances.”´ Technique et Science Informatiques 30.7 (2011), pp. 841–871. [DGFG10] Carole Delporte-Gallet, Hugues Fauconnier, Rachid Guerraoui. “Tight failure detection bounds on atomic object implementations.” J. ACM 57.4 (2010). [DGFGP07] Carole Delporte-Gallet, Hugues Fauconnier, Rachid Guerraoui, Bastian Pochon. “The perfectly synchronized round-based model of distributed computing.” Inf. Comput. 205.5 (2007), pp. 783–815. [DGFGT11] Carole Delporte-Gallet, Hugues Fauconnier, Rachid Guerraoui, Andreas Tielmann. “The disagreement power of an adversary.” Distributed Computing 24.3-4 (2011), pp. 137–147. [DGFT11] Carole Delporte-Gallet, Hugues Fauconnier, Sam Toueg. “The minimum information about failures for solving non-local tasks in message-passing systems.” Distributed Com- puting 24.5 (2011), pp. 255–269. [DGHS07] Maria Patricia Dobson, Marisa Gutierrez, Michel Habib, Jayme Luiz Szwarcfiter. “On transitive orientations with restricted covering graphs.” Inf. Process. Lett. 101.3 (2007), pp. 119–125. [DH11] Arnaud Durand, Michel Habib. “Complexity issues for the sandwich homogeneous set problem.” Discrete Applied Mathematics 159.7 (2011), pp. 574–580. [DKKS10] Zdenek Dvorak, Tomas` Kaiser, Daniel Kral’,` Jean-Sebastien´ Sereni. “A note on antisym- metric flows in graphs.” Eur. J. Comb. 31.1 (2010), pp. 320–324. [DPT09] Nicolas Derhy, Christophe Picouleau, Nicolas Trotignon. “The Four-in-a-Tree Problem in Triangle-Free Graphs”. Graphs and Combinatorics 25.4 (2009), pp. 489–502.

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[EFKR10] Yuval Emek, Pierre Fraigniaud, Amos Korman, Adi Rosen.´ “On the additive constant of the k-server Work Function Algorithm.” Inf. Process. Lett. 110.24 (2010), pp. 1120–1123. [EFKR11] Yuval Emek, Pierre Fraigniaud, Amos Korman, Adi Rosen.´ “Online computation with advice.” Theor. Comput. Sci. 412.24 (2011), pp. 2642–2656. [EK11] Yuval Emek, Amos Korman. “New bounds for the controller problem.” Distributed Com- puting 24.3-4 (2011), pp. 177–186. [FFN09] Fedor V. Fomin, Pierre Fraigniaud, Nicolas Nisse. “Nondeterministic Graph Searching: From Pathwidth to Treewidth.” Algorithmica 53.3 (2009), pp. 358–373. [FGIP09] Pierre Fraigniaud, Cyril Gavoille, David Ilcinkas, Andrzej Pelc. “Distributed computing with advice: information sensitivity of graph coloring.” Distributed Computing 21.6 (2009), pp. 395–403. [FGKLL09] Pierre Fraigniaud, Cyril Gavoille, Adrian Kosowski, Emmanuelle Lebhar, Zvi Lotker. “Universal augmentation schemes for network navigability.” Theor. Comput. Sci. 410.21- 23 (2009), pp. 1970–1981. [FIP08a] Pierre Fraigniaud, David Ilcinkas, Andrzej Pelc. “Impact of memory size on graph exploration capability.” Discrete Applied Mathematics 156.12 (2008), pp. 2310–2319. [FIP08b] Pierre Fraigniaud, David Ilcinkas, Andrzej Pelc. “Tree exploration with advice.” Inf. Com- put. 206.11 (2008), pp. 1276–1287. [FIP10] Pierre Fraigniaud, David Ilcinkas, Andrzej Pelc. “Communication algorithms with advice.” J. Comput. Syst. Sci. 76.3-4 (2010), pp. 222–232. [FKL10] Pierre Fraigniaud, Amos Korman, Emmanuelle Lebhar. “Local MST Computation with Short Advice.” Theory Comput. Syst. 47.4 (2010), pp. 920–933. [FLL10a] Pierre Fraigniaud, Emmanuelle Lebhar, Zvi Lotker. “A Lower Bound for Network Navi- gability.” SIAM J. Discrete Math. 24.1 (2010), pp. 72–81. [FLL10b] Pierre Fraigniaud, Emmanuelle Lebhar, Zvi Lotker. “Recovering the long-range links in augmented graphs.” Theor. Comput. Sci. 411.14-15 (2010), pp. 1613–1625. [FN08] Pierre Fraigniaud, Nicolas Nisse. “Monotony properties of connected visible graph searching.” Inf. Comput. 206.12 (2008), pp. 1383–1393. [GMN10] Bruno Gaume, Fabien Mathieu, Emmanuel Navarro. “Building Real-World Complex Net- works by Wandering on Random Graphs”. Information - Interaction - Intelligence 10.1 (2010), pp. 73–91. URL: http://hal.inria.fr/hal-00668017. [HKLP07] Michel Habib, David Kelly, Emmanuelle Lebhar, Christophe Paul. “Can transitive orien- tation make sandwich problems easier?” Discrete Mathematics 307.16 (2007), pp. 2030– 2041. [HKMS09] Fred´ eric´ Havet, Ross J. Kang, Tobias Muller,¨ Jean-Sebastien´ Sereni. “Circular choosabi- lity.” Journal of Graph Theory 61.4 (2009), pp. 241–270. [HKS09] Fred´ eric´ Havet, Ross J. Kang, Jean-Sebastien´ Sereni. “Improper coloring of unit disk graphs.” Networks 54.3 (2009), pp. 150–164. [HKSS08] Jan Hladky,` Daniel Kral,` Jean-Sebastien´ Sereni, Michael Stiebitz. “List colorings with measurable sets.” Journal of Graph Theory 59.3 (2008), pp. 229–238. [HKSS10] Fred´ eric´ Havet, Daniel Kral’,` Jean-Sebastien´ Sereni, Riste Skrekovski. “Facial colorings using Hall’s Theorem.” Eur. J. Comb. 31.3 (2010), pp. 1001–1019. [HL09] Michel Habib, Vincent Limouzy. “On some simplicial elimination schemes for chordal graphs.” Electronic Notes in Discrete Mathematics 32 (2009), pp. 125–132.

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[HP10] Michel Habib, Christophe Paul. “A survey of the algorithmic aspects of modular decomposition.” Computer Science Review 4.1 (2010), pp. 41–59. [HRS12] Fred´ eric´ Havet, Bruce A. Reed, Jean-Sebastien´ Sereni. “Griggs and Yeh’s Conjecture and L(p, 1)-labelings.” SIAM J. Discrete Math. 26.1 (2012), pp. 145–168. [HS09a] Michel Habib, Juraj Stacho. “A Decomposition Theorem for Chordal Graphs and its Ap- plications.” Electronic Notes in Discrete Mathematics 34 (2009), pp. 561–565. [HS09b] Michel Habib, Juraj Stacho. “Linear Algorithms for Chordal Graphs of Bounded Directed Vertex Leafage.” Electronic Notes in Discrete Mathematics 32 (2009), pp. 99–108. [HS12] Michel Habib, Juraj Stacho. “Reduced clique graphs of chordal graphs.” Eur. J. Comb. 33.5 (2012), pp. 712–735. [HSS08] Fred´ eric´ Havet, Jean-Sebastien´ Sereni, Riste Skrekovski. “3-Facial Coloring of Plane Graphs.” SIAM J. Discrete Math. 22.1 (2008), pp. 231–247. [KK07b] Amos Korman, Shay Kutten. “Distributed veriﬁcation of minimum spanning trees.” Dis- tributed Computing 20.4 (2007), pp. 253–266. [KK09] Amos Korman, Shay Kutten. “A note on models for graph representations.” Theor. Com- put. Sci. 410.14 (2009), pp. 1401–1412. [KKMS09] Frantisekˇ Kardos,ˇ Daniel Kral’,´ Jozef Miskuf,ˇ Jean-Sebastien´ Sereni. “Fullerene graphs have exponentially many perfect matchings”. J. Math. Chem. 46.2 (2009), pp. 443–447. [KKP10] Amos Korman, Shay Kutten, David Peleg. “Proof labeling schemes.” Distributed Compu- ting 22.4 (2010), pp. 215–233. [KKS10] Frantisek Kardos, Daniel Kral’,` Jean-Sebastien´ Sereni. “The Last Fraction of a Fractional Conjecture.” SIAM J. Discrete Math. 24.2 (2010), pp. 699–707. [KKSS10] Alexandr V. Kostochka, Daniel Kral’,` Jean-Sebastien´ Sereni, Michael Stiebitz. “Graphs with bounded tree-width and large odd-girth are almost bipartite.” J. Comb. Theory, Ser. B 100.6 (2010), pp. 554–559. [KMMS09] Daniel Kral,` Edita Macajov` a,` Jan` Mazak,` Jean-Sebastien´ Sereni. “Circular edge-colorings of cubic graphs with girth six.” Electronic Notes in Discrete Mathematics 34 (2009), pp. 525–529. [KMMS10] Daniel Kral’,` Edita Macajov` a,` Jan` Mazak,` Jean-Sebastien´ Sereni. “Circular edge- colorings of cubic graphs with girth six.” J. Comb. Theory, Ser. B 100.4 (2010), pp. 351– 358. [KMPRSS09] Daniel Kral,` Edita Macajov` a,` Ondrej Pangrac,` Andre´ Raspaud, Jean-Sebastien´ Sereni, Martin Skoviera. “Projective, afﬁne, and abelian colorings of cubic graphs.” Eur. J. Comb. 30.1 (2009), pp. 53–69. [KMS08] Ross J. Kang, Tobias Muller,¨ Jean-Sebastien´ Sereni. “Improper colouring of (random) unit disk graphs.” Discrete Mathematics 308.8 (2008), pp. 1438–1454. [KMS12] Daniel Kral’,` Lukas` Mach, Jean-Sebastien´ Sereni. “A new lower bound based on Gromov’s method of selecting heavily covered points.” Discrete and Computation Geometry (2012), to appear. [Kor07c] Amos Korman. “General compact labeling schemes for dynamic trees.” Distributed Com- puting 20.3 (2007), pp. 179–193. [Kor10] Amos Korman. “Labeling schemes for vertex connectivity.” ACM Transactions on Algo- rithms 6.2 (2010).

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[KP07b] Amos Korman, David Peleg. “Labeling schemes for weighted dynamic trees.” Inf. Comput. 205.12 (2007), pp. 1721–1740. [KP08a] Amos Korman, David Peleg. “Compact separator decompositions in dynamic trees and applications to labeling schemes.” Distributed Computing 21.2 (2008), pp. 141–161. [KP08b] Amos Korman, David Peleg. “Dynamic routing schemes for graphs with low local density.” ACM Transactions on Algorithms 4.4 (2008). [KPR10] Amos Korman, David Peleg, Yoav Rodeh. “Constructing Labeling Schemes through Uni- versal Matrices.” Algorithmica 57.4 (2010), pp. 641–652. [KPSS09]ˇ Daniel Kral’,´ Ondrejˇ Pangrac,´ Jean-Sebastien´ Sereni, Riste Skrekovski.ˇ “Long cycles in fullerene graphs”. J. Math. Chem. 45.4 (2009), pp. 1021–1031. [KR08c] Roman Kolpakov, Mathieu Rafﬁnot. “New algorithms for text ﬁngerprinting.” J. Discrete Algorithms 6.2 (2008), pp. 243–255. [KSS08] Lukasz Kowalik, Jean-Sebastien´ Sereni, Riste Skrekovski. “Total-Coloring of Plane Graphs with Maximum Degree Nine.” SIAM J. Discrete Math. 22.4 (2008), pp. 1462– 1479. [KSS09] Daniel Kral,` Jean-Sebastien´ Sereni, Michael Stiebitz. “A New Lower Bound on the Num- ber of Perfect Matchings in Cubic Graphs.” SIAM J. Discrete Math. 23.3 (2009), pp. 1465– 1483. [KSS11] Ross J. Kang, Jean-Sebastien´ Sereni, Matej Stehl´ık. “Every Plane Graph of Maximum Degree 8 has an Edge-Face 9-Coloring.” SIAM J. Discrete Math. 25.2 (2011), pp. 514– 533. [LLMT07] Benjamin Lev´ eque,ˆ David Y. Lin, Fred´ eric´ Maffray, Nicolas Trotignon. “Detecting induced subgraphs”. Electronic Notes in Discrete Mathematics 29 (2007), pp. 207–211. [LLMT09] Benjamin Lev´ eque,ˆ David Y. Lin, Fred´ eric´ Maffray, Nicolas Trotignon. “Detecting induced subgraphs”. Discrete Applied Mathematics 157.17 (2009), pp. 3540–3551. [LMRT09] Benjamin Lev´ eque,ˆ Fred´ eric´ Maffray, Bruce A. Reed, Nicolas Trotignon. “Coloring Arte- mis graphs”. Theor. Comput. Sci. 410.21-23 (2009), pp. 2234–2240. [LPBSDHV08] Renaud Lambiotte, Christophe Prieur, Vincent Blondel, Zbigniew Smoreda, Cristo- bald Dekerchove, Etienne Huens, Paul Vandooren. “Geographical dispersal of mobile communication networks”. Physica A: Statistical Mechanics and its Applications 387.21 (2008), pp. 5317–5325. [LPS09] Nicolas Lichiardopol, Attila Po,` Jean-Sebastien´ Sereni. “A Step toward the Bermond– Thomassen Conjecture about Disjoint Cycles in Digraphs.” SIAM J. Discrete Math. 23.2 (2009), pp. 979–992. [LSSY10] Rong Luo, Jean-Sebastien´ Sereni, D. Christopher Stephens, Gexin Yu. “Equitable Coloring of Sparse Planar Graphs.” SIAM J. Discrete Math. 24.4 (2010), pp. 1572–1583. [LT10] W. Liu, Nicolas Trotignon. “The k-in-a-tree problem for graphs of girth at least k”. Discrete Applied Mathematics 158.15 (2010), pp. 1644–1649. [MLH08] Clemence´ Magnien, Matthieu Latapy, Michel Habib. “Fast computation of empirically tight bounds for the diameter of massive graphs.” ACM Journal of Experimental Algo- rithmics 13 (2008). [MPS08] Tobias Muller,¨ Attila Po,` Jean-Sebastien´ Sereni. “Lower bounding the boundary of a graph in terms of its maximum or minimum degree.” Discrete Mathematics 308.24 (2008), pp. 6581–6583.

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[MPS11] Tobias Muller,¨ Attila Po,` Jean-Sebastien´ Sereni. “Graphs with Four Boundary Vertices.” Electr. J. Comb. 18.1 (2011). [MS09] Tobias Muller,¨ Jean-Sebastien´ Sereni. “Identifying and Locating-Dominating Codes in (Random) Geometric Networks.” Combinatorics, Probability & Computing 18.6 (2009), pp. 925–952. [MTV08] Fred´ eric´ Maffray, Nicolas Trotignon, Kristina Vuskovic. “Algorithms for Square-3PC(., .)-Free Berge Graphs”. SIAM J. Discrete Math. 22.1 (2008), pp. 51–71. [NS08] Serguei Norine, Jean-Sebastien´ Sereni. “Graphs with full rank 3-color matrix and few 3- colorings.” J. Comb. Theory, Ser. B 98.5 (2008), pp. 1115–1116. [PL11] Pascal Pons, Matthieu Latapy. “Post-processing hierarchical community structures: Qua- lity improvements and multi-scale view.” Theor. Comput. Sci. 412.8-10 (2011), pp. 892– 900. [PSS09] Christophe Prieur, Alina Stoica, Zbigniew Smoreda. “Extraction de reseaux´ egocentr´ es´ dans un (tres` grand) reseau´ social”. Bull. de Methodologie´ Sociol 101.January (2009), pp. 5–28. [RP11] Stephane´ Raux, Christophe Prieur. “Stabilite´ globale et diversite´ locale dans la dynamique des commentaires de Flickr.” Technique et Science Informatiques 30.2 (2011), pp. 155– 180. [RST09] Damien Regnault, Nicolas Schabanel, Eric Thierry. “Progresses in the analysis of stochastic 2D cellular automata: A study of asynchronous 2D minority.” Theor. Comput. Sci. 410.47-49 (2009), pp. 4844–4855. [RST10] Damien Regnault, Nicolas Schabanel, Eric Thierry. “On the analysis of ”simple” 2D stochastic cellular automata.” Discrete Mathematics & Theoretical Computer Science 12.2 (2010), pp. 263–294. [Sch12a] Nicolas Schabanel. “Randomness + Determinism = Progresses: Why random processes could be favored by evolution”. Edition speciale´ sur la conference´ ”Chance at the heart of the cell” de Progress in Biophysics and Moleculer Biology (2012). A` paraˆıtre. [Ser08] Jean-Sebastien´ Sereni. “Randomly colouring graphs (a combinatorial view).” Computer Science Review 2.2 (2008), pp. 63–95. [SS11] Jean-Sebastien´ Sereni, Matej Stehl´ık. “Edge-face coloring of plane graphs with maximum degree nine.” Journal of Graph Theory 66.4 (2011), pp. 332–346. [Tro08a] Nicolas Trotignon. “Decomposing Berge graphs and detecting balanced skew partitions”. J. Comb. Theory, Ser. B 98.1 (2008), pp. 173–225. [TV10] Nicolas Trotignon, Kristina Vuskovic. “A structure theorem for graphs with no cycle with a unique chord and its consequences”. Journal of Graph Theory 63.1 (2010), pp. 31–67. [TV11] Nicolas Trotignon, Kristina Vuskovic. “On Roussel-Rubio-type lemmas and their consequences”. Discrete Mathematics 311.8-9 (2011), pp. 684–687.

C-INV : Conferences´ invitees´

[Fra07a] Pierre Fraigniaud. Informative Labeling Schemes. Expose´ invite´ 15th European Sympo- sium on Algorithms, ESA 2007, Eilat, Israel. 2007. [Fra10a] Pierre Fraigniaud. Informative Labeling Schemes. Expose´ invite´ 37th International Collo- quium on Automata, Languages and Programming, ICALP 2010, Bordeaux, France. 2010.

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[Fra10b] Pierre Fraigniaud. Informative Labeling Schemes. Expose´ invite´ 13th International Confe- rence on Database Theory, ICDT 2010, Lausanne, Switzerland. 2010. [Fra10c] Pierre Fraigniaud. On distributed computational complexities: are you Volvo-driving or NASCAR-obsessed? Expose´ invite´ 29th ACM Symposium on Principles of Distributed Computing, PODC 2010, Zurich, Switzerland. 2010. [Hab08a] Michel Habib. Chordal graphs and minimal separators revisited. Expose´ invite,´ Collo- quium in honor to 60th Marty Golombic’s birthday, Haifa. 2008. [Hab08b] Michel Habib. Efficient computation of diameter and suboptimal algorithms on graphs. Expose´ invite´ session pleni´ ere` commune Roadef – SMAI, Clermont-Ferrand. 2008. [Hab09a] Michel Habib. δ-hyperbolicity of graphs. Expose´ invite,´ 9th Haifa Workshop on Interdis- ciplinary Applications of Graph Theory, Combinatorics, and Algorithms. 2009. [Hab09c] Michel Habib. Diameter and center computations in networks. Conferencier´ invite´ session pleni´ ere,` Cologne Twente Workshop, Paris. 2009. [Hab11b] Michel Habib. Revisiting graph searches. Expose´ invite´ session pleni´ ere:` International Conference on Discrete Mathematics & Computer Science, DIMACOS 2011, Mohama- dia Maroc. 2011. [Hab12] Michel Habib. On the power of graph searching. Expose´ invite´ International Conference on Integration of AI and OR Techniques in Constraint Programming for Combinatorial Optimization Problems (CPAIOR 2012), Nantes. 2012. [Sch07] Nicolas Schabanel. Progresses in the Analysis of Stochastic 2D Cellular Automata: a Study of Asynchronous 2D Minority. Invited talk at Int. Workshop on foundations of Computer Science: Combinatorial Algorithms and Discrete Structures (WFOCOS). Maresias Beach Hotel, Brazi, June 2007. [Sch08a] Nicolas Schabanel. “Encuentra el infinito: Escher y la geometr´ıa imposible”. Conference´ invitee´ a` l’occasion de l’innauguration de l’attraction Encuentra el infinito au Museo interactivo Mirardo (MIM) de Santiago du Chili, Chili. Sept. 2008. [Sch08b] Nicolas Schabanel. “On stochastic cellular automata”. Conference´ invitee´ pour le 60eme` anniversaire de Philippe Flajolet a` l’Ecole´ normale superieure,´ Paris. Dec. 2008. [Sch09c] Nicolas Schabanel. Non-clairvoyant scheduling. Dagstuhl Event 09232 ”2nd Dynamo Workshop: Dynamic Communication Networks”, organise´ par Pierre Fraigniaud. Dag- stuhl, Deutcschland, June 2009. [Sch10c] Nicolas Schabanel. “Open problem: Structural lower bounds for precedence constraints in the Edmonds’ non-clairvoyant setting”. In: Proc. of Dagstuhl Seminars n◦10071. Feb. 2010, p. 2. [Sch11e] Nicolas Schabanel. Complex systems from a computer science point of view. Invited talk at Int. Conf. Dynamics of Complex systems (Disco), Valpara´ıso de Chile. Nov. 2011. [Sch11f] Nicolas Schabanel. On stochastic cellular Automata. Plenary invited talk at 17th Interna- tional Workshop on Cellular Automata and Discrete Complex Systems, Automata 2011, Santiago de Chile,Chile. Nov. 2011. [Sch11g] Nicolas Schabanel. Why evolution should make the random choice. Invited conference at the Int. Conf. Chance at the Heart of the Cell, La Doua. Nov. 2011. [Ser11] Jean-Sebastien´ Sereni. Points fortement couverts, combinatoire et algebres` de drapeaux. Conference´ pleni´ ere.` 2011.

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C-ACTI : Communications avec actes de conferences´ internationales

Les publications [EFKR09a; EFKR09b] sont communes avec l’equipe´ ”Algorithmes et complexite”,´ [CDGFS11a] avec l’equipe´ ”Modelisation´ et Verification”.´ [ABAST08] Louigi Addario-Berry, Omid Amini, Jean-Sebastien´ Sereni, Stephan´ Thomasse.´ “Guar- ding Art Galleries: The Extra Cost for Sculptures Is Linear.” In: Algorithm Theory - SWAT 2008, 11th Scandinavian Workshop on Algorithm Theory, Gothenburg, Sweden, July 2-4, 2008, Proceedings. Vol. 5124. Lecture Notes in Computer Science. Springer, 2008, pp. 41– 52. [ADGF08b] Mohssen Abboud, Carole Delporte-Gallet, Hugues Fauconnier. “Agreement and consistency without knowing the number of correct processes”. In: Conference´ Internationale sur les NOuvelles TEchnologies de la REpartition (Notere). Lyon, France, 2008. [ADGFHW07] Emmanuelle Anceaume, Carole Delporte-Gallet, Hugues Fauconnier, Michel Hurfin, Josef Widder. “Clock Synchronization in the Byzantine-Recovery Failure Model.” In: Principles of Distributed Systems, 11th International Conference, OPODIS 2007, Guade- loupe, French West Indies, December 17-20, 2007. Proceedings. Vol. 4878. Lecture Notes in Computer Science. Springer, 2007, pp. 90–104. [ADGFT09] Marcos Kawazoe Aguilera, Carole Delporte-Gallet, Hugues Fauconnier, Sam Toueg. “Partial synchrony based on set timeliness.” In: Proceedings of the 28th Annual ACM Sym- posium on Principles of Distributed Computing, PODC 2009, Calgary, Alberta, Canada, August 10-12, 2009. ACM, 2009, pp. 102–110. [AF12] Heger Arfaoui, Pierre Fraigniaud. “What can be computed without communications?” In: 19th International Colloquium on Structural Information and Communication Complexity (SIROCCO). Springer, LNCS, 2012. [BBCK10] Joffroy Beauquier, Janna Burman, Julien Clement,´ Shay Kutten. “On utilizing speed in networks of mobile agents”. In: PODC. ACM, 2010, pp. 305–314. [BBPV10] Djamal Belazzougui, Paolo Boldi, Rasmus Pagh, Sebastiano Vigna. “Fast Prefix Search in Little Space, with Applications.” In: Algorithms - ESA 2010, 18th Annual European Symposium, Liverpool, UK, September 6-8, 2010. Proceedings, Part I. Vol. 6346. Lecture Notes in Computer Science. Springer, 2010, pp. 427–438. [BBR09] Olivier Bailleux, Yacine Boufkhad, Olivier Roussel. “New Encodings of Pseudo-Boolean Constraints into CNF.” In: Theory and Applications of Satisfiability Testing - SAT 2009, 12th International Conference, SAT 2009, Swansea, UK, June 30 - July 3, 2009. Procee- dings. Vol. 5584. Lecture Notes in Computer Science. Springer, 2009, pp. 181–194. [BBV10] Djamal Belazzougui, Paolo Boldi, Sebastiano Vigna. “Dynamic Z-Fast Tries.” In: String Processing and Information Retrieval - 17th International Symposium, SPIRE 2010, Los Cabos, Mexico, October 11-13, 2010. Proceedings. Vol. 6393. Lecture Notes in Computer Science. Springer, 2010, pp. 159–172. [BCCKR11] Olivier Bournez, Jer´ emie´ Chalopin, Johanne Cohen, Xavier Koegler, Mikael¨ Rabie. “Computing with Pavlovian Populations.” In: Principles of Distributed Systems - 15th International Conference, OPODIS 2011, Toulouse, France, December 13-16, 2011. Pro- ceedings. Vol. 7109. Lecture Notes in Computer Science. Springer, 2011, pp. 409–420. [BCF09] Herve´ Baumann, Pierluigi Crescenzi, Pierre Fraigniaud. “Parsimonious flooding in dynamic graphs.” In: Proceedings of the 28th Annual ACM Symposium on Principles of Dis- tributed Computing, PODC 2009, Calgary, Alberta, Canada, August 10-12, 2009. ACM, 2009, pp. 260–269.

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[Bel10a] Djamal Belazzougui. “Succinct Dictionary Matching with No Slowdown.” In: Combina- torial Pattern Matching, 21st Annual Symposium, CPM 2010, New York, NY, USA, June 21-23, 2010. Proceedings. Vol. 6129. Lecture Notes in Computer Science. Springer, 2010, pp. 88–100. [Bel10b] Djamal Belazzougui. “Worst Case Efficient Single and Multiple String Matching in the RAM Model.” In: Combinatorial Algorithms - 21st International Workshop, IWOCA 2010, London, UK, July 26-28, 2010, Revised Selected Papers. Vol. 6460. Lecture Notes in Com- puter Science. Springer, 2010, pp. 90–102. [BF09] Herve´ Baumann, Pierre Fraigniaud. “Sub-linear Universal Spatial Gossip Protocols.” In: Structural Information and Communication Complexity, 16th International Colloquium, SIROCCO 2009, Piran, Slovenia, May 25-27, 2009, Revised Selected Papers. Vol. 5869. Lecture Notes in Computer Science. Springer, 2009, pp. 44–56. [BFHV12] Herve´ Baumann, Pierre Fraigniaud, Hovhannes A. Harutyunyan, R. Verclos. “The Worst Case Behavior of Randomized Gossip.” In: Theory and Applications of Models of Com- putation - 9th Annual Conference, TAMC 2012, Beijing, China, May 16-21, 2012. Procee- dings. Vol. 7287. Lecture Notes in Computer Science. Springer, 2012, pp. 330–345. [BH10] Yacine Boufkhad, Thomas Hugel. “Non Uniform Selection of Solutions for Upper Boun- ding the 3-SAT Threshold.” In: Theory and Applications of Satisfiability Testing - SAT 2010, 13th International Conference, SAT 2010, Edinburgh, UK, July 11-14, 2010. Pro- ceedings. Vol. 6175. Lecture Notes in Computer Science. Springer, 2010, pp. 99–112. [BM07] Toufik Bennouas, Fabien Montgolfier. “Random web crawls.” In: Proceedings of the 16th International Conference on World Wide Web, WWW 2007, Banff, Alberta, Canada, May 8-12, 2007. ACM, 2007, pp. 451–460. [BMMPV08] Yacine Boufkhad, Fabien Mathieu, Fabien Montgolfier, Diego Perino, Laurent Viennot. “Achievable catalog size in peer-to-peer video-on-demand systems.” In: Proceedings of the 7th international conference on Peer-to-peer systems, IPTPS’08, Tampa, FL, USA, February 25-26, 2008. USENIX, 2008, p. 4. [BMMPV09a] Yacine Boufkhad, Fabien Mathieu, Fabien Montgolfier, Diego Perino, Laurent Viennot. “An upload bandwidth threshold for peer-to-peer Video-on-Demand scalability.” In: 23rd IEEE International Symposium on Parallel and Distributed Processing, IPDPS 2009, Rome, Italy, May 23-29, 2009. IEEE, 2009, pp. 1–10. [BMMPV09b] Yacine Boufkhad, Fabien Mathieu, Fabien Montgolfier, Diego Perino, Laurent Viennot. “Fine Tuning of a Distributed VoD System.” In: Proceedings of the 18th International Conference on Computer Communications and Networks, IEEE ICCCN 2009, San Francisco, California, August 3-6, 2009. IEEE, 2009, pp. 1–7. [BN11a] Djamal Belazzougui, Gonzalo Navarro. “Alphabet-Independent Compressed Text In- dexing.” In: Algorithms - ESA 2011 - 19th Annual European Symposium, Saarbrucken,¨ Germany, September 5-9, 2011. Proceedings. Vol. 6942. Lecture Notes in Computer Science. Springer, 2011, pp. 748–759. [BN11b] Djamal Belazzougui, Gonzalo Navarro. “Improved Compressed Indexes for Full-Text Do- cument Retrieval.” In: String Processing and Information Retrieval, 18th International Symposium, SPIRE 2011, Pisa, Italy, October 17-21, 2011. Proceedings. Vol. 7024. Lec- ture Notes in Computer Science. Springer, 2011, pp. 386–397.

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[BR11] Djamal Belazzougui, Mathieu Raffinot. “Approximate Regular Expression Matching with Multi-strings.” In: String Processing and Information Retrieval, 18th International Sym- posium, SPIRE 2011, Pisa, Italy, October 17-21, 2011. Proceedings. Vol. 7024. Lecture Notes in Computer Science. Springer, 2011, pp. 55–66. [BRS08] Florent Becker, Eric Remila,´ Nicolas Schabanel. “Time Optimal Self-assembly for 2D and 3D Shapes: The Case of Squares and Cubes.” In: DNA Computing, 14th International Meeting on DNA Computing, DNA 14, Prague, Czech Republic, June 2-9, 2008. Revised Selected Papers. Vol. 5347. Lecture Notes in Computer Science. Springer, 2008, pp. 144– 155. [BXH08] Binh-Minh Bui-Xuan, Michel Habib. “A Representation Theorem for Union-Difference Families and Application.” In: LATIN 2008: Theoretical Informatics, 8th Latin American Symposium, Buzios,´ Brazil, April 7-11, 2008, Proceedings. Vol. 4957. Lecture Notes in Computer Science. Springer, 2008, pp. 492–503. [BXHLM07] Binh-Minh Bui-Xuan, Michel Habib, Vincent Limouzy, Fabien Montgolfier. “Unifying Two Graph Decompositions with Modular Decomposition.” In: Algorithms and Computa- tion, 18th International Symposium, ISAAC 2007, Sendai, Japan, December 17-19, 2007, Proceedings. Vol. 4835. Lecture Notes in Computer Science. Springer, 2007, pp. 52–64. [CDEHV08a] Victor Chepoi, Feodor F. Dragan, Bertrand Estellon, Michel Habib, Yann Vaxes.` “Dia- meters, centers, and approximating trees of delta-hyperbolicgeodesic spaces and graphs.” In: Proceedings of the 24th ACM Symposium on Computational Geometry, College Park, MD, USA, June 9-11, 2008. ACM, 2008, pp. 59–68. [CDGFS11a] Julien Clement,´ Carole Delporte-Gallet, Hugues Fauconnier, Mihaela Sighireanu. “Gui- delines for the Verification of Population Protocols.” In: 2011 International Conference on Distributed Computing Systems, ICDCS 2011, Minneapolis, Minnesota, USA, June 20-24, 2011. IEEE Computer Society, 2011, pp. 215–224. [CDTFP07] Dominique Cardon, Hel´ ene` Delaunay-Teterel,´ Cedric´ Fluckiger, Christophe Prieur. “So- ciological typology of personal blogs”. In: Proceedings of the Second International Confe- rence on Weblogs and Social Media, ICWSM 2007. The AAAI Press, 2007, pp. 2–3. [CFL08a] Augustin Chaintreau, Pierre Fraigniaud, Emmanuelle Lebhar. “Networks Become Navi- gable as Nodes Move and Forget.” In: Automata, Languages and Programming, 35th In- ternational Colloquium, ICALP 2008, Reykjavik, Iceland, July 7-11, 2008, Proceedings, Part I: Tack A: Algorithms, Automata, Complexity, and Games. Vol. 5125. Lecture Notes in Computer Science. Springer, 2008, pp. 133–144. [CFL08b] Augustin Chaintreau, Pierre Fraigniaud, Emmanuelle Lebhar. “Opportunistic Spatial Gos- sip over Mobile Social Networks”. In: 1st ACM Workshop on Online Social Networks (WOSN). 2008. [CHKMNT12] Yannick Carlinet, The Dang Huynh, Bruno Kauffmann, Fabien Mathieu, Ludovic Noi- rie, Sebastien´ Tixeuil. “Four Months in DailyMotion: Dissecting User Video Requests”. In: TRAC 2012 - 3rd International Workshop on TRaffic Analysis and Classification. Limassol, Cyprus, Aug. 2012. URL: http://hal.inria.fr/hal-00692095. [CHMNS09] David Coudert, Florian. Huc, Dorian Mazauric, Nicolas Nisse, Jean-Sebastien.´ Sereni. “Reconfiguration of the routing in WDM networks with two classes of services”. In: Pro- ceedings of the 13th international conference on Optical Network Design and Modeling. ONDM’09. Piscataway, NJ, USA: IEEE Press, 2009, pp. 146–151.

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[DGDF07] Carole Delporte-Gallet, Stephane´ Devismes, Hugues Fauconnier. “Robust Stabilizing Lea- der Election.” In: Stabilization, Safety, and Security of Distributed Systems, 9th Internatio- nal Symposium, SSS 2007, Paris, France, November 14-16, 2007, Proceedings. Vol. 4838. Lecture Notes in Computer Science. Springer, 2007, pp. 219–233. [DGDF10a] Carole Delporte-Gallet, Stephane´ Devismes, Hugues Fauconnier. “Approximation of - Timeliness.” In: Stabilization, Safety, and Security of Distributed Systems - 12th Inter- national Symposium, SSS 2010, New York, NY, USA, September 20-22, 2010. Proceedings. Vol. 6366. Lecture Notes in Computer Science. Springer, 2010, pp. 435–451. [DGDFL10] Carole Delporte-Gallet, Stephane´ Devismes, Hugues Fauconnier, Mikel Larrea. “Algo- rithms for Extracting Timeliness Graphs.” In: Structural Information and Communica- tion Complexity, 17th International Colloquium, SIROCCO 2010, Sirince, Turkey, June 7-11, 2010. Proceedings. Vol. 6058. Lecture Notes in Computer Science. Springer, 2010, pp. 127–141. [DGDFPT08] Carole Delporte-Gallet, Stephane´ Devismes, Hugues Fauconnier, Franck Petit, Sam Toueg. “With Finite Memory Consensus Is Easier Than Reliable Broadcast.” In: Principles of Distributed Systems, 12th International Conference, OPODIS 2008, Luxor, Egypt, De- cember 15-18, 2008. Proceedings. Vol. 5401. Lecture Notes in Computer Science. Sprin- ger, 2008, pp. 41–57. [DGF09] Carole Delporte-Gallet, Hugues Fauconnier. “Two Consensus Algorithms with Atomic Registers and Failure Detector Omega.” In: Distributed Computing and Networking, 10th International Conference, ICDCN 2009, Hyderabad, India, January 3-6, 2009. Procee- dings. Vol. 5408. Lecture Notes in Computer Science. Springer, 2009, pp. 251–262. [DGFFPT07] Carole Delporte-Gallet, Hugues Fauconnier, Felix C. Freiling, Lucia Draque Penso, Andreas Tielmann. “From Crash-Stop to Permanent Omission: Automatic Transformation and Weakest Failure Detectors.” In: Distributed Computing, 21st International Symposium, DISC 2007, Lemesos, Cyprus, September 24-26, 2007, Proceedings. Vol. 4731. Lecture Notes in Computer Science. Springer, 2007, pp. 165–178. [DGFG08] Carole Delporte-Gallet, Hugues Fauconnier, Rachid Guerraoui. “Sharing is harder than agreeing.” In: Proceedings of the Twenty-Seventh Annual ACM Symposium on Principles of Distributed Computing, PODC 2008, Toronto, Canada, August 18-21, 2008. ACM, 2008, pp. 85–94. [DGFGK10] Carole Delporte-Gallet, Hugues Fauconnier, Rachid Guerraoui, Anne-Marie Kermarrec. “Brief announcement: byzantine agreement with homonyms.” In: SPAA 2010: Procee- dings of the 22nd Annual ACM Symposium on Parallelism in Algorithms and Architectures, Thira, Santorini, Greece, June 13-15, 2010. ACM, 2010, pp. 74–75. [DGFGK11] Carole Delporte-Gallet, Hugues Fauconnier, Eli Gafni, Petr Kuznetsov. “Brief Announ- cement: On the Meaning of Solving a Task with a Failure Detector.” In: Distributed Com- puting - 25th International Symposium, DISC 2011, Rome, Italy, September 20-22, 2011. Proceedings. Vol. 6950. Lecture Notes in Computer Science. Springer, 2011, pp. 145–146. [DGFGK12] Carole Delporte-Gallet, Hugues Fauconnier, Eli Gafni, Petr Kuznetsov. “Wait-Freedom with Advice.” In: Proceedings of the Thirty First Annual ACM Symposium on Principles of Distributed Computing, PODC 2012, Madeira, Portugal, July 16-18, 2012. ACM, 2012. [DGFGKRTT11] Carole Delporte-Gallet, Hugues Fauconnier, Rachid Guerraoui, Anne-Marie Ker- marrec, Eric Ruppert, Hung Tran-The. “Byzantine agreement with homonyms.” In: Pro- ceedings of the 30th Annual ACM Symposium on Principles of Distributed Computing, PODC 2011, San Jose, CA, USA, June 6-8, 2011. ACM, 2011, pp. 21–30.

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[DGFGR07] Carole Delporte-Gallet, Hugues Fauconnier, Rachid Guerraoui, Eric Ruppert. “Secretive Birds: Privacy in Population Protocols.” In: Principles of Distributed Systems, 11th In- ternational Conference, OPODIS 2007, Guadeloupe, French West Indies, December 17- 20, 2007. Proceedings. Vol. 4878. Lecture Notes in Computer Science. Springer, 2007, pp. 329–342. [DGFGT08] Carole Delporte-Gallet, Hugues Fauconnier, Rachid Guerraoui, Andreas Tielmann. “The Weakest Failure Detector for Message Passing Set-Agreement.” In: Distributed Com- puting, 22nd International Symposium, DISC 2008, Arcachon, France, September 22- 24, 2008. Proceedings. Vol. 5218. Lecture Notes in Computer Science. Springer, 2008, pp. 109–120. [DGFGT09a] Carole Delporte-Gallet, Hugues Fauconnier, Rachid Guerraoui, Andreas Tielmann. “The Disagreement Power of an Adversary.” In: Distributed Computing, 23rd Internatio- nal Symposium, DISC 2009, Elche, Spain, September 23-25, 2009. Proceedings. Vol. 5805. Lecture Notes in Computer Science. Springer, 2009, pp. 8–21. [DGFGT09b] Carole Delporte-Gallet, Hugues Fauconnier, Rachid Guerraoui, Andreas Tielmann. “The disagreement power of an adversary: extended abstract.” In: Proceedings of the 28th Annual ACM Symposium on Principles of Distributed Computing, PODC 2009, Calgary, Alberta, Canada, August 10-12, 2009. ACM, 2009, pp. 288–289. [DGFT09a] Carole Delporte-Gallet, Hugues Fauconnier, Andreas Tielmann. “Fault-Tolerant Consen- sus in Unknown and Anonymous Networks.” In: 29th IEEE International Conference on Distributed Computing Systems (ICDCS 2009), 22-26 June 2009, Montreal, Quebec,´ Ca- nada. IEEE Computer Society, 2009, pp. 368–375. [DGFT09b] Carole Delporte-Gallet, Hugues Fauconnier, Sam Toueg. “Brief Announcement: The Mi- nimum Failure Detector for Non-Local Tasks in Message-Passing Systems.” In: Distri- buted Computing, 23rd International Symposium, DISC 2009, Elche, Spain, September 23-25, 2009. Proceedings. Vol. 5805. Lecture Notes in Computer Science. Springer, 2009, pp. 358–359. [DGFT09c] Carole Delporte-Gallet, Hugues Fauconnier, Sam Toueg. “The Minimum Information about Failures for Solving Non-local Tasks in Message-Passing Systems.” In: Principles of Distributed Systems, 13th International Conference, OPODIS 2009, Nˆımes, France, De- cember 15-18, 2009. Proceedings. Vol. 5923. Lecture Notes in Computer Science. Sprin- ger, 2009, pp. 115–128. [DGFTFK09] Carole Delporte-Gallet, Hugues Fauconnier, Andreas Tielmann, Felix C. Freiling, Ma- hir Kilic. “Message-efﬁcient omission-tolerant consensus with limited synchrony.” In: 23rd IEEE International Symposium on Parallel and Distributed Processing, IPDPS 2009, Rome, Italy, May 23-29, 2009. IEEE, 2009, pp. 1–8. [DGFTT12a] Carole Delporte-Gallet, Hugues Fauconnier, Hung Tran-The. “Byzantine Agreement with Homonyms in Synchronous Systems.” In: Distributed Computing and Networking - 13th International Conference, ICDCN 2012, Hong Kong, China, January 3-6, 2012. Proceedings. Vol. 7129. Lecture Notes in Computer Science. Springer, 2012, pp. 76–90. [DGFTT12b] Carole Delporte-Gallet, Hugues Fauconnier, Hung Tran-The. “Homonyms with for- geable identiﬁers”. In: 19th International Colloquium on Structural Information and Com- munication Complexity (SIROCCO). Springer, LNCS, 2012. [DGPV08] Bilel Derbel, Cyril Gavoille, David Peleg, Laurent Viennot. “On the locality of distributed sparse spanner construction.” In: Proceedings of the Twenty-Seventh Annual ACM Sym- posium on Principles of Distributed Computing, PODC 2008, Toronto, Canada, August 18-21, 2008. ACM, 2008, pp. 273–282.

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[DGPV09] Bilel Derbel, Cyril Gavoille, David Peleg, Laurent Viennot. “Local Computation of Nearly Additive Spanners.” In: Distributed Computing, 23rd International Symposium, DISC 2009, Elche, Spain, September 23-25, 2009. Proceedings. Vol. 5805. Lecture Notes in Computer Science. Springer, 2009, pp. 176–190. [EFKKP12] Yuval Emek, Pierre Fraigniaud, Amos Korman, Shay Kutten, David Peleg. “Notions of Connectivity in Overlay Networks”. In: 19th International Colloquium on Structural In- formation and Communication Complexity (SIROCCO). Springer, LNCS, 2012. [EFKR09a] Yuval Emek, Pierre Fraigniaud, Amos Korman, Adi Rosen.´ “On the Additive Constant of the k-Server Work Function Algorithm.” In: Approximation and Online Algorithms, 7th International Workshop, WAOA 2009, Copenhagen, Denmark, September 10-11, 2009. Revised Papers. Vol. 5893. Lecture Notes in Computer Science. Springer, 2009, pp. 128– 134. [EFKR09b] Yuval Emek, Pierre Fraigniaud, Amos Korman, Adi Rosen.´ “Online Computation with Advice.” In: Automata, Languages and Programming, 36th International Colloquium, ICALP 2009, Rhodes, Greece, July 5-12, 2009, Proceedings, Part I. Vol. 5555. Lecture Notes in Computer Science. Springer, 2009, pp. 427–438. [EK09a] Yuval Emek, Amos Korman. “Brief announcement: new bounds for the controller problem.” In: Proceedings of the 28th Annual ACM Symposium on Principles of Distributed Computing, PODC 2009, Calgary, Alberta, Canada, August 10-12, 2009. ACM, 2009, pp. 340–341. [EK09b] Yuval Emek, Amos Korman. “New Bounds for the Controller Problem.” In: Distributed Computing, 23rd International Symposium, DISC 2009, Elche, Spain, September 23-25, 2009. Proceedings. Vol. 5805. Lecture Notes in Computer Science. Springer, 2009, pp. 22– 34. [EK10] Yuval Emek, Amos Korman. “Efﬁcient threshold detection in a distributed environment: extended abstract.” In: Proceedings of the 29th Annual ACM Symposium on Principles of Distributed Computing, PODC 2010, Zurich, Switzerland, July 25-28, 2010. ACM, 2010, pp. 183–191. [EKS11] Yuval Emek, Amos Korman, Yuval Shavitt. “Approximating the Statistics of various Pro- perties in Randomly Weighted Graphs.” In: Proceedings of the Twenty-Second Annual ACM-SIAM Symposium on Discrete Algorithms, SODA 2011, San Francisco, California, USA, January 23-25, 2011. SIAM, 2011, pp. 1455–1467. [FG08] Pierre Fraigniaud, Cyril Gavoille. “Polylogarithmic network navigability using compact metrics with small stretch.” In: SPAA 2008: Proceedings of the 20th Annual ACM Sympo- sium on Parallelism in Algorithms and Architectures, Munich, Germany, June 14-16, 2008. ACM, 2008, pp. 62–69. [FG09] Pierre Fraigniaud, George Giakkoupis. “The effect of power-law degrees on the navigability of small worlds: [extended abstract].” In: Proceedings of the 28th Annual ACM Sym- posium on Principles of Distributed Computing, PODC 2009, Calgary, Alberta, Canada, August 10-12, 2009. ACM, 2009, pp. 240–249. [FG10a] Pierre Fraigniaud, George Giakkoupis. “On the bit communication complexity of randomized rumor spreading.” In: SPAA 2010: Proceedings of the 22nd Annual ACM Sympo- sium on Parallelism in Algorithms and Architectures, Thira, Santorini, Greece, June 13-15, 2010. ACM, 2010, pp. 134–143.

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[FG10b] Pierre Fraigniaud, George Giakkoupis. “On the searchability of small-world networks with arbitrary underlying structure.” In: Proceedings of the 42nd ACM Symposium on Theory of Computing, STOC 2010, Cambridge, Massachusetts, USA, 5-8 June 2010. ACM, 2010, pp. 389–398. [FGIP07] Pierre Fraigniaud, Cyril Gavoille, David Ilcinkas, Andrzej Pelc. “Distributed Computing with Advice: Information Sensitivity of Graph Coloring.” In: Automata, Languages and Programming, 34th International Colloquium, ICALP 2007, Wroclaw, Poland, July 9- 13, 2007, Proceedings. Vol. 4596. Lecture Notes in Computer Science. Springer, 2007, pp. 231–242. [FGKLL07] Pierre Fraigniaud, Cyril Gavoille, Adrian Kosowski, Emmanuelle Lebhar, Zvi Lotker. “Universal augmentation schemes for network navigability: overcoming the sqrt(n)- barrier.” In: SPAA 2007: Proceedings of the 19th Annual ACM Symposium on Paralle- lism in Algorithms and Architectures, San Diego, California, USA, June 9-11, 2007. ACM, 2007, pp. 1–7. [FK09] Pierre Fraigniaud, Amos Korman. “On randomized representations of graphs using short labels.” In: SPAA 2009: Proceedings of the 21st Annual ACM Symposium on Parallelism in Algorithms and Architectures, Calgary, Alberta, Canada, August 11-13, 2009. ACM, 2009, pp. 131–137. [FK10a] Pierre Fraigniaud, Amos Korman. “An optimal ancestry scheme and small universal posets.” In: Proceedings of the 42nd ACM Symposium on Theory of Computing, STOC 2010, Cambridge, Massachusetts, USA, 5-8 June 2010. ACM, 2010, pp. 611–620. [FK10b] Pierre Fraigniaud, Amos Korman. “Compact Ancestry Labeling Schemes for XML Trees.” In: Proceedings of the Twenty-First Annual ACM-SIAM Symposium on Discrete Algo- rithms, SODA 2010, Austin, Texas, USA, January 17-19, 2010. SIAM, 2010, pp. 458– 466. [FKL07] Pierre Fraigniaud, Amos Korman, Emmanuelle Lebhar. “Local MST computation with short advice.” In: SPAA 2007: Proceedings of the 19th Annual ACM Symposium on Pa- rallelism in Algorithms and Architectures, San Diego, California, USA, June 9-11, 2007. ACM, 2007, pp. 154–160. [FKLS12] Ofer Feinerman, Amos Korman, Zvi Lotker, Jean-Sebastien´ Sereni. “Collaborative Search on the Plane without Communication”. Proc. 31st Annual ACM SIGACT-SIGOPS Sympo- sium on Principles of Distributed Computing (PODC), to appear (2012). [FKP11] Pierre Fraigniaud, Amos Korman, David Peleg. “Local Distributed Decision.” In: IEEE 52nd Annual Symposium on Foundations of Computer Science, FOCS 2011, Palm Springs, CA, USA, October 22-25, 2011. IEEE, 2011, pp. 708–717. [FLL08] Pierre Fraigniaud, Emmanuelle Lebhar, Zvi Lotker. “Recovering the Long-Range Links in Augmented Graphs.” In: Structural Information and Communication Complexity, 15th International Colloquium, SIROCCO 2008, Villars-sur-Ollon, Switzerland, June 17-20, 2008, Proceedings. Vol. 5058. Lecture Notes in Computer Science. Springer, 2008, pp. 104–118. [FLV08] Pierre Fraigniaud, Emmanuelle Lebhar, Laurent Viennot. “The Inframetric Model for the Internet.” In: INFOCOM 2008. 27th IEEE International Conference on Computer Commu- nications, Joint Conference of the IEEE Computer and Communications Societies, 13-18 April 2008, Phoenix, AZ, USA. IEEE, 2008, pp. 1085–1093.

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[FP08] Pierre Fraigniaud, Andrzej Pelc. “Deterministic Rendezvous in Trees with Little Memory.” In: Distributed Computing, 22nd International Symposium, DISC 2008, Arcachon, France, September 22-24, 2008. Proceedings. Vol. 5218. Lecture Notes in Computer Science. Springer, 2008, pp. 242–256. [FP10a] Pierre Fraigniaud, Andrzej Pelc. “Delays induce an exponential memory gap for rendezvous in trees.” In: SPAA 2010: Proceedings of the 22nd Annual ACM Symposium on Paral- lelism in Algorithms and Architectures, Thira, Santorini, Greece, June 13-15, 2010. ACM, 2010, pp. 224–232. [FP10b] Pierre Fraigniaud, Hoang-Anh Phan. “Degree hunter: on the impact of balancing node degrees in de Bruijn-based overlay networks.” In: 24th IEEE International Symposium on Parallel and Distributed Processing, IPDPS 2010, Atlanta, Georgia, USA, 19-23 April 2010 - Workshop Proceedings. IEEE, 2010, pp. 1–8. [FP10c] Pierre Fraigniaud, Hoang-Anh Phan. “”Tree-Farms” for Tree-Based Multicast Schemes in Peer-to-Peer Overlay Networks.” In: Proceedings of IEEE International Conference on Communications, ICC 2010, Cape Town, South Africa, 23-27 May 2010. IEEE, 2010, pp. 1–5. [FP12] Pierre Fraigniaud, Andrzej Pelc. “Decidability Classes for Mobile Agents Computing.” In: LATIN 2012: Theoretical Informatics - 10th Latin American Symposium, Arequipa, Peru, April 16-20, 2012. Proceedings. Vol. 7256. Lecture Notes in Computer Science. Springer, 2012, pp. 362–374. [Fra07b] Pierre Fraigniaud. “Small Worlds as Navigable Augmented Networks: Model, Analysis, and Validation.” In: Algorithms - ESA 2007, 15th Annual European Symposium, Eilat, Israel, October 8-10, 2007, Proceedings. Vol. 4698. Lecture Notes in Computer Science. Springer, 2007, pp. 2–11. [FRT11] Pierre Fraigniaud, Sergio Rajsbaum, Corentin Travers. “Locality and Checkability in Wait- Free Computing.” In: Distributed Computing - 25th International Symposium, DISC 2011, Rome, Italy, September 20-22, 2011. Proceedings. Vol. 6950. Lecture Notes in Computer Science. Springer, 2011, pp. 333–347. [GGV10] Cyril Gavoille, Quentin Godfroy, Laurent Viennot. “Multipath Spanners.” In: Structural Information and Communication Complexity, 17th International Colloquium, SIROCCO 2010, Sirince, Turkey, June 7-11, 2010. Proceedings. Vol.6058. Lecture Notes in Computer Science. Springer, 2010, pp. 211–223. [GGV11] Cyril Gavoille, Quentin Godfroy, Laurent Viennot. “Node-Disjoint Multipath Spanners and Their Relationship with Fault-Tolerant Spanners.” In: Principles of Distributed Sys- tems - 15th International Conference, OPODIS 2011, Toulouse, France, December 13- 16, 2011. Proceedings. Vol. 7109. Lecture Notes in Computer Science. Springer, 2011, pp. 143–158. [GJVY07] Christophe Guettier, Philippe Jacquet, Laurent Viennot, Jacques Yelloz. “Automatic Op- timisation of Reliable Collaborative Services in OLSR Mobile Ad Hoc Networks”. In: Proceedings of IEEE MILCOM: Military Commununications Conference. Orlando, 2007, pp. 1–7. [GLMMRV07] Anh-Tuan Gai, Dmitry Lebedev, Fabien Mathieu, Fabien Montgolﬁer, Julien Reynier, Laurent Viennot. “Acyclic Preference Systems in P2P Networks.” In: Euro-Par 2007, Pa- rallel Processing, 13th International Euro-Par Conference, Rennes, France, August 28- 31, 2007, Proceedings. Vol. 4641. Lecture Notes in Computer Science. Springer, 2007, pp. 825–834.

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[GMMR07] Anh-Tuan Gai, Fabien Mathieu, Fabien Montgolfier, Julien Reynier. “Stratification in P2P Networks: Application to BitTorrent.” In: 27th IEEE International Conference on Dis- tributed Computing Systems (ICDCS 2007), June 25-29, 2007, Toronto, Ontario, Canada. IEEE Computer Society, 2007, p. 30. [GS11] George Giakkoupis, Nicolas Schabanel. “Optimal path search in small worlds: dimension matters.” In: Proceedings of the 43rd ACM Symposium on Theory of Computing, STOC 2011, San Jose, CA, USA, 6-8 June 2011. ACM, 2011, pp. 393–402. [Hab09b] Michel Habib. “Diameter and Center Computations in Networks.” In: Proceedings of the 8th Cologne-Twente Workshop on Graphs and Combinatorial Optimization, CTW 2009, Paris, France, June 2-4 2009. 2009, pp. 257–258. [HMM12] Michel Habib, Antoine Mamcarz, Fabien Montgolfier. “Algorithms for Some H-Join De- compositions.” In: LATIN 2012: Theoretical Informatics - 10th Latin American Sympo- sium, Arequipa, Peru, April 16-20, 2012. Proceedings. Vol. 7256. Lecture Notes in Com- puter Science. Springer, 2012, pp. 446–457. [HMP10] Nidhi Hegde, Fabien Mathieu, Diego Perino. “On Optimizing for Epidemic Live Strea- ming.” In: Proceedings of IEEE International Conference on Communications, ICC 2010, Cape Town, South Africa, 23-27 May 2010. IEEE, 2010, pp. 1–5. [HRS08] Fred´ eric´ Havet, Bruce A. Reed, Jean-Sebastien´ Sereni. “L(2, 1)-labelling of graphs.” In: Proceedings of the Nineteenth Annual ACM-SIAM Symposium on Discrete Algorithms, SODA 2008, San Francisco, California, USA, January 20-22, 2008. SIAM, 2008, pp. 621– 630. [HS09c] Michel Habib, Juraj Stacho. “Polynomial-Time Algorithm for the Leafage of Chordal Graphs.” In: Algorithms - ESA 2009, 17th Annual European Symposium, Copenhagen, Denmark, September 7-9, 2009. Proceedings. Vol. 5757. Lecture Notes in Computer Science. Springer, 2009, pp. 290–300. [HS11] Michel Habib, Juraj Stacho. “Unique Perfect Phylogeny Is -Hard.” In: Combinatorial Pat- tern Matching - 22nd Annual Symposium, CPM 2011, Palermo, Italy, June 27-29, 2011. Proceedings. Vol. 6661. Lecture Notes in Computer Science. Springer, 2011, pp. 132–146. [HT11] Michel Habib, Thu-Hien To. “On a Conjecture about Compatibility of Multi-states Cha- racters.” In: Algorithms in Bioinformatics - 11th International Workshop, WABI 2011, Saarbrucken,¨ Germany, September 5-7, 2011. Proceedings. Vol. 6833. Lecture Notes in Computer Science. Springer, 2011, pp. 116–127. [JV09a] Philippe Jacquet, Laurent Viennot. “Average Size of Unstretched Remote-Spanners”. In: 5th ACM Workshop on Analytic Algorithmics and Combinatorics (ANALCO). New York, 2009, pp. 23–33. [JV09b] Philippe Jacquet, Laurent Viennot. “Remote-spanners: What to know beyond neighbors.” In: 23rd IEEE International Symposium on Parallel and Distributed Processing, IPDPS 2009, Rome, Italy, May 23-29, 2009. IEEE, 2009, pp. 1–10. [KK07a] Amos Korman, Shay Kutten. “Controller and estimator for dynamic networks.” In: Pro- ceedings of the Twenty-Sixth Annual ACM Symposium on Principles of Distributed Com- puting, PODC 2007, Portland, Oregon, USA, August 12-15, 2007. ACM, 2007, pp. 175– 184. [KK07c] Amos Korman, Shay Kutten. “Labeling Schemes with Queries.” In: Structural Information and Communication Complexity, 14th International Colloquium, SIROCCO 2007, Cas- tiglioncello, Italy, June 5-8, 2007, Proceedings. Vol. 4474. Lecture Notes in Computer Science. Springer, 2007, pp. 109–123.

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[KKM11] Amos Korman, Shay Kutten, Toshimitsu Masuzawa. “Fast and compact self stabilizing verification, computation, and fault detection of an MST.” In: Proceedings of the 30th Annual ACM Symposium on Principles of Distributed Computing, PODC 2011, San Jose, CA, USA, June 6-8, 2011. ACM, 2011, pp. 311–320. [KKP11] Liah Kor, Amos Korman, David Peleg. “Tight Bounds For Distributed MST Verifica- tion.” In: 28th International Symposium on Theoretical Aspects of Computer Science, STACS 2011, March 10-12, 2011, Dortmund, Germany. Vol. 9. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2011, pp. 69–80. [Kor07d] Amos Korman. “Labeling Schemes for Vertex Connectivity.” In: Automata, Languages and Programming, 34th International Colloquium, ICALP 2007, Wroclaw, Poland, July 9-13, 2007, Proceedings. Vol. 4596. Lecture Notes in Computer Science. Springer, 2007, pp. 102–109. [Kor08] Amos Korman. “Improved compact routing schemes for dynamic trees.” In: Proceedings of the Twenty-Seventh Annual ACM Symposium on Principles of Distributed Computing, PODC 2008, Toronto, Canada, August 18-21, 2008. ACM, 2008, pp. 185–194. [Kor09] Amos Korman. “Compact Routing Schemes for Dynamic Trees in the Fixed Port Model.” In: Distributed Computing and Networking, 10th International Conference, ICDCN 2009, Hyderabad, India, January 3-6, 2009. Proceedings. Vol. 5408. Lecture Notes in Computer Science. Springer, 2009, pp. 218–229. [KP07a] Amos Korman, David Peleg. “Compact Separator Decompositions in Dynamic Trees and Applications to Labeling Schemes.” In: Distributed Computing, 21st International Sym- posium, DISC 2007, Lemesos, Cyprus, September 24-26, 2007, Proceedings. Vol. 4731. Lecture Notes in Computer Science. Springer, 2007, pp. 313–327. [KR08a] Roman Kolpakov, Mathieu Raffinot. “Approximate Regular Expression Matching with Multi-strings”. In: String Processing and Information Retrieval, 18th International Sympo- sium, SPIRE 2008, Melbourne, Australia, November 10-12, 2011. Proceedings. Ed. by A. Amir, A.Turpin, and A. Moffat. Vol. 5280. Lecture Notes in Computer Science. Springer, 2008, pp. 15–26. [KR08b] Roman Kolpakov, Mathieu Raffinot. “Faster Text Fingerprinting.” In: String Proces- sing and Information Retrieval, 15th International Symposium, SPIRE 2008, Melbourne, Australia, November 10-12, 2008. Proceedings. Vol. 5280. Lecture Notes in Computer Science. Springer, 2008, pp. 15–26. [KSV11] Amos Korman, Jean-Sebastien´ Sereni, Laurent Viennot. “Toward more localized local algorithms: removing assumptions concerning global knowledge.” In: Proceedings of the 30th Annual ACM Symposium on Principles of Distributed Computing, PODC 2011, San Jose, CA, USA, June 6-8, 2011. ACM, 2011, pp. 49–58. [LMR07] Vincent Limouzy, Fabien Montgolfier, Michael¨ Rao. “NLC-2 Graph Recognition and Iso- morphism.” In: Graph-Theoretic Concepts in Computer Science, 33rd International Work- shop, WG 2007, Dornburg, Germany, June 21-23, 2007. Revised Papers. Vol. 4769. Lec- ture Notes in Computer Science. Springer, 2007, pp. 86–98. [LS08] Emmanuelle Lebhar, Nicolas Schabanel. “Graph Augmentation via Metric Embedding.” In: Principles of Distributed Systems, 12th International Conference, OPODIS 2008, Luxor, Egypt, December 15-18, 2008. Proceedings. Vol. 5401. Lecture Notes in Computer Science. Springer, 2008, pp. 217–225.

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[Mat10b] Fabien Mathieu. “Heterogeneity in data-driven live streaming: Blessing or curse?” In: 24th IEEE International Symposium on Parallel and Distributed Processing, IPDPS 2010, At- lanta, Georgia, USA, 19-23 April 2010 - Workshop Proceedings. IEEE, 2010, pp. 1–8. [Mat11] Fabien Mathieu. “Live seeding: Performance bounds of seeders for P2P live streaming.” In: 2011 IEEE International Conference on Peer-to-Peer Computing, P2P 2011, Kyoto, Japan, August 31 - September 2, 2011. IEEE, 2011, pp. 172–181. [MFT10] Raphael Machado, Celina M. Herrera Figueiredo, Nicolas Trotignon. “Chromatic Index of Chordless Graphs”. In: CTW. Ed. by Ulrich Faigle, Rainer Schrader, and Daniel Herrmann. 2010, pp. 51–54. [MP10b] Fabien Mathieu, Diego Perino. “On resource aware algorithms in epidemic live streaming”. In: ITC 2010 - 22nd International Teletraffic Congress. Amsterdam, Netherlands: IEEE, 2010, pp. 1 –8. URL: http://hal.inria.fr/hal-00668321. [MSV11a] Fabien Montgolfier, Mauricio Soto, Laurent Viennot. “Asymptotic Modularity of Some Graph Classes.” In: Algorithms and Computation - 22nd International Symposium, ISAAC 2011, Yokohama, Japan, December 5-8, 2011. Proceedings. Vol. 7074. Lecture Notes in Computer Science. Springer, 2011, pp. 435–444. [MSV11c] Fabien Montgolfier, Mauricio Soto, Laurent Viennot. “Treewidth and Hyperbolicity of the Internet.” In: Proceedings of The Tenth IEEE International Symposium on Networking Computing and Applications, NCA 2011, August 25-27, 2011, Cambridge, Massachusetts, USA. IEEE Computer Society, 2011, pp. 25–32. [MV10] Fabien Mathieu, Laurent Viennot. “Local Aspects of the Global Ranking of Web Pages.” In: 10th International Conference on Innovative Internet Community Services (ICS), Jubi- lee Edition 2010, June 3-5, 2010, Bangkok, Thailand. Vol. 165. LNI. GI, 2010, pp. 493– 506. [PPBCP08] Christophe Prieur, Nicolas Pissard, Jean-Samuel Beuscart, Dominique Cardon, Pascal Pons. “Thematic and Social Indicators for Flickr Groups.” In: Proceedings of the Second International Conference on Weblogs and Social Media, ICWSM 2008, Seattle, Washing- ton, USA, March 30 - April 2, 2008. The AAAI Press, 2008. [PRS10] Kirk Pruhs, Julien Robert, Nicolas Schabanel. “Minimizing Maximum Flowtime of Jobs with Arbitrary Parallelizability.” In: Approximation and Online Algorithms - 8th Inter- national Workshop, WAOA 2010, Liverpool, UK, September 9-10, 2010. Revised Papers. Vol. 6534. Lecture Notes in Computer Science. Springer, 2010, pp. 237–248. [Raf11] Mathieu Raffinot. “Consecutive Ones Property Testing: Cut or Swap.” In: Models of Com- putation in Context - 7th Conference on Computability in Europe, CiE 2011, Sofia, Bulga- ria, June 27 - July 2, 2011. Proceedings. Vol. 6735. Lecture Notes in Computer Science. Springer, 2011, pp. 239–249. [RGP11] Stephane´ Raux, Nils Grunwald,¨ Christophe Prieur. “Describing the Web in less than 140 Characters.” In: Proceedings of the Fifth International Conference on Weblogs and Social Media, Barcelona, Catalonia, Spain, July 17-21, 2011. The AAAI Press, 2011. [RS08] Julien Robert, Nicolas Schabanel. “Non-clairvoyant scheduling with precedence constraints.” In: Proceedings of the Nineteenth Annual ACM-SIAM Symposium on Discrete Algorithms, SODA 2008, San Francisco, California, USA, January 20-22, 2008. SIAM, 2008, pp. 491–500.

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[RST08] Damien Regnault, Nicolas Schabanel, Eric Thierry. “On the Analysis of ”Simple” 2D Sto- chastic Cellular Automata.” In: Language and Automata Theory and Applications, Second International Conference, LATA 2008, Tarragona, Spain, March 13-19, 2008. Revised Pa- pers. Vol. 5196. Lecture Notes in Computer Science. Springer, 2008, pp. 452–463. [SCB10] Alina Stoica, Thomas Couronne, J.S. Beuscart. “To be a star is not only metaphoric: from popularity to social linkage”. In: ICWSM. 2010, pp. 154–161. [Sch11c] Nicolas Schabanel. “Analyzing Search Algorithms in Small Worlds”. In: Proc. of Interna- tional Workshop TERANET: Toward Evolutive Routing Algorithms for scale-free/internet- like NETworks (colocated with DISC 2011). Roma, Italy, Sept. 2011, 4 pages. [SHKKNPPW11] Atish Das Sarma, Stephan Holzer, Liah Kor, Amos Korman, Danupon Nanong- kai, Gopal Pandurangan, David Peleg, Roger Wattenhofer. “Distributed veriﬁcation and hardness of distributed approximation.” In: Proceedings of the 43rd ACM Symposium on Theory of Computing, STOC 2011, San Jose, CA, USA, 6-8 June 2011. ACM, 2011, pp. 363–372. [SP09a] Alina Stoica, Christophe Prieur. “Structure of Neighborhoods in a Large Social Network.” In: Proceedings IEEE CSE’09, 12th IEEE International Conference on Computational Science and Engineering, August 29-31, 2009, Vancouver, BC, Canada. IEEE Computer Society, 2009, pp. 26–33. [SP09b] Alina Stoica, Christophe Prieur. “Structure of neighborhoods in a large social network”. In: Proceedings of the 2009 IEEE International Conference on Social Computing (Social- Com). IEEE Computer Society, 2009. [TCHP08] Marc Tedder, Derek G. Corneil, Michel Habib, Christophe Paul. “Simpler Linear-Time Modular Decomposition Via Recursive Factorizing Permutations.” In: Automata, Lan- guages and Programming, 35th International Colloquium, ICALP 2008, Reykjavik, Ice- land, July 7-11, 2008, Proceedings, Part I: Tack A: Algorithms, Automata, Complexity, and Games. Vol. 5125. Lecture Notes in Computer Science. Springer, 2008, pp. 634–645. [TH09] Thu-Hien To, Michel Habib. “Level-k Phylogenetic Networks Are Constructable from a Dense Triplet Set in Polynomial Time.” In: Combinatorial Pattern Matching, 20th Annual Symposium, CPM 2009, Lille, France, June 22-24, 2009, Proceedings. Vol. 5577. Lecture Notes in Computer Science. Springer, 2009, pp. 275–288. [TLP09] Fabien Tarissan, Matthieu Latapy, Christophe Prieur. “Efﬁcient Measurement of Complex Networks Using Link Queries”. In: IEEE International Workshop on Network Science For Communication Networks (NetSciCom’09), 2009. C-ACTN : Communications avec actes de conferences´ nationales

La publication [CDGFS11b] est commune avec l’equipe´ ”Modelisation´ et Veriﬁcation”.´ [ADGF07] Mohssen Abboud, Carole Delporte-Gallet, Hugues Fauconnier. “Rseaux´ de capteurs avec detecteurs´ de collision”. In: Journees´ Doctorales en informatique et reseaux´ (CDUR). Marne la Vallee,´ France, 2007. [ADGF08a] Mohssen Abboud, Carole Delporte-Gallet, Hugues Fauconnier. “Accord sans connaˆıtre tout le monde un pas vers la dynamicite”.´ In: Journees´ Francophones sur la Coherence´ des Donnees´ en Univers Reparti´ (CDUR). Lyon, France, 2008. [CDGFS11b] Julien Clement,´ Carole Delporte-Gallet, Hugues Fauconnier, Mihaela Sighireanu. “Mode d’emploi pour la veriﬁcation´ des protocoles de population”. In: 13emes` Rencontres Francophones sur les Aspects Algorithmiques de Tel´ ecommunications´ (AlgoTel). Ed. by Pascal Ducourthial Bertrand et Felber. Cap Esterel,´ France, 2011.

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[DGDF08] Carole Delporte-Gallet, Stephane´ Desvimes, Hugues Fauconnier. “Election Robuste, Auto-Stabilisante et Efficace”. In: 10emes` Rencontres Francophones sur les Aspects Al- gorithmiques de Tel´ ecommunications´ . Saint-Malo, France, May 2008. [DGDFPT09] Carole Delporte-Gallet, Stephane´ Devismes, Hugues Fauconnier, Franck Petit, Sam Toueg. “Quand le consensus est plus simple que la diffusion fiable”. In: 11emes` Ren- contres Francophones sur les Aspects Algorithmiques de Tel´ ecommunications(AlgoTel)´ . Ed. by Augustin Chaintreau and Clemence Magnien. Carry Le Rouet, France, 2009. [DGFGKRTT12] Carole Delporte-Gallet, Hugues Fauconnier, Rachid Guerraoui, Anne-Marie Ker- marrec, Eric Ruppert, Hung Tran-The. “Byzantine Agreement with Homonyms (Accord Byzantin avec des Homonymes)”. In: 14emes` Rencontres Francophones sur les Aspects Algorithmiques de Tel´ ecommunications´ (AlgoTel). La Grande Motte, France, 2012. [DGFGT10] Carole Delporte-Gallet, Hugues Fauconnier, Rachid Guerraoui, Andreas Tielmann. “La puissance de desaccord´ d’un adversaire”. In: 12emes` Rencontres Francophones sur les As- pects Algorithmiques de Tel´ ecommunications´ (AlgoTel). Maria Gradinariu Potop-Butucaru et Herve´ Rivano. Belle Dune, France, 2010. [JV07] Philippe Jacquet, Laurent Viennot. “Bi-connexite,´ k-connexite´ et multipoints relais”. In: ALGOTEL. Oleron,´ 2007, pp. 1–4. [Mat10c] Fabien Mathieu. “P2P Live Seeding: Efficiency of Seeders in P2P Live Streaming”. In: 12emes` Rencontres Francophones sur les Aspects Algorithmiques de Tel´ ecommunications´ (AlgoTel). Ed. by Maria Gradinariu Potop-Butucaru and Herve´ Rivano. Belle Dune, France, 2010. URL: http://hal.inria.fr/inria-00477363. [MSV11b] Fabien Montgolfier, Mauricio Soto, Laurent Viennot. “Clustering de metrique´ et clustering de graphe”. In: 13es Rencontres Francophones sur les Aspects Algorithmiques des Tel´ ecommunications´ (ALGOTEL). Cap Esterel,´ 2011, pp. 1–4. [Sch09b] Nicolas Schabanel. Les systemes` complexes : reflexions´ personnelles d’un informaticien. 3eme` Colloque national du CNRS ”Vers une science et une ingen´ erie´ des systemes` complexes”. Paris, France, Nov. 2009.

C-COM : Communications orales sans actes en conferences´ internationales ou nationales

[Fra08] Pierre Fraigniaud. Tight bounds on the efficiency of greedy navigation in social small worlds. 2nd International Conference on Network Control and Optimization, NET-COOP 2008, Paris, France. 2008. [Fra10d] Pierre Fraigniaud. Tight bounds on the efficiency of greedy navigation in social small worlds. Institute of Mathematical Statistics Annual Meeting, IMS 2010, Gothenburg, Swe- den. 2010. [Fra10e] Pierre Fraigniaud. Tight bounds on the efficiency of greedy navigation in social small worlds. SIAM Conference on Discrete Mathematics, SIAM DM 2010, Austin, Texas, Etats-Unis. 2010. [Hab08c] Michel Habib. Robust algorithms on graphs. Expose´ invite´ a` l’occasion du 75 eme` anniversaire de Jack Edmonds, IHP Paris. 2008. [Hab11a] Michel Habib. Algorithms for some H-join decomposition of graphs. Expose´ invite´ GTCO 2011 - Workshop on Graph Theory and Combinatorial Optimization, Shanghai China. 2011. [Kor07a] Amis Korman. 2nd Workshop on Locality Preserving Distributed Computing Methods (LOCALITY). 2007.

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[Kor07b] Amis Korman. Seven open questions about detecting induced subgraphs. 7th Haifa Work- shop on Interdisciplinary Applications , Haifa, Israel.¨ 2007. [Sch09a] Nicolas Schabanel. Les systemes` complexes : reﬂexions´ personnelles d’un informaticien. Colloque national du CNRS (SISC 2009), Paris, France. 2009. [Sch09d] Nicolas Schabanel. Non-clairvoyant scheduling. Dagstuhl Event 09232 ”2nd Dynamo Workshop: Dynamic Communication Networks”, Dagstuhl, Deutschland. 2009. [Sch10a] Nicolas Schabanel. Escher et la spirale impossible. Conference´ (45 min) grand public dans le cadre des journees´ ”Tourbillons, spirales et labyrinthes”. Universite´ Paris Diderot, May 2010. [Sch10b] Nicolas Schabanel. Non-clairvoyant with precedence constraints: Towards a measure of the worst case degree of parallelism within a precedence constraints DAG structure. Dag- stuhl Seminar n◦10071 ”Scheduling”, Dagstuhl, Deutschland. 2010. [Sch11d] Nicolas Schabanel. Analyzing Search Algorithms in Small Worlds. International Workshop ”Toward Evolutive Routing Algorithms for scale-free/internet-like NETworks” (TERA- NET 2011, colocated with DISC 2011), Roma, Italy. 2011. [Sch12b] Nicolas Schabanel. Relations entre complexite,´ hasard et desordre´ : le regard informatique. Conference´ (45 min) grand public dans le cadre des journees´ ”Complexite/d´ esordre”.´ Uni- versite´ Paris Diderot, June 2012. [Ser10a] Jean-Sebastien´ Sereni. The last fraction of a fractional conjecture and open problems. In- vite´ au Mini-Symposium sur la coloration de graphes. 2010. [Ser10b] Jean-Sebastien´ Sereni. Tight bounds on the efﬁciency of greedy navigation in social small worlds. SIAM Conference on Discrete Mathematics, SIAM DM 2010, Austin, Texas, Etats-Unis. 2010. [Tro08b] Nicolas Trotignon. On graphs that do not contain a cycle with a unique chord. Spring Sou- theast Sectional Meeting of the AMS,Session on Structural Graph Theory, Baton-Rouge, USA. 2008. [Tro09a] Nicolas Trotignon. Berge graphs with no balanced skew partition and no homogeneous pair. Workshop on Graph Colouring and Structure, Princeton, USA. 2009. [Tro09b] Nicolas Trotignon. Even pairs in Berge graphs. 75eme` anniversaire de Jack Edmonds, Paris, France. 2009. [Tro09c] Nicolas Trotignon. The k-in-a- tree problem for graphs of girth at least k. Workshop on Graphs and Algorithms, Bertinoro, Italie. 2009. [Tro10a] Nicolas Trotignon. Excluding subdivisions of a bull. Workshop on Graph Colouring, Haifa, Israel,¨ aoutˆ 2010. 2010. [Tro10b] Nicolas Trotignon. Perfect graphs : many old things and several new things. Centenaire de Celina de Figueiredo et Fred´ eric´ Maffray, Grenoble, France, 2010. [Tro10c] Nicolas Trotignon. Seven open questions about detecting induced subgraphs. 2nd Work- shop on Graph Decompositions,Theoretical, Algorithmic and Logical Aspects, Luminy, France. 2010.

Participation sur invitation a` des rencontres scientiﬁques :

Czech-French-Slovene workshop on Graph Colouring, Puyloubier, France. Automnes/Hivers 2008, 2009 et 2010 (Jean-Sebastien´ Sereni). Workshop on Sublinear Algorithms, Bertinoro, Italy. May 22-27, 2011 (Pierre Fraigniaud).

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Research Meeting and School on Distributed Computing by Mobile Robots (MAC), Ottawa, Ca- nada. August 15-18, 2010 (Pierre Fraigniaud). 3rd Workshop on Graph Searching, Theory and Applications, Valtice, Czech Republic. October 5- 9, 2009 (Pierre Fraigniaud). 1st Workshop on New Challenges in Distributed Systems, Valpara´ıso, Chile. April 6-9, 2009 (Pierre Fraigniaud). Workshop on Lower Bounds for Distributed Computing, Banff, Canada. January 25-30, 2009 (Pierre Fraigniaud). 2nd Workshop on Graph searching, theory and applications, Praia da Redonda, Ceara, Brazil. Fe- bruary 25-28, 2008 (Pierre Fraigniaud). Dagstuhl 2009, Seminar on Non-clairvoyant scheduling, June 1-5, 2009 (Nicolas Schabanel). Dagstuhl 2010, Seminar onNon-clairvoyant with precedence constraints : Towards a measure of the worst case degree of parallelism within a precedence constraints DAG structure, February 14-19, 2010 (Nicolas Schabanel). Dagstuhl 2011, Seminar on Packing and Scheduling Algorithms for Information and Communication Services, February 27-March 3, 2011 (Nicolas Schabanel). Dagstuhl 2012, Seminar on Applications of Combinatorial Topology to Computer Science, February 18-23, 2012 (Carole Delporte, Hugues Fauconnier et Pierre Fraigniaud).

DO : Directions d’ouvrages ou de revues

[FFKT11] Fedor V. Fomin, Pierre Fraigniaud, Stephan Kreutzer, Dimitrios M. Thilikos. “Special Is- sue on ”Theory and Applications of Graph Searching Problems”.” Theor. Comput. Sci. 412.24 (2011), p. 2699. [FFT08] Fedor V. Fomin, Pierre Fraigniaud, Dimitrios M. Thilikos. “Forewords: Special issue on graph searching.” Theor. Comput. Sci. 399.3 (2008), p. 157. [Fra07c] Pierre Fraigniaud. “Special Issue DISC 2005.” Distributed Computing 20.3 (2007), p. 163. [GF11] Cyril Gavoille, Pierre Fraigniaud, eds. Proceedings of the 30th Annual ACM Symposium on Principles of Distributed Computing, PODC 2011, San Jose, CA, USA, June 6-8, 2011. ACM, 2011. [PH10] Christophe Paul, Michel Habib, eds. Graph-Theoretic Concepts in Computer Science, 35th International Workshop, WG 2009, Montpellier, France, June 24-26, 2009. Revised Papers. 2010.

OS : Ouvrages scientiﬁques

[Mat10a] Fabien Mathieu. “Acyclic Preference-Based Systems”. In: Handbook of Peer-to-Peer Net- working. Ed. by Xuemin Shen, Heather Yu, John Buford, and Mursalin Akon. Springer US, 2010, pp. 1165–1203. URL: http://hal.inria.fr/hal-00667351. [MP10a] Fabien Mathieu, Diego Perino. “Diffusion epid´ emique´ pour du contenu live”. In: Evolution des technologies pair-a-pair,` optimination, securit´ e´ et application. Ed. by Bertrand Ma- thieu and Mikaelˆ Salaun.¨ HERMES` / LAVOISIER, Oct. 2010, pp. 97–132. URL: http: //hal.inria.fr/hal-00668019. [PM10] Diego Perino, Fabien Mathieu. “Epidemic Live Streaming”. In: Streaming Media Ar- chitectures, Techniques, and Applications: Recent Advances. Ed. by Ce Zhu, Yue- nan Li, and Xiamu Niu. IGI Global, Sept. 2010, pp. 311–336. URL: http : //hal.inria.fr/hal-00668018.

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[Schut] Nicolas Schabanel. Systemes` complexes & Algorithmes. Habilitation a` diriger des recherches, Universite´ Paris Diderot. soutenue le 26 fevrier´ 2010.

PV : Publications de vulgarisation

[LS07] Emmanuelle Lebhar, Nicolas Schabanel. “Routage dans les petits mondes”. )i( interstices (2007). http://interstices.info/jcms/c 15920/routage-dans-les-petits-mondes. [SP12] Nicolas Schabanel, Pierre Pansu. “Couper, attendrir, trancher, reduire:´ un conte culinaire sur la resolution´ informatique des problemes` difficiles”. L’explosition des mathematiques´ (2012). A` paraˆıtre, 6 pages. [Vie08] Laurent Viennot. “Les reseaux´ ont la fibre de l’information”. DocSciences 5 (2008), pp. 34–39. [Vie09] Laurent Viennot. Idee´ reçue : Web et Internet, c’est la memeˆ chose. Interstices (French vulgarization site). 2009. URL: http://interstices.info/jcms/c{\_}4275 5/web-et-internet-c-est-la-meme-chose.

AP : Autres productions

[CFLP11] Dominique Cardon, Guilhem Fouetillou, Clemence´ Lerondeau, Christophe Prieur. “Es- quisse de geographie´ de la blogosphere` politique (2007-2009)”. In: continuerlalutte.com, les partis politiques sur le web. Presses de Sciences Po, 2011, pp. 1–19. [CP07] Dominique Cardon, Christophe Prieur. “Les reseaux´ de relations sur Internet : un objet de recherche pour l’informatique et les sciences sociales”. In: Humanites´ Numeriques,´ vol. 1. Ed. by Bernard Reber and Claire Brossaud. Hermes,` 2007. Chap. 8. [MP08] Fabien Mathieu, Diego Perino. Utilisation d’un ensemble de clients privilegi´ es´ pour une diffusion collaborative de contenu. Brevet N. 0851025. 2008. [NR07] G. Navarro, M. Rafﬁnot. Flexible pattern matching in strings. Cambridge University Press (traduction chinoise). Dec. 2007. [PCPBP07] Christophe Prieur, Dominique Cardon, Pascal Pons, J.S. Beuscart, N. Pissard. The strength of weak cooperation: A case study on Flickr. Tech. rep. arxiv, 2007. URL: http: //arxiv.org/pdf/0802.2317. [PS08] Christophe Prieur, Giambattista Salinari. Social distances, or What lies beneath preferen- tial attachment. Tech. rep. hal-univ-diderot.archives-ouvertes.fr, 2008, pp. 1–17. [Sch10d] Nicolas Schabanel. Preuve complete` du theor´ eme` PCP. 10h d’enregistrement video´ disponibles sur dailymotion.fr/NicolasSchabanel. June 2010. [Sch11a] Nicolas Schabanel. 12h d’enregistrement video´ du Int. Workshop ”Expanders and Deran- domization”. Disponible sur dailymotion.fr/NicolasSchabanel. Institut Henri Poincare,´ Pa- ris, France, Mar. 2011. [Sch11b] Nicolas Schabanel. 20h d’enregistrement video´ du Int. Workshop ”Metric embeddings, algorithms and hardness of approximation”. Disponible sur dailymotion.fr/NicolasSchabanel. Institut Henri Poincare,´ Paris, France, Jan. 2011. [SSP12] Alina Stoica, Zbigniew Smoreda, Christophe Prieur. “A local structure-based method for nodes clustering . Application to a large mobile phone social network”. In: Social Network Analysis and Mining. Ed. by Tansel Ozyer.¨ to appear. 2012. [Tie09] Andreas Tielmann. “A review of DISC 2009”. SIGACT News 40.4 (2009), pp. 75–79.

118 Chapitre 6

Annexes : Algorithmes Distribues´ et Graphes

6.1 Composition et vie scientiﬁque

Responsable : Carole Delporte-Gallet Anciens responsables : Michel Habib (jusqu’au 31 decembre´ 2007), Pierre Fraigniaud (du 1er janvier 2008 jusqu’au 31 decembre´ 2009)

6.1.1 Liste actuelle des membres

6.1.1.1 Membres permanents (2012)

Tous les enseignants chercheurs sont en poste a` l’universite´ Paris Diderot. Yacine Boufkhad Maˆıtre de conference´ Pierre Charbit Maˆıtre de conference´ Carole Delporte-Gallet Professeur HdR (arrivee´ oct 2007) Hugues Fauconnier Maˆıtre de conference´ HdR (arrive´ oct 2007) Pierre Fraigniaud Directeur de recherche CNRS HdR (arrive´ jan 2007) Michel Habib Professeur Doc d’Etat Amos Korman Charge´ de recherche CNRS (arrive´ sept 2007) Fabien de Montgolﬁer Maˆıtre de conference´ Christophe Prieur Maˆıtre de conference´ Mathieu Rafﬁnot Charge´ de recherche CNRS HdR (arrive´ oct 2007) Nicolas Schabanel Directeur de recherche CNRS HdR (arrive´ juil 2008) Jean-Sebastien´ Sereni Charge´ de recherche CNRS (arrive´ oct 2008) Laurent Viennot Directeur de recherche INRIA HdR

6.1.1.2 Doctorants et post-doctorants (2012)

Doctorants : Pierre Aboulker Bourse ED Heger Arfaoui Bourse ED Herve Baumann Allocation Thematique´ Jer´ emie´ Dusart Bourse ED Xavier Koegler ANM de l’ENS Antoine Mamcarz Allocation CNRS Stephane´ Raux These` CIFRE Hung Tran The Financement ANR

119 CHAPITRE 6. ANNEXES : ALGORITHMES DISTRIBUES´ ET GRAPHES

Post-doctorant et ATER : Abdelhamid Salah Brahim ATER Zelealem Yilma Post-doctorant

6.1.1.3 Autres (2012)

Fabien Mathieu Chercheur INRIA contrat de dec´ 2010 a` dec´ 2013 Emmanuel Fuchs 1/2 PAST-THALES PARIS 7 contrat de 2009-2012 et 2012-2015

6.1.2 Anciens membres

6.1.2.1 Membres permanents (2007-2011)

Emmanuelle Lebhar CR CNRS depart´ sept 2009, professeur agreg´ e´ Lycee.´ Nicolas Trotignon CR CNRS HdR arrive´ sept 2008, depart´ mars 2011, CR au LIP

6.1.2.2 Stagiaires M2

Amine Abdelkader 2009 Heger Arfaoui 2010 puis these` au LIAFA Herve´ Baumann 2008 puis these` au LIAFA Jean Daligault 2007 puis these` au LIRM Jeremy Dusart 2011 puis these` au LIAFA Quentin Godefroy 2009 Thomas Hujsa 2011 puis these` au LIP6 Marc JeanMougin 2012 Xavier Koegler 2008 puis these` au LIAFA Vincent Liard 2007 Damien Nogues 2009 Stephane Raux 2009 puis these` au LIAFA Theophile´ Trunk 2010

6.1.2.3 Doctorants et post-doctorants (2007-2011)

Doctorants Mohssen Abboud oct 2005-nov 2008 Enseignant-chercheur Syrie Djamal Belazzougui oct 2009-oct 2011 Post-doc groupe Madalgo (Danemark) Anh Phan Hoang jan 2007-oct 2010 IT Consulting Business (Paris) Thomas Hugel sept 2006-dec´ 2010 Post Doc Polytech’Nice at I3S Vincent Limouzy sept 2005-dec´ 2008 MdC Clermont Ferrand Diego Perino nov 2006-nov 2009 Chercheur a` Bell Labs, Alcatel-Lucent. Pascal Pons oct 2004-juil 2007 Chercheur France Telecom Mauricio Soto sept 2007-sept 2011 ATER (Orleans) Alina Stoica oct 2007-oct 2010 Chercheur EDF R&D (these` CIFRE Orange Lab) Andreas Tielmann fev´ 2007-mai 2010 Thu-Hien To sept 2007-oct 2011 Post doc au LIRMM (Montpellier)

120 CHAPITRE 6. ANNEXES : ALGORITHMES DISTRIBUES´ ET GRAPHES

Post-doctorants et ATER Fabien Baille ATER depart´ sept 2007 Eliya Burikkaya 1/2 ATER sept 2009-aoutˆ 2010 Post Doct Tel´ ecom´ Bretagne Julien Clement´ Post-doc Ile de France nov 2009-mars 2011 Analyste quantitatif PEFICAMO Sophis (Paris) Christophe Crespelle ATER sept 2007-aoutˆ 2008 MdC au LIP Stephane Devismes ATER depart´ sept 2007 MdC VERIMAG Philippe Gauron ATER depart´ sept 2007 Ingenieur´ recherche LRI Georges Giakkoupis Post-doc ANR sept 2009-aoutˆ 2011 CR INRIA Asap ALADDIN et PROSE Van Nguyen Post Doc jan 2007-dec 2007 Research assistant. Univ. South Australia Michael¨ Rao ATER depart´ sept 2007 CR2 au LIP Juraj Stacho Post-doc Fondation sept 2008- juil 2009 Post-doc a` Warwick Sciences Math de Paris Ioan Todinca del´ egation´ CNRS Jan 2007-Dec´ 2007 Pr a` l’univ. d’Orleans´ Matejˇ Stehl´ık post-doc jan 2009-aoutˆ 2009 MdC Gscop (Grenoble) Yilma Zelealem post-doc sept 2011-aoutˆ 2012

6.1.2.4 Visiteurs de longue duree´ (2007-2011)

Sam Toueg, Professeur a` l’Universite´ de Toronto, 6 mois de sabbatique (jan 2008-juin 2008).

6.1.2.5 Autres (2007-2011)

Richard Gwin, ingenieur´ sur contrat ANR en 2007

121 CHAPITRE 6. ANNEXES : ALGORITHMES DISTRIBUES´ ET GRAPHES

6.1.3 Visiteurs

Derek Corneil, University of Toronto, Canada 18 mars-26 avril 2009 Pierluigi Crescenzi, University of Florence, Italy 24 nov-23 dec´ 2008 Feodor Dragan, University of Kent, USA sept-dec 2007 Yuval Emek, Tel Aviv University 10-22 mars 2008 et 1-12 dec´ 2008 Eli Gafni, UCLA Los Angeles, USA 14 juin-15 juil 2010 et 14 juin 2011-20 juil 2011 Jerrold Griggs, University of South Carolina at Columbia, USA 11 mai-11 juin 2012 Rachid Guerraoui, EPFL, Suisse 1-30 mars 2008 Hovhannes Harutyunyan, Concordia University, Canada 21-27 fev´ 2011 et 5-15 mars 2012 Maurice Herlihy, University Brown, USA 20 mai-18 juin 2012 Jan van den Heuvel, London School of Economics, UK 1 avril-31 mai 2011 Roman Kolpakov, MGU, Moscou, Russie juin 2007 et juin 2009. MR Dan Kral’,´ Charles University in Prague 4 mois en 2011 and University of West Bohemia in Pilsen, Tchequie.´ Mikel Larrea, Universite´ du Pays Basque, Espagne 2 -13 juil 2009 Zvi Lotker, Ben Gurion University, Israel 1-31 oct 2011. Alessandro Panconesi, University Rome ”La Sapienza”, Italy 1-28 fevrier´ 2010 Andrzej Pelc, Universite´ du Quebec,´ Canada 09-28 mai 2010. David Peleg, Weizmann Institute, Israel 26 oct-3 nov 2009. Sergio Rasjbaum, UNAM Mexico, Mexique 14 juin-20 juil 2011 Juraj Stacho, Universite´ de Toronto 1- 30 sept 2010 Sam Toueg, Universite´ de Toronto, Canada 20 mai-20 juin 2009

6.1.4 Vie de l’equipe´

6.1.4.1 Financements et gestion des ressources

L’equipe´ a obtenu par differentes´ sources l’equivalent´ de 15 annees´ de Post Doc, 34 mois de chercheurs invites´ et 14 ﬁnancements de theses` (dont 2 theses` CIFRE).

2007 2008 2009 2010 2011 2012 2013(dej´ a` obtenu) Bilateraux 4Ke 2Ke 0 1,5Ke 9Ke 8Ke 5,7Ke Nationaux 133Ke 183Ke 204Ke 320Ke 348,5Ke 286,5Ke 191Ke

FIGURE 6.1 – Ressources ger´ ees´ par le LIAFA incluant theses` et post doc sur contrat

6.1.4.2 Vie scientiﬁque

Journees´ – Journees´ a` Barbizon (7 et 8 octobre 2010). Presentation´ des travaux des membres de l’equipe.´ – Laurent Viennot reunit´ une journee´ tous les ans les membres de l’equipe´ Gang pour une presentation´ de leurs resultats´ scientiﬁques. Groupes de travail – BQR ”Algorithmique distribuee´ quantique”, groupe de travail regulier´ en 2009-2010 organise´ par Carole Delporte et Hugues Fauconnier avec des membres de l’equipe´ et des physiciens de

122 CHAPITRE 6. ANNEXES : ALGORITHMES DISTRIBUES´ ET GRAPHES

l’universite´ Paris Diderot. Ces travaux se sont conclus par un workshop de 4 jours ouvert a` d’autres informaticiens et physiciens. – Groupe de travail autour de ”Un algorithme lineaire´ en temps O(n+m) publie´ par Elias Dahlhaus en 2000 [J. Algorithms 36(2) : 205-240] ”, 2007-2009 organise´ par Matthieu Raffinot Les familles partitives se retrouvent naturellement dans la decomposition´ de graphes en arbres, et notamment dans la decomposition´ en coupes, introduite par Cunningham en 1982, qui est une gen´ eralisation´ de la decomposition´ modulaire. Un algorithme lineaire´ en temps O(n + m) a et´ e´ publie´ par Elias Dahlhaus en 2000 [J. Algorithms 36(2) : 205-240]. Cependant personne n’est actuellement capable de certifier si cet algorithme est juste ou non, le papier etant´ tres` confus et tres` mal ecrit.´ Le ref´ er´ e´ principal du papier lui-memeˆ a, de son propre aveu, capitule´ apres` avoir tente´ longtemps de le comprendre et a accepte´ le papier en l’etat.´ M. Raffinot a propose´ debut´ septembre 2007 un groupe de travail sur le sujet. Apres` deux ans passes´ sur le sujet avec ce groupe assez regulier´ (mais qui a perdu des participants en route), nous avons : – extrait, largement simplifie´ et de ce fait rendu utilisable en pratique (un code source est disponible) une perle algorithmique utilisee´ comme sous-routine dans l’algorithme principal pour calculer des classes de recouvrement d’ensembles. Ceci a donne´ lieu a` une note en revue [CHLMRR08]. – finalement reussi´ a` construire un algorithme lineaire´ comprehensible´ pour la decomposition´ en coupes qui emprunte certaines intuitions a` Dalhlaus mais les complemente´ avec de nouvelles. Ces travaux ont recemment´ et´ e´ accepte´ pour publication a` SIAM Journal of Discrete Mathematics [CMR12]. – Groupe de travail ” decorticage´ d’articles” propose´ par Mathieu Raffinot depuis septembre 2011 – Enfin les projets ANR, sont l’occasion a` des sous groupes de l’equipe´ de se reunir´ sur des thematiques´ specifiques.´ Cours Jean-Sebastien´ Sereni et Nicolas Schabanel proposent reguli´ erement` des series´ de cours avances´ (cf section 6.4.3.3) ouverts a` la communaute´ scientifique. Seminaire´ L’equipe´ a un seminaire´ hebdomadaire qui a lieu les mardi apres-midi.` Il a et´ e´ organise´ par Emmanuelle Lebhar, Nicolas Trotignon et Nicolas Schabanel. Il est depuis septembre 2011 organise´ par Pierre Charbit. Intervenants 2012 (19-06-2012) Karell Bertet (Laboratoire L3i, Universite´ de la Rochelle) (12-06-2012) Irena Rusu (LINA - Universite´ de Nantes) (05-06-2012) Mathieu jacomy (Medialab - Sciences Po) (22- 05-2012) Maurice Herlihy (Brown University - Computer Science Department) (15-05-2012) Bernard Ries (LAMSADE - Universite´ Dauphine) (10-04-2012) Pavol Hell (School of Computing Science Si- mon Fraser University), (03-04-2012) Antoine Mamcarz (LIAFA), 13-03-2012) Anthony Perez (LIFO- Universite´ d’Orelans),´ (06-03-2012) Jean Sebastien Sereni (LIAFA), (28-02-2012) Fabien de Montgol- fier (LIAFA), (21-02-2012) Amos Korman (LIAFA), (14-02-2012) Jean-Charles Delvenne (Universite´ Catholique de Louvain), (31-01-2012) Pierluigi Crescenzi (University of Florence), (24-01-2012) Mi- chel Habib (LIAFA). Intervenants 2011 (13-12-2011) Eunjung Kim (Lamsade Paris), (29-11-2011) Abdelhamid Salah Brahim (LIAFA & LIP6), (22-11-2011) Gerth S. Brodal (Aarhus University), (25-10-2011) Dimitrios Thilikos (University of Athens), (18-10-2011) Zvi Lotker (Ben Gurion University of the Negev), (11-10-2011) Henning Bruhn- Fujimoto (Equipe Combinatoire Paris 6), (04-10-2011) Jan Arne Telle (Univ. Bergen), (06-09-2011)- Aharoni (Technion), (28-06-2011) Emilie´ Diot (LaBRI), (21-06-2011) Damien Stelhe´ (LIP, ENS Lyon), 17-05-2011) Mathilde Noual (LIP-IXXI, ENS Lyon), (10-05-2011) Nicolas Bousquet (LIRMM), (03- 05-2011) Florent Becker (LIFO (Orleans)),´ (19-04-2011) Kevin Perrot (LIP-IXXI, ENS Lyon), (15-03- 2011) Dan Kral‘ (Charles University, Prague), (08-02-2011) Alexandre Skoda (Universite´ Paris 1-CES),

123 CHAPITRE 6. ANNEXES : ALGORITHMES DISTRIBUES´ ET GRAPHES

(25-01-2011) Eric Colin de Verdiere` (GeCoaL,´ ENS Paris), (18-01-2011) Claire Mathieu (Brown Uni- versity, Providence, USA), (04-01-2011) Thomas Sauerwald (Max-Planck-Institut fur¨ Informatik). Intervenants 2010 (21-12-2010) Ryan Hayward (University of Alberta), (30-11-2010) Antoine Deza (McMaster University, Hamilton, Ontario, Canada), (23-11-2010) Nicolas Schabanel (LIAFA), (16- 11-2010) Roberto Mantaci (LIAFA), (09-11-2010) Marko Radovanovic (Union University, Belgrade), (02-11-2010) Guillaume Chapuy (LIAFA), (13-10-2010) Steven Chaplick (University of Toronto), (12- 10-2010) Pierluigi Crescenzi (University of Florence), (05-10-2010) Amos Korman (LIAFA), (28-09- 2010) Juraj Stacho (LIAFA), (06-07-2010) Steve Chaplick (University of Toronto), (06-07-2010) Eli Gafni (UCLA), (08-06-2010) Stephane´ Bessy (LIRMM), (25-05-2010) Andrzej Pelc (Universite´ du Quebec´ en Outaouais), (19-05-2010) Henning Bruhn-Fujimoto (Nihon University), (18-05-2010) Mauro Sozio (Max-Planck-Institut fur¨ Informatik), (11-05-2010) Andras´ Sebo˘ (G-SCOP, Grenoble), (04-05- 2010) Jean-Sebastien´ Sereni (LIAFA), (27-04-2010) Xavier Buchwalder (30-03-2010) Stephane´ Vialette (Universite´ Paris Est-Institut Garpard Monge), (23-03-2010) Guilhem Fouetillou (Linkﬂuence), (16-03- 2010) Bernard Monjardet (CES, Universite´ Paris 1) (09-03-2010) Djamal Bellazzougui (LIAFA) (02- 03-2010) David Ilcinkas (LABRI, Bordeaux) (26-02-2010) Alessandro Panconesi (Sapienza Universita, Roma), (23-02-2010) Gena Hahn (16-02-2010) Corentin Travers (LIP6, INRIA), (09-02-2010) Arnaud Labourel (LABRI, Bordeaux), (02-02-2010) Ioan Todinca (LIFO, Orleans),´ (26-01-2010) Selma Djel- loul (LRI, Orsay), (26-01-2010) Jayme L Szwarcﬁter (Universidade Federal do Rio de Janeiro, Brasil), (19-01-2010) Adria Lyra (Universidade Federal Fluminense), (12-01-2010) Nicolas Trotignon (LIAFA), (05-01-2010) Laurent Viennot (LIAFA). Intervenants 2009 (15-12-2009) Maria Chudnovsky (Columbia University), (08-12-2009) Andreas Tielmann (LIAFA), (30-11-2009) Celina de Figueiredo (Universidade Federal do Rio de Janeiro), (24-11-2009) Pierre Charbit (LIAFA), (10-11-2009) Julien Clement´ (LIAFA), (03-11-2009) Martin Loebl (Dept. of Ap- plied Math., Charles University, Republique´ Tcheque),` (27-10-2009) Nicolas Lichiardopol (IUT Sa- lon), (20-10-2009) Amos Korman (LIAFA), (13-10-2009) Jean-Sebastien´ Sereni (LIAFA), (29-09-2009) Ross Kang (McGill University), (07-07-2009) Matej˘ Stehl´ık (LIAFA), (07-07-2009) Jean-Sebastien´ Se- reni (LIAFA), (30-06-2009) Kristina Vuskovic (University of Leeds), (16-06-2009) Roman Kolpakov (Lomonosov Moscow State University, Moscou), (09-06-2009) Michael Rao (LABRI, Bordeaux), (09- 06-2009) Raphael Machado (Universidade Federal do Rio de Janeiro), (02-06-2009) Guyslain Naves (G-SCOP, Grenoble), (05-05-2009) Omid Amini (DMA, ENS Paris), -(28-04-2009) P. Dorbec, P. Frai- gniaud, M. Habib, V. Jost et F. Mercier (10-04-2009) Derek Corneil (University of Toronto), (31-03- 2009) Benjamin Lev´ equeˆ (LIF, Marseille), 17-03-2009) Kathie Cameron (LIP6, Paris) 03-03-2009) Olivier Hudry (ENST,Paris) 24-02-2009) Guillaume Valadon (LIP6), (24-02-2009) Guanghui Wang (Shandong University et Ecole Centrale Paris), 17-02-2009/2009-02-17 Fred´ eric´ Havet (Projet MAS- COTTE, I3S (CNRS-UNSA)-INRIA), (03-02-2009) Cedric´ Bentz (LRI, Orsay), (27-01-2009) Matej˘ Stehl´ık (LIAFA), (20-01-2009) Juraj Stacho (LIAFA), (13-01-2009) Zsolt Tuza (Hungarian Academy of Sciences and University of Pannonia, Hungary), (13-01-2009) Srecko Brlek (UQAM), (06-01-2009) Jean-Sebastien´ Sereni (LIAFA). Intervenants 2008 (16-12-2008) Christoph Durr¨ (LIX), (09-12-2008) David Auger (MIC2, Tel´ ecom´ Paris), (04-12-2008) Dan Kral’´ (Charles Univeristy, Prague, Czech Republic), (02-12-2008) Cedric´ Bentz (LRI, Orsay), (04- 11-2008) Fred´ eric´ Meunier (LVMT, Ponts et Chaussees),´ (28-10-2008) Ha Duong Phan (LIAFA), (21- 10-2008) Andras Gyarfas (Hungarian Academy of Science), (16-10-2008) Matthias Bernt (University of Leipzig), (30-09-2008) Bernard Kouakou (Centre d’Economie´ de la Sorbonne), (24-06-2008) Olivier Bernardi (Departement´ de Mathematiques-Orsay),´ (17-06-2008) Christophe Prieur (LIAFA), (10-06- 2008) Vijaya Ramachandran (University of Texas (Austin, USA)), (13-05-2008) Fred´ eric´ Magniez (LRI-

124 CHAPITRE 6. ANNEXES : ALGORITHMES DISTRIBUES´ ET GRAPHES

Orsay), (06-05-2008) Fred´ erique´ Bassino (Institut Gaspard Monge, Univ. Paris Est) (06-05-2008) Tobias Muller¨ (Technische Universiteit Eindhoven) (29-04-2008) Mathieu Liedloff (LITA-Metz), (22-04-2008) Pascal Ochem (LRI-Orsay), (17-04-2008) Sam Toueg (Toronto Univ (invite´ LIAFA)) (15-04-2008) Ber- trand Estellon (LIF-Marseille), (08-04-2008) Eric Angel (LaMI, Universite´ d’Evry) (01-04-2008) Ores- tis Telelis (Aarhus University, Denmark) (25-03-2008) Binh-Minh Bui-Xuan (LIRMM-Montpellier), (18-03-2008) Nazim Fates` (LORIA), (18-03-2008) Mark Tedder (University of Toronto), (11-03-2008) Jean-Sebastien´ Sereni (Institute for theoretical computer science, Charles Univ. (Prague, Rep.´ Tcheque))` (11-03-2008) Derek Corneil (University of Toronto), (04-03-2008) Michael¨ Rao (LIRMM-Montpellier), (26-02-2008) Philippe Nadeau (Fakultat¨ fur¨ Mathematik-Universitat¨ Wien), (19-02-2008) Steve Y. Ou- dot (Leonidas Guibas Laboratry, Standford University), (12-02-2008) Sandrine Vial (PRISM (CNRS et Univ. Versailles)), (05-02-2008) Stephane´ Le Roux (INRIA-Microsoft research), (29-01-2008) Eric Tannier (INRIA Rhone-Alpesˆ (projet Helix)´ & Univ. Lyon I), (22-01-2008) Marie Albenque (LIAFA), (08-01-2008) Philippe Robert (INRIA Rocquencourt (projet RAP)), Intervenants 2007 (18-12-2007) Benjamin Levequeˆ (G-SCOP (Grenoble)), (12-12-2007) Victor Chepoi (Laboratoire d’In- formatique Fondamentale-Marseille) (21-11-2007) Laurent Gourves` (LAMSADE (Paris Dauphine)), (30-10-2007) Jean-Loup Guillaume (LIP6), (23-10-2007) Thomas Fernique (LIRMM (Montpellier)), (10-10-2007) Christophe Crespelle (LIAFA), (02-10-2007) Feodor Dragan (Kent State University (dept of CS)), (10-07-2007) Nicolas Schabanel (CNRS, LIP (ENS Lyon) et CMM (Univ. de Chile)), (10- 07-2007) Vassilis Giakoumakis (LaRIA (Univ. Amiens)), (03-07-2007) Johann Makowsky (Technion (Israel)),¨ (03-07-2007) Dimitrios M. Thilikos (National and Capodistrian University of Athens), (26-06- 2007) Etienne Grandjean (GREYC, U. Caen), (19-06-2007) Pascal Prea´ (LIF et Ecole Centrale (Mar- seille)), (12-06-2007) Gerard´ Cornuejols ( LIF (Marseille)), (05-06-2007) Philippe Nadeau (LIAFA), (29-05-2007) Vassily Lyubetsky (Institute for information transmission problems of RAS (Moscou)), (22-05-2007) Jer´ emie´ Chalopin (LaBRI (Bordeaux)), (16-05-2007)Tran Thi Thu Huong (Vietnam Ins- titute of Mathematics (Hanoi)), (15-05-2007) Fred´ eric´ Meunier (INRIA Rocquencourt (projet Algo)), (09-05-2007) Pierre Peterlongo (IRISA (Rennes)), (24-04-2007) Ioan Todinca (LIFO (en del´ egation´ CNRS au LIAFA)), (03-04-2007) Sylvain Gravier (CNRS, lab. Leibniz, IMAG (Grenoble)), (27-03- 2007) Fred´ eric´ Jouhet (Institut Camille Jordan (Univ. Lyon 1)), (20-03-2007)Van Nguyen (CNRS, LIAFA), (14-03-2007) Paolo Boldi (University of Milano), (13-03-2007) Yann Vaxes` (LIF (Marseille)), (06-03-2007) Nicolas Thibault (IBISC (Evry)), (27-02-2007) Sylvain Perifel (LIP (ENS Lyon)), (20- 02-2007) Stefan de Wannemacker (UCD (Dublin)), (13-02-2007) Zvi Lotker (Communication Systems dept, Ben Gurion University, Beer Sheva, ISRAEL), (05-02-2007) Stephan Thomasse (LIRMM (Mont- pellier)), (30-01-2007) Nicolas Trotignon (CERMSEM, U. Paris 1), (23-01-2007) Fred´ eric´ Havet (Projet Mascotte, INRIA Sophia), (16-01-2007) Dieter Kratsch (LITA (Metz)), (09-01-2007) Stephane Vialette (LRI).

6.1.4.3 Implication dans l’animation scientiﬁque et les responsabilites´ administratives locales, nationales et internationales

Yacine Boufkhad est directeur des etudes´ de 1ere` annee´ a` l’IUT Paris Jussieu depuis 2007. Pierre Charbit est responsable du Master 2 PISE (Projets Informatiques et Strategie´ d’Entreprise). Ce cursus s’adresse exclusivement aux etudiants´ en sciences humaines et sociales. Carole Delporte est responsable du Master 2 Pro Ingenierie´ Informatique (depuis 2006), co-responsable de la mention Master Informatique (depuis mai 2012) et directrice adjointe de l’UFR (depuis avril 2012). Hugues Fauconnier est responsable du L3 de la Licence d’informatique (depuis 2006), responsable de la mention Licence (depuis avril 2012) et membre elu´ au conseil d’administration de l’universite.´

125 CHAPITRE 6. ANNEXES : ALGORITHMES DISTRIBUES´ ET GRAPHES

Michel Habib a et´ e´ directeur du LIAFA de janvier 2008 jusqu’au 31 decembre´ 2009. Pierre Fraigniaud est depuis directeur du LIAFA. A la demande d’Arnold Migus Directeur Gen´ eral´ du CNRS, Michel Habib a et´ e´ le premier directeur du 10eme institut du CNRS : l’Institut des Sciences Informatique et leurs Interactions (INS2I) (de septembre 2009 a` Mars 2010). Laurent Viennot est responsable de l’equipe-projet´ INRIA Gang.

Nicolas Schabanel est co-responsable du GT CoA (Complexite´ et Algorithmes) du GdR IM (depuis 2011). Nicolas Schabanel est co-organisateur du trimestre mathematique´ et informatique ”Metric 2011” a` l’Ins- titut Henri Poincare,´ janvier-mars 2011.

Jaroslav Nesetˇ rilˇ (CZ) et Jean-Sebastien´ Sereni (FR) sont responsables de STRUCO, laboratoire europeen´ associe´ du CNRS qui regroupe le LIAFA (CNRS et Univ. Paris Diderot) et IUUK (Institut d’In- formatique, Univ. Charles de Prague). 6.2 Contrats et projets scientiﬁques

6.2.1 Responsabilites´ de projets internationaux

Projet Germaine de Stael¨ (2007-2008) Type de projet : Partenariat Hubert Curien. Titre detaill´ e´ : Reseaux´ de capteurs. Partenaires : LIAFA et LPD (EPFL). Responsable : Hugues Fauconnier. Montant de la collaboration (pour le LIAFA) : 4Ke. Projet Procope (2006-2007) Type de projet : Partenariat Hubert Curien. Titre detaill´ e´ : Securit´ e´ et Al- gorithmique Distribuee.´ Partenaires : LIAFA et Universite´ de Mannheim. Responsable : Hugues Fauconnier. Montant de la collaboration (pour le LIAFA) : 4Ke. Projet Barrande 24444XD (2011-2013) Type de projet : Partenariat Hubert Curien. Titre detaill´ e´ : Ap- proches algebriques´ de problemes` combinatoires — couplages parfaits, permanents et polynomesˆ hyperboliques. Partenaires : LIAFA, Dept. de Mathematiques´ de l’Univ. de Boheme` de l’ouest (Plzen) et Institut d’Informatique de l’Universite´ Charles (Prague). Responsable : Jean-Sebastien´ Sereni. Montant de la collaboration (pour le LIAFA) : 5,7Ke. Projet Proteus 26818PC (2012-2014 ). Type de projet : Partenariat Hubert Curien. Titre detaill´ e´ : Graphes pour la chimie combinatoire et les reseaux´ complexes Partenaires : LIAFA et Dept. de Mathematiques,´ Univ. de Ljubljana. Responsable : Jean-Sebastien´ Sereni. Montant de la collaboration (pour le LIAFA) : 2Ke. Projet Architectures multicoeurs et algorithmique distribuee´ (2011-2013) Type de projet : PICS bilateral´ Franco-Suisse. Partenaires : LIAFA et LPD (EPFL). Responsable : Carole Delporte et Hugues Fauconnier. Montant de la collaboration (pour le LIAFA) : 15 Ke. COST 295-Dynamo (2004-2008) Type de projet : programme European COST (European Coopera- tion in the Field of Scientiﬁc and Technical Research) du domaine Telecommunications, Informa- tion Science and Technology domain (TIST). Responsable : Pierre Fraigniaud. co-Resp. Working Group 1 (Small Worlds) : Nicolas Schabanel. Montant total de la collaboration : 150 Ke. Ce projet n’est pas ger´ e´ par le LIAFA.

6.2.2 Responsabilite´ de projets nationaux

Projet HEREDIA (2011-2015). Type de projet : ANR JC. Titre detaill´ e´ : Hereditary Classes of Graphs. Partenaires : LIAFA (CNRS et Univ. Diderot). Responsable du projet : Jean-Sebastien´ Sereni.

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Montant de la collaboration (pour le LIAFA) : 212Ke. Projet ALADDIN (2007-2011). Type de projet : ANR Blanc. Titre detaill´ e´ : Algorithm Design and Analysis for Implicitly and Incompletely Deﬁned Interaction Networks. Partenaires : LIAFA (CNRS et Univ. Diderot) et LaBRI (CNRS et Univ. Bordeaux). Responsable du projet : Pierre Fraigniaud. Montant de la collaboration (pour le LIAFA) : 450Ke. Projet GRAAL (2006-2009). Type de projet : ANR Blanc. Titre detaill´ e´ : Graph Decomposition and Algolrithms. Partenaires : LIAFA (CNRS et Univ. Diderot), LaBRI (CNRS et Univ. Bordeaux) and LIRMM( CNRS, Univ de Montpellier). Responsable du projet : Michel Habib. Montant de la collaboration (pour le LIAFA) : 66Ke. Projet DynaDraw (2009-2011). Type de projet : PEPS CNRS. Titre detaill´ e´ : Representation´ Statique des Aspects Dynamiques des Graphes d’Interaction. Partenaires : LIAFA (CNRS et Univ. Paris Diderot), LIMOS (CNRS et Univ. Clermont Ferrand), et CPT (CNRS et Univ. Marseille). Res- ponsable du projet : Nicolas Schabanel. Montant de la collaboration : 14Ke. Projet Mappi (2010-2013). Type de projet : ANR Cosinus. Titre detaill´ e´ : Nouvelles approches algorithmiques et bioinformatiques pour l’analyse des grandes masses de donnees´ issues des sequenceurs´ de nouvelle gen´ eration.´ Partenaires : LIAFA (CNRS et Univ. Diderot), INRIA Bonsai (LIFL Lille), INRAI Symbiose (IRISA Rennes), Genoscope (CEA, Evry). Responsable du projet : Mathieu Rafﬁnot. Montant de la collaboration : 150 Ke. Projet Buenos Aires 1620–1840 (2011-2012). Type de projet : PEPS INS2I-SHS (interdisciplinaire). Titre detaill´ e´ : constitution d’un corpus pour l’etude´ de la dynamique des reseaux´ sociaux personnels et la formation d’une communaute.´ Partenaires : LIAFA, SEDET (CNRS et Univ. Diderot), CRH (CNRS et EHESS), LIF (CNRS et Aix-Marseille 2). Responsable du projet : Christophe Prieur. Montant pour le LIAFA : 12Ke. Projet DISPLEXITY (2011-2014). Type de projet : ANR Blanc. Titre detaill´ e´ : Calculabilite´ et complexite´ en distribue.´ Partenaires : LIAFA (CNRS et Univ. Diderot), LaBRI (CNRS et Univ. Bor- deaux) et ASAP (INRIA-Bretagne). Responsable du projet : Carole Delporte et Hugues Faucon- nier. Montant de la collaboration (pour le LIAFA) : 283Ke.

6.2.3 Participation a` des projets internationaux

Projet Multicomputing (2009-2011) Type de projet : MAE bilateral´ Franco-Israelien.´ Partenaires : Weizmann Institute, Technion, LaBRI et LIAFA. Responsable LIAFA : Pierre Fraigniaud. Projet Jules Verne (2010-2011) Type de projet : PHP bilateral´ Franco-Islandais. Partenaires : LIAFA et universite´ de Reykjavik. Responsables LIAFA : Pierre Fraigniaud et Franc¸ois Laroussinie. Mon- tant de la collaboration : 3Ke. Projet Pavle Savic´ (2010) Type de projet : PHP bilateral´ Franco-Serbe. Partenaires : LIAFA et universite´ de Belgrade. Responsable LIAFA : Nicolas Trotignon. Experimental UpdateLess Evolutive Routing (EULER)(2010-2013) Type de projet : STREP. Partenaires : INRIA, Alcatel, UPMC, UCL, IBBT, RACTI, CAT. http://www. euler-fire-project.eu/. Responsable LIAFA : Laurent Viennot.

Autres participation a` des projets internationaux Projet MSM 0021620838 du Ministere` tcheque` de l’Education.´ Responsable : Jan Kratochv´ıl, Departement´ de Mathematiques´ appliquees´ de l’Universite´ Charles de Prague. Participation : Jean- Sebastien´ Sereni. MANCOOSI (2008-2011) : Projet europeen´ Universite´ Paris Diderot, Universite´ de Nice, INESC Por- tugal, Caixa Magica, Mandriva, ILOG, Universite´ de Tel-aviv et Universite´ de Louvain. Respon- sable :Roberto Di Cosmo(PPS). Participation : Yacine Boufkad.

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6.2.4 Participation a` des projets nationaux

FRAGILE (2004-2008). Type de projet : ACI Securit´ e.´ Titre detaill´ e´ : Failure Resilience and Applica- tion Guaranteed Integrity in Large-scale Environments). Partenaires : LIAFA, LRI. Responsable du projet : Sebastien´ Tixeuil (LRI). Responsable LIAFA : Hugues Fauconnier. Montant de la collaboration (pour le LIAFA) : 55Ke. Autograph (2006-2008). Type de projet : ANR Tel´ ecom.´ Titre detaill´ e´ :Visualisation et analyse des col- lectifs auto-organises.´ Partenaires : Orange Labs, LIAFA, Inria Futues, ENST, Fing. Responsable du projet : Dominique Cardon (Orange Labs). Responsable LIAFA : Christophe Prieur. Montant de la collaboration (pour le LIAFA) : 110Ke. Projet PROSE (2009-2012). Type de projet : ANR VERSO. Titre detaill´ e´ : Content Shared Through P2P Recommendation & Opportunistic Social Environment. Partenaires : Thomson (Paris), IN- RIA Regal (Paris), Eurecom´ (Sophia-Antipolis), PlayAdz (Sophia-Antipolis), LIAFA (Paris), Te- lecom ParisTech (Paris). Responsable du projet : Augustin Chaintreau (Thomson). Responsable LIAFA : Pierre Fraigniaud. Montant de la collaboration (pour le LIAFA) : 87Ke. Projet SHAMAN (2009-2012). Type de projet : ANR VERSO. Titre detaill´ e´ : Self-organizing and Hea- ling Architectures for Malicious and Adversarial Networks. Partenaires : LIP6(Paris), LIAFA (Pa- ris), INRIA ASAP (Rennes), Ecole Polytechnique et LIF, Orange Labs (Paris). Responsable du projet : Sebastien´ Tixeuil (Lip6). Responsable LIAFA : Hugues Fauconnier. Montant de la collaboration (pour le LIAFA) : 117Ke. Peficamo (2009-2011) Type de projet : projets DIM ”Logiciels et Systemes` Complexes” 2009 de la Region´ Ile-de-France.ˆ Titre detaill´ e´ : Performance et fiabilite´ des reseaux´ de capteurs mobiles. Partenaires : LIAFA, LPD(EPFL), LSV. Responsable LIAFA : Hugues Fauconnier Montant de la collaboration (pour le LIAFA) : 138Ke. Projet AutProb (2010-2012). Type de projet : projet IXXI. Titre detaill´ e´ : Reseaux´ d’automates probabilistes. Partenaires : LIAFA (CNRS et Univ. Diderot), LIP (CNRS et ENS Lyon), LIG (CNRS et Grenoble), Leibniz U. Hannover, LJK (CNRS et Grenoble). Montant de la collaboration : 5Ke. Resp. : Eric´ Thierry, Nicolas Schabanel. Algopol (2012-2014). Type de projet : ANR Contenus et Interactions. Titre detaill´ e´ : Politique des algorithmes. Partenaires : LIAFA, Cams (EHESS/CNRS), Linkfluence, Orange Labs. Responsable du projet : Camille Roth (ISC-PIF). Responsable LIAFA : Christophe Prieur. Montant de la collaboration (pour le LIAFA) : 120Ke.

Autres participation a` des projets nationaux : Webﬂuence (2009-2010). Type de projet : ANR Systemes` complexes. Titre detaill´ e´ : Dynamique d’opi- nion dans les espaces publics numeriques´ : morphogenese` et diffusion. Partenaires : Institut des systemes` complexes Paris Ile de France, Lip6, Linkﬂuence, Orange Labs Responsable du projet : Camille Roth (ISC-PIF). Christophe Prieur etait´ associe´ au Lip6 (responsable Ben´ edicte´ Le Grand). Projet MAGNUM (2010-2014). Type de projet : ANR Blanc. Titre detaill´ e´ : Methodes´ Algorithmiques pour la Gen´ eration´ aleatoire´ Non Uniforme : Modeles` et applications. Partenaires : LIAFA (CNRS et Univ. Diderot), LIP6 (CNRS et Univ. Pierre et Marie Curie), LIX (CNRS et Ecole´ Polytech- nique), INRIA Rocquencourt, IGM (CNRS et Univ. Paris Est) et LIPN (CNRS et Univ. Paris Nord). Responsable du projet : Michele` Soria. Participant : Nicolas Schabanel.

6.2.5 Participation a` des projets locaux

Projet AlgoSysComp (2009-2010). Type de projet : BQR. Titre detaill´ e´ : Aspects algorithmiques des systemes` complexes naturels. Partenaires : LIAFA (CNRS et Univ. Diderot). Responsables du

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projet : Nicolas Schabanel. Montant de la collaboration : 20Ke. Projet Algorithmique distribuee´ quantique (2010). Type de projet : Projet Interdisciplinaire Paris Diderot. Partenaires : LIAFA et le Laboratoire Materiaux´ et Phenom´ enes` Quantiques (MPQ) de l’universite´ Paris Diderot. Responsables du projet : Carole Delporte et Hugues Fauconnier (LIAFA) et Thomas Coudreau (MPQ). Montant de la collaboration : 12 Ke.

6.3 Administration de la recherche

6.3.1 Activitees´ editoriales´

6.3.1.1 Membre de comites´ editoriaux´

Distributed Computing (Springer). Pierre Fraigniaud (2008-actuel). Voir http://www.springer.com/computer/communications/journal/446 Theory of Computing Systems (Springer). Pierre Fraigniaud (2003-actuel). Voir http://www.springer.com/computer/foundations/journal/224 Fundamenta Informaticae (IOS Press). Pierre Fraigniaud (2010-actuel). Voir http ://ﬁ.mimuw.edu.pl/. ICST Transactions on Algorithms Engineering. Pierre Fraigniaud (2009-actuel). Voir http://icst.org/algorithms-engineering/ Journal of Interconnection Networks (World Scientiﬁc). Pierre Fraigniaud (2002-actuel). Voir http://www.worldscinet.com/join/mkt/editorial.shtml Mathematica Bohemica (Academie des Sciences de Republique´ Tcheque).` Jean-Sebastien´ Sereni (2011-actuel). Voir http ://mb.math.cas.cz/

6.3.1.2 Edition de numeros´ speciaux´

Theoretical Computer Science (Elsevier). Numero´ special´ “Graph Searching”. Pierre Fraigniaud (vol 399, Number 3, 2008) en collaboration avec Fedor Fomin (Univ. Bergen) et Dimitrios Thilikos (Univ. Athenes).`

6.3.2 Gestion scientiﬁque de conferences´

6.3.2.1 Presidence´ de comites´ de pilotage

SIROCCO. Colloquium on Structural Information and Communication Complexity. Pierre Fraigniaud (2006-2011).

6.3.2.2 Participation a` des comites´ de pilotage

DISC. International Conference on Distributed Computing. Pierre Fraigniaud (2005-2008). PODC. ACM Symposium on Principles of Distributed Computing. Pierre Fraigniaud (2011-actuel). STACS. Symposium on Theoretical Aspects of Computer Science. Pierre Fraigniaud (2004-2009) et Michel Habib (2005-2010) SPAA. ACM Symposium on Parallelism in Algorithms and Architectures. Pierre Fraigniaud (2002- actuel). WG. International Workshop on Graph- Theoretic Concepts in Computer Science. Michel Habib (2004- 2011)

129 CHAPITRE 6. ANNEXES : ALGORITHMES DISTRIBUES´ ET GRAPHES

6.3.2.3 Presidence´ de comites´ de programme

PODC 2011 30th ACM Symp. on Principles of Distributed Computing, San Jose, USA, Jun 6-8, 2011. Pierre Fraigniaud. Algotel 2012 14emes` Rencontres Francophones sur les Aspects Algorithmiques des Tel´ ecommunications´ 29 Mai au 1er Juin 2012, La Grande Motte, Herault,´ France. Fabien Mathieu (avec Nicolas Hanusse).

6.3.2.4 Participation a` des comites´ de programmes

Conferences´ internationales PODS 2013 (External Review Committee). 32th ACM SIGMOD-SIGACT-SIGART Symposium on Prin- ciples of Database Systems, New York, June 23-28, 2013. Pierre Fraigniaud. PODC 2012 31th ACM SIGACT-SIGOPS Symposium on Principles of Distributed Computing, Ma- deira, Portugal July 16-18, 2012. Carole Delporte-Gallet. ICALP 2012 39th International Colloquium on Automata, Languages and Programming, Warwick, UK, July 9-13, 2012. Pierre Fraigniaud. ICDCS 2012. 32nd International Conference on Distributed Computing Systems, Kanazawa, Japan, 12- 25 June 2012. Carole Delporte-Gallet, Hugues Fauconnier, Pierre Fraigniaud et Amos Korman. SSS 2012. 14th International Symposium on Stabilization, Safety, and Security of Distributed Systems, Toronto, Canada, September 24-27, 2012. Pierre Fraigniaud. ALGOSENSORS 2012. 8th International Symposium on Algorithms for Sensor Systems, Wireless Ad Hoc Networks and Autonomous Mobile Entities, Ljubljana, Slovenia, September 2012. Pierre Frai- gniaud. ITC 2012 24th International Teletraffic Congress, Krakow, Poland, September 4-7, 2012, Fabien Ma- thieu SEA 2012. 11th Symposium on Experimental Algorithms, Bordeaux, France, June 7-9, 2012. Pierre Fraigniaud. LATA 2012 6th Int. Conf. on Language and Automata Theory and Applications , Coruna, SpainMarch 5-9, 2012. Mathieu Raffinot. TAPAS 2012. 2nd International Conference on Theory and Practice of Algorithms in (Computer) Sys- tems, Ein Gedi, Israel, December 3-5, 2012. Pierre Fraigniaud. SWAT2012 13th Scandinavian Symposium and Workshops on Algorithm Theory Helsinki, Finland, July 4-6,2012. Michel Habib. LATIN 2012 10th Latin American Symposium on Theoretical Informatics, Arequipa, Perou, April 16- 20, 2012. Nicolas Schabanel. SEA 2012 11th International Symposium on Experimental Algorithms, Bordeaux, France, June 7-9, 2012. Nicolas Schabanel. ICDCN 2012 13th International Conference on Distributed Computing and Networking, Hong Kong, China January 3-6, 2012. Carole Delporte-Gallet. CPM 2012 23 th Annual Symposium Combinatorial Pattern Matching July 3-5, 2007, Helsinki, Fin- land. Mathieu Raffinot. PODC 2011 30th ACM Symp. on Principles of Distributed Computing, San Jose, USA, Jun 6-8, 2011. Amos Korman SPAA 2011 23rd ACM Symposium on Parallelism in Algorithms and Architectures, San Jose, Califor- nia, USA, June 4-6, 2011. Pierre Fraigniaud.

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ICDCN 2011 12th International Conference on Distributed Computing and Networking, Bangalore, India, Jan 02-05, 2011. Pierre Fraigniaud. IPDPS 2011 25th IEEE International Symposium on Parallel and Distributed Processing, Anchorage, Alaska, USA, 16-20 May, 2011. Fabien Mathieu et Laurent Viennot LATA 2011 5th Int. Conf. on Language and Automata Theory and Applications (LATA) Taragone, Spain, 26-31 May, 2011. Mathieu Rafﬁnot. OPODIS 2010 14th International Conference Principles of Distributed Systems , Tozeur, Tunisia, De- cember 14-17, 2010. Carole Delporte-Gallet. SSS 2010 12 th International Symposium on Stabilization, Safety, and Security of Distributed Systems New York City, USA September 20-22, 2010. Hugues Fauconnier. DISC 2010 24th International Symposium on Distributed Computing, September 12-15, 2010, Cam- bridge, USA. Pierre Fraigniaud. APPROX 2010 13th Intl. Workshop on Approximation Algorithms for Combinatorial Optimization Problems, 1-3 September 2010, UPC Barcelona, Spain. Pierre Fraigniaud. PODC 2010 29th ACM SIGACT-SIGOPS Symposium on Principles of Distributed Computing, Zurich, Switzerland July 25-28, 2010. Hugues Fauconnier. ICDCS 2010 30th International Conference on Distributed Computing Systems, Jun 21-25, 2010, Ge- noa, Italy. Pierre Fraigniaud. WOSN 2010 3rd Workshop on Online Social Networks, June 22, 2010, Boston, MA, USA. Pierre Frai- gniaud. WG 2010 36th International Workshop on Graph Theoretic Concepts in Computer Science, June 28-30, 2010, Zaros,´ Crete, Greece. Pierre Fraigniaud. ACA 2010 1st Asynchronous Cellular Automata Workshop part of ACRI 2010 (9th Int. Conf. Cellu- lar Automata for Research and Industry), Ascoli Piceno, Italy, September 21-24, 2010. Nicolas Schabanel. ICDCN 2010 11th International Conference on Distributed Computing and Networking, January 3-6, 2010, Kolkata, India. Pierre Fraigniaud et Amos Korman. MFCS 2010 35th International Symposium on Mathematical Foundations of Computer Science, Au- gust 23-27, 2010 Brno, Czech Republic. Michel Habib. SSS 2009 11th International Symposium on Stabilization, Safety, and Security of Distributed Systems Lyon, France, November 3-6, 2009. Hugues Fauconnier et Fabien Mathieu DISC 2009 23th Annual Conference on Distributed Computing. Elche/Elx, Spain, September 23-25, 2009 Carole Delporte-Gallet. PODC 2009 28th ACM SIGACT-SIGOPS Symposium on Principles of Distributed Computing, Calgary, Canada, August 10-12, 2009. Pierre Fraigniaud. MFCS 2009 34th International Symposium on Mathematical Foundations of Computer Science, Au- gust 24-28, 2009 Novy Smokovec, Slovakia. Pierre Fraigniaud. ICALP 2009 36th International Colloquium on Automata, Languages and Programming, July 5-12, 2009 Rhodes, Greece. Track A ”Algorithms, Automata, Complexity and Games”, Michel Ha- bib.Track C ”Foundations of Networked Computation”, Pierre Fraigniaud. ESA 2009 17th Annual European Symposium on Algorithms, Sept. 7-9, 2009, Copenhagen. Pierre Frai- gniaud. IPDPS 2009 23rd IEEE International Parallel and Distributed Processing Symposium, Rome, Italy, May 25-29, 2009. Pierre Fraigniaud.

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ICDCN 2009 10th International Conference on Distributed Computing and Networking, January 3-6, 2009, Gachibowli, Hyderabad, India. Pierre Fraigniaud. SSS 2009 11th International Symposium on Stabilization, Safety, and Security of Distributed Systems, Lyon, France, November 3-6, 2009. Pierre Fraigniaud et Fabien Mathieu. WAOA 2009 7th Int. Workshop on Approximation and Online Algorithms, Copenhagen, Denmark, Sep- tember 10-11, 2009. Nicolas Schabanel. DISC 2008 22nd International Symposium on Distributed Computing, Arcachon, France. September 22-24, 2008. Amos Korman. DIALM-POMC 2008 5th ACM Int. Workshop on Foundation of Mobile Computing, August 22, 2008, Toronto, Canada. Pierre Fraigniaud. ICDCS 2008 28th Int. Conference on Distributed Computing Systems, Beijing, 17-20 june 2008. Pierre Fraigniaud. SPIRE 2008 15th String Processing and Information Retrieval Symposiu, Melbourne, Australia, No- vember 10-12 2008. Mathieu Rafﬁnot. PODC 2007 26 th ACM Symposium on Principles of Distributed Computing, August 13-15, 2007, Port- land, Oregon. Pierre Fraigniaud. MFCS 2007 32nd Int. Symp. on Mathematical Foundations of Computer Science, Cesky Krumlov, Czech Republic, August 26-31, 2007. Pierre Fraigniaud. SASO 2007 1st IEEE International Conference on Self-Adaptive and Self-Organizing Systems, July 9- 11, 2007, MIT, Boston, USA. Pierre Fraigniaud. ADHOCNOW 2007 6th International Conference on Ad Hoc and Wireless Networks, Morelia, Mexico, September 24-26, 2007. Pierre Fraigniaud. ICPP 2007 36th International Conference on Parallel Processing, XiAn, China September 10-14, 2007. Pierre Fraigniaud. MASS 2007 4th IEEE International Conference on Mobile Ad-hoc and Sensor Systems, Pisa, 8-11 Oc- tober 2007. Pierre Fraigniaud. DIALM-POMC 2007 4th ACM Int. Workshop on Foundation of Mobile Computing, August 16, 2007, Portland, Oregon. Pierre Fraigniaud. Euro-Par 2007 13th International European Conference on Parallel and Distributed Computing, Rennes, France, August 28-31, 2007. Nicolas Schabanel. CPM 2007 18 th Annual Symposium Combinatorial Pattern Matching, July 9-11, 2007, London, Ca- nada. Mathieu Rafﬁnot. Conferences´ nationales Algotel 2012 14emes` Rencontres Francophones sur les Aspects Algorithmiques de Tel´ ecommunications.´ 29 Mai au 1er Juin 2012, La Grande Motte, Herault,´ France. Hugues Fauconnier, Nicolas Schabanel. JGA 2011–present´ Journees´ Graphes et Algorithmes du GDR IM Jean-Sebastien´ Sereni. Algotel 2011 13emes` Rencontres Francophones sur les Aspects Algorithmiques de Tel´ ecommunications.´ 23 au 26 Mai 2011, Cap Esterel,´ France. Carole Delporte-Gallet et Nicolas Schabanel. Algotel 2010 12emes` Rencontres Francophones sur les Aspects Algorithmiques de Tel´ ecommunications.´ 31Mai -3 Juin 2010, Belle Dune, Cote d’Opale, France. Hugues Fau- connier

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JDIR 2010 11es Journees´ Doctorales en Informatique et Reseaux´ 24-26 Mars 2010, Sophia Antipolis, France. Carole Delporte-Gallet et Fabien Mathieu. Algotel 2009 11emes` Rencontres Francophones sur les Aspects Algorithmiques de Tel´ ecommunications.´ Carry-Le-Rouet, France 16-19 juin 2009. Carole Delporte-Gallet. JDIR 2009 10 th Journees´ Doctorales Informatique et Reseau.Belfort-Montb´ eliard,´ Decembre 24-25, 2009. Carole Delporte-Gallet. JDIR 2008 9 th Journees´ Doctorales Informatique et Reseau.Villeneuve´ d’Ascq, 16-18 janvier 2010. Carole Delporte-Gallet et Fabien Mathieu. JDIR 2007 8 th Journees´ Doctorales Informatique et Reseau.´ Marne-la-Vallee,´ 17-19 janvier 2010. Ca- role Delporte-Gallet. RIAMS 2007 3eme` workshop national ”Reseaux´ Biologiques : Analyse, Modelisation,´ Simulation”, La Doua, France, November 28, 2007. Nicolas Schabanel. COSI Conference´ Algerienne´ sur l’Optimisation et les Systemes` d’information, participation au comite´ de programme depuis sa creation´ en 2003, Michel Habib.

6.3.3 Organisation d’ev´ enements` scientiﬁques

6.3.3.1 Presidence´ de comites´ d’organisation

– Dagstuhl Seminar on “Epidemic Algorithms and Processes : From Theory to Applications”, Jan 21-25, 2013. Co-organisateurs : B. Doerr (MPI), R. Elsaesser (University of Paderborn), P. Frai- gniaud (CNRS and University Paris-Diderot), and R. Guerraoui (EPFL). – Dagstuhl Seminar on “Theory and Applications of Graph Searching Problems”, Feb 13-18, 2011. Co-organisateurs : F. Fomin (University of Bergen), P. Fraigniaud (CNRS and University Paris- Diderot), S. Kreutzer (TU Berlin) and D. Thilikos (University of Athens).

6.3.3.2 Participation a` des comites´ d’organisation

METRIC 2011. Trimestre interdisciplinaire mathematique´ et informatique ”Metric geometry, algorithms and groups”, Institut Henri Poincare,´ Paris, France, Janvier-Mars 2011. Nicolas Schabanel (en collaboration avec G. Kindler, J. Lee, C. Mathieu, R. O’Donnell, P. Pansu, L. Silberman). METRIC 2011 WORKSHOP 1. Int. Workshop ”Metric embeddings, algorithms and hardness of approximation”, Institut Henri Poincare,´ Paris, France, 17-21 Janvier 2011. Nicolas Schabanel (en collaboration avec G. Kindler, J. Lee, C. Mathieu, R. O’Donnell, P. Pansu, L. Silberman). METRIC 2011 WORKSHOP 2. Int. Workshop ”Expanders and Derandomization”, Institut Henri Poincare,´ Paris, France, 21-24 Mars 2011. Nicolas Schabanel (en collaboration avec G. Kindler, J. Lee, C. Mathieu, R. O’Donnell, P. Pansu, L. Silberman).

6.3.4 Participant a` des comites´ et jurys scientiﬁques

6.3.4.1 Au niveau international

FET (Future and Emerging Technologies)-OPEN en ICT (Information and Communication Technologies). Membre du comite´ d’experts (2011-present)´ : Pierre Fraigniaud. Research Grant Council de Hong Kong. Membre du comite´ d’experts (2010-present)´ : Christophe Prieur. Dijkstra Prize in Distributed Computing. President´ du jury 2011 et membre du jury 2010 : Pierre Fraigniaud. Prize for innovation in Distributed Computing. President´ du jury 2009, 2010 et 2011 : Pierre Frai- gniaud.

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6.3.4.2 Au niveau national

ANR Blanche et JCJC. Membre du comite´ d’evaluation´ pour les editions´ 2010 et 2011 : Pierre Frai- gniaud. PES CNRS 2011. Membre du jury : Pierre Fraigniaud. PES Ministere` 2012 Membre du jury : Michel Habib. Region´ Ile de France. Membre du comite´ d’evaluation´ pour les projets du Domaine d’Inter´ etˆ Majeur (DIM) Logiciel et Systemes` Complexes pour l’edition´ 2010 : Pierre Fraigniaud. IXXI. Membre elu´ du comite´ de pilotage de l’Institut Rhone-Alpinˆ des Systemes` Complexes (IXXI) depuis 2009 : Nicolas Schabanel. AERES. Membre du comite´ d’evaluation´ AERES du LIMOS, janvier 2011 : Nicolas Schabanel. Membre du comite´ d’evaluation´ du LORIA, janvier 2012 : Michel Habib

6.3.4.3 Commissions de specialistes´

– Universite´ Paris Diderot (2007-2012) : Pierre Fraigniaud. – Universite´ de Marseille – chaire CNRS (2012) : Pierre Fraigniaud. – Universite´ de Caen (2012) : Pierre Fraigniaud. – ENS Lyon (2011) : Pierre Fraigniaud (president).´ – Universite´ Pierre et Marie Curie (2011) : Pierre Fraigniaud. – Universite´ de la Mediterrann´ ee´ (2011) : Michel Habib. – Universite´ Paul Sabatie´ (2011) : Michel Habib. – Universite´ de Caen (2012) : Michel Habib (president).´ – CNAM (2012) : Michel Habib. – Universite´ de la Mediterrann´ ee´ (2011) : Nicolas Schabanel. – Universite´ Paris-Dauphine (2010) : Nicolas Trotignon. – Universite´ Grenoble 1 Joseph-Fourier (2010) : Nicolas Trotignon. – Universite´ Val-d’Essone (2010) : Nicolas Schabanel. – Universite´ de Savoie (2010) : Nicolas Schabanel. – INSA Lyon (2008) : Pierre Fraigniaud. – Universite´ de Bordeaux (2008) : Pierre Fraigniaud. – Universite´ d’Artois ( 2009 et 2010) : Yacine Boufkhad.

6.4 Activites´ de formation, encadrement et evaluation´

6.4.1 Liste des theses` et HdR soutenues

6.4.1.1 Habilitations a` diriger les recherches

– Christophe Prieur. (soutenance prevue´ a` l’automne 2012). Sujet : Reseaux´ sociaux, algorithmes, identites.´ – Nicolas Schabanel. 26 fevrier´ 2010. Sujet : Systemes` complexes & Algorithmes. – Nicolas Trotignon. 15 decembre´ 2009. Sujet : Structure des classes de graphes deﬁnies´ par l’exclusion de sous-graphes induits.

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6.4.1.2 Theses` de doctorat

Sauf mention explicite les theses` ont et´ e´ soutenu a` l’universite´ Paris Diderot. – Herve´ Baumann (soutenance septembre 2012). Sujet : Protocoles de diffusion dans les systemes` distribues´ . Allocation flech´ ee´ du ministere.` Encadrant : Pierre Fraigniaud. – Xavier Koegler (soutenance septembre 2012). Sujet : Protocoles de population. Co-encadrement avec Olivier Bournez (LIX). Allocation Moniteur Normalien. Encadrant : Pierre Fraigniaud. – Thu-Hien To. 15 decembre´ 2011. Sujet : On some graph problems in phylogenetics. Allocation Moniteur Polytechnicien. Encadrant : Michel Habib. – Mauricio Soto. 2 decembre´ 2011. Sujet :Quelques propriet´ es´ topologiques des graphes et applications a` Internet et aux reseaux´ . Encadrant : Fabien de Montgolfier et Laurent Viennot. – Djamal Belazzougui. 21 novembre 2011. Sujet : Structures compactes pour la localisation de motifs. Encadrant : Mathieu Raffinot. – Eliya Buyukkaya. 24 juin 2011. Sujet : Architecture pair-a-pair` pour le support de jeux video´ dans un environnement MANET, Bourse du projet ANR RIAM (ED P6). Actuellement Post Doct a` Tel´ ecom´ Bretagne. Encadrants : Maha Abdallah (MdC, LIP6, 90%) et Pierre Fraigniaud (10%). – Alina Stoica 12 octobre 2010. Sujet : Analyse de la structure locale des grands reseaux´ sociaux Encadrants : Christophe Prieur et Michel Habib. CIFRE avec Orange Labs, actuellement en CDI chez EDF R&D. – Thomas Hugel. 7 decembre´ 2010. Sujet : estimations de satisfaisabilite´. Encadrement :Yacine Boufkhad. – Hoang-Anh Phan. 29 septembre 2010. Sujet : Equilibrage de charge et diffusion multicast dans les systemes` pair-a-pair` , Bourse CNRS-BDI/Pays en developpement,´ actuellement Consultant en Systemes` et Reseaux´ chez Alten. Encadrant : Pierre Fraigniaud. – Andreas Tielmann. 7 mai 2010. Sujet : Minimal Conditions for Fault-Tolerant Agreement. Enca- drants : Carole Delporte et Hugues Fauconnier. – Julien Robert. 7 decembre´ 2009.Ordonnancement non-clairvoyant avec contraintes de dependances.´ (These` en informatique de l’ecole´ Normale Superieure´ de Lyon). Encadrant : Ni- colas Schabanel. – Diego Perino. 16 novembre 2009. These` CIFFRE. Sujet : Algorithmes d’allocation de ressources pour le streaming en pair-a-pair` . Encadrants : Fabien Mathieu et Laurent Viennot. – Vincent Limouzy. 3 decembre´ 2008. Sujet : Algorithmes de decomposition´ de graphes (MENRT). Encadrant : Michel Habib. – Mohssen Abboud. 27 novembre 2008. Sujet : Tolerance´ aux defaillances´ dans les reseaux´ dynamique. Encadrants : Carole Delporte et Hugues Fauconnier. – Damien Regnault. 24 novembre 2008. Sujet :Automates cellulaires probabilistes : Comportements asynchrones. (These` en informatique de l’Ecole´ Normale Superieure´ de Lyon). Encadrants : Ni- colas Schabanel et Eric Thierry.

6.4.2 Listes des rapports de theses` et d’habilitations

6.4.2.1 Rapports d’Habilitations a` Diriger les Recherches

– Laurent Massoulie´ (Technicolor, U. Paris Diderot) : Information Flows through Networks : Models and Algorithms, 20 avril 2010. Rapporteur : Pierre Fraigniaud. – David Coudert (CR INRIA, Sophia-Antipolis) : Algorithmique et optimisation dans les reseaux´ de communications, 5 mars 2010. Rapporteur : Pierre Fraigniaud.

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– Stephane´ Perennes´ (CR CNRS, I3S, Sophia-Antipolis) : Contribution a` l’algorithmique des reseaux´ de tel´ ecommunications´ , 5 mars 2010. Rapporteur : Pierre Fraigniaud. – Nicolas Schabanel (CR CNRS, LIAFA, U. Paris Diderot) : Systemes` complexes et algorithmes, 26 fevrier´ 2010. Rapporteur : Pierre Fraigniaud. – Nicolas Hanusse (CR CNRS, LaBRI, U. Bordeaux) : Navigation dans les grands graphes, 26 novembre 2010. Rapporteur : Pierre Fraigniaud. – Nicolas Trotignon ( CR CNRS LIAFA puis LIR) : Structure des classes de graphes deﬁnies´ par l’exclusion de sous-graphes induits, 15 decembre´ 2011. Rapporteur : Michel Habib. – Fabien Mathieu (France Tel´ ecom,´ HDR UPMC) : Autour du pair-a-pair` : Distribution de contenu, reseaux´ a` pref´ erences´ acycliques, 11 fev. 2009. Rapporteur : Pierre Fraigniaud. – Arnaud Legout (CR INRIA, Sophia-Antipolis) : Efﬁcacite´ et vie privee´ : de BitTorrent a` Skype, 20 janvier 2012. Rapporteur : Laurent Viennot.

6.4.2.2 Rapports de these`

– Afshin Moin, Recommendation and Visualization Techniques For Large Scale Data, 9 juillet 2012, Universite´ de Rennes. Rapporteur : Pierre Fraigniaud. – Xiaoming Wang : Deciding on the type of the agree distribution of a graph (network) from trace route-like measurements, 13 decembre´ 2011, Univ. Pierre et Marie Curie. Rapporteur : Carole Delporte. – Dorian Mazauric, Optimisation discrete` dans les reseaux´ de tel´ ecommunication´ , 7 novembre 2011, Universite´ Nice-Sophia-Antipolis. Rapporteur : Pierre Fraigniaud. – Paolo Veglia, On the network awareness of P2P-TV Applications, 23 septembre 2011, Telecom ParisTech. Rapporteur : Fabien Mathieu. – Dan-Cristian Tomozei, Distributed algorithms for peer-to-peer networks, 11 fevrier´ 2011, Univ. Pierre et Marie Curie. Rapporteur : Laurent Viennot. – Robero Costinas, Failure detections´ and communication efﬁcience in the crash and general omission failure models, 4 avril 2011, European phD, Rapporteurs : Carole Delporte (report), Hugues Fauconnier (recommendation). – Julian Monteiro, Modeling and Analysis of Reliable Peer-to-Peer Storage Systems, 16 novembre 2010, Univ. Nice Sophia-Antipolis. Rapporteur : Fabien Mathieu. – Jirˇ´ı Fink, Probabilistic Methods in Discrete Applied Mathematics, octobre 2010. Rapporteur : Jean-Sebastien´ Sereni. – Marin Bougeret, Systemes` interactifs pour la resolution´ de problemes` complexes, 15 octobre 2010, Institut National Polytechnique de Grenoble. Rapporteur : Pierre Fraigniaud. – Asim Ali : Robustness in Large Scale Distributed Systems, 8 septembre 2010, Univ. Orsay. Rap- porteur : Carole Delporte. – Rodica Mihai : Games on graphs : searching and online coloring, 15 mars 2010, University of Bergen, Norway. Rapporteur : Pierre Fraigniaud. – Gilles Tredan : Structures et systemes` repartis´ , 26 novembre 2009, Univ. Rennes. Rapporteur : Carole Delporte. – Romain Ravaux : Etudes structurelle et algorithmique de problemes` de decomposition´ de graphes : cas du probleme` de partition de graphes, 25 novembre 2009, Univ. Versailles. Rap- porteur : Pierre Fraigniaud. – Youssou Dieng : Etude structurelle des graphes et routage de plus court chemin, 23 octobre 2009, Univ. Bordeaux. Rapporteur : Pierre Fraigniaud.

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– Julien Clement´ : Algorithmique probabiliste pour systemes` distribues´ emergents´ ,19 octobre 2009, Univ. Orsay. Rapporteur : Hugues Fauconnier. – Aina Ravoaja : Mecanismes´ et architectures P2P robustes et incitatifs pour la reputation´ , 11 dec. 2008. Rapporteur : Pierre Fraigniaud. – Emanuele Fusco : Algorithmic aspects of communication tasks in networks , decembre´ 2008, Universita di Roma ”La Sapienza”. Rapporteur : Pierre Fraigniaud. – Florian Huc : Conception de reseaux´ dynamiques tolerants´ aux pannes, 14 novembre 2008, Univ. Nice -Sophia-Antipolis. Rapporteur : Pierre Fraigniaud. – Yann Busnel : Self-organized collaborative information system for large-scale wireless sensor networks : Moving theory into practice, 18 novembre 2008, Univ. Rennes. Rapporteur : Carole Delporte. – Laurent Lyaudet : Graphes et hypergraphes : complexites´ algorithmique et algebrique´ , 17 decembre´ 2007, ENS Lyon. Rapporteur : Pierre Fraigniaud. – Oskar Sandberg : The Structure and Dynamics of Navigable Networks, 14 decembre´ 07, Chalmers University, Suede.` Rapporteur : Pierre Fraigniaud. – Mathieu Liedloff : Algorithmes exacts et exponentiels pour les problemes` NP-difﬁciles : domi- nation, variantes et gen´ eralisations´ , 07 decembre´ 2007, Universite´ de Metz. Rapporteur : Pierre Fraigniaud. – Omid Amini : Algorithmique des decompositions´ de graphes Application aux reseaux´ de tel´ ecommunications´ , 28 novembre 07, Univ. Nice-Sophia-Antipolis. Rapporteur : Pierre Frai- gniaud.

6.4.3 Enseignement dispense´

6.4.3.1 Cours universitaires en M2

Les cours ”Algorithmique distribuee´ avec memoire´ partagee”,´ ”Algorithmique distribuee´ pour les reseaux”,´ ”Algorithmique des graphes” et ”Algorithmique avancee´ : Algorithmes d’approximation” du Master Parisien de Recherche en Informatique (MPRI) sont sous la responsabilites´ des membres de l’equipe´ et entierement` assures´ par les membres de l’equipe´ (sauf le cours Algorithmique avancee´ : Algorithmes d’approximation dont seulement la moitie´ est assuree´ par un membre de l’equipe)´ Les cours ”Algorithmique repartie”,´ ”Grands reseaux´ d’interaction”, ”Mobilite,´ algorithme parallele` et grilles de calcul”, ”Programmation repartie”,´ ” Protocoles des services Internet”, ”Moteurs de recherche” du Master 2 Pro Ingenierie´ Informatique de l’universite´ Paris Diderot sont assures´ par des membres de l’equipe.´ Details´ pour le MPRI : – Carole Delporte : responsable et intervenant du cours Algorithmique distribuee´ avec memoire´ partage´ –(qui remplace le cours Algorithmique repartie´ et tolerance´ aux defaillances´ ), 2007-2008 et 2009-present.´ – Pierre Fraigniaud : responsable et intervenant du cours Algorithmique distribuee´ pour les reseaux´ , 2009-present.´ – Pierre Fraigniaud : cours Algorithmique des graphes en coordination avec Michel Habib, 2007- 2009. – Hugues Fauconnier : cours Algorithmique distribuee´ avec memoire´ partage´ – ( qui remplace le cours Algorithmique repartie´ et tolerance´ aux defaillances´ ), 2007-2008 et 2009-present.´ – Michel Habib : responsable et intervenant du cours Algorithmique des graphes – 2007-present.´

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– Nicolas Schabanel : responsable et intervenant du cours Utilisations du hasard en informatique, 2010-11. – Nicolas Schabanel : responsable et intervenant du cours Algorithmique avancee´ : Algorithmes d’approximation, 2011-12. – Jean-Sebastien Sereni : cours Algorithmique des graphes, 2010-12. – Nicolas Trotignon : cours Algorithmique des graphes dans le Master Parisien de Recherche en Informatique (MPRI) – 2008-2011. – Laurent Viennot : cours reseaux´ dynamiques (MPRI) – A 2008-2009. – Laurent Viennot : cours Algorithmique distribuee´ pour les reseaux´ – 2009-present.´ Autres cours : – Carole Delporte et Hugues Fauconnier : responsables du cours Systemes` Distribues´ , Ecole Natio- nal des Ponts et Chaussees´ (2007-2008) – Pierre Fraigniaud : responsable du cours Algorithmique avancee´ , Ecole Centrale (2009-present).´ – Nicolas Schabanel : responsable du cours Algoritmo de approximacion, M2R, Universidad de Chile, Chile (2007). – Nicolas Schabanel : responsable du cours Problemes` de satisfaction de contraintes, M2R interdisciplinaire Systemes` complexes, 16h, Ecole Normale Superieure´ de Lyon (2009-12). – Fabien Mathieu : Reseaux´ Pair-a-Pair` , Master 2 Computer Science, 6h, Univ. Paris 6. – Fabien de Montgolﬁer : P2P theory and application, Univ. de Marne-la-Vallee.´ – Jean-Sebastien Sereni : Univ. Charles de Prague 2009. Graphs and Counting, cours cre´e´ et dispense´ avec M. Loebl, 9 seances.´ – Jean-Sebastien Sereni : Selecteurs´ (Alcatel) et l’arete-colorationˆ , Master Optimisation combinatoire et complexite,´ Univ. Paris I (2h). – Nicolas Trotignon : Graphes et optimisation combinatoire, Master a` l’universite´ Paris 1 (2008- 2010). – Nicolas Schabanel : Complexite´ algorithmique & Optimisation discrete` . M2R ”Mathematiques´ et applications” specialit´ e´ ”Optimisation & Theorie´ des Jeux. Modelisation´ en economie”,´ 18h, Univ. Paris 6 (2008). – Nicolas Schabanel : Le hasard en informatique et ses applications a` la modelisation´ en biologie, 3h, M2R Bio-informatique, INSA Lyon (2009). – Nicolas Schabanel : Auto-organisation de la matiere` . 6h M2R interdisciplinaire Systemes` complexes, 6h, Ecole Normale Superieure´ de Lyon (2009-11). – Nicolas Schabanel : Approche informatique des systemes` complexes, M2R Bio-informatique, 3h, INSA Lyon (2010-2012). – Nicolas Schabanel. Introduction aux graphes expandeurs. Semaine sport-etude´ du M2 informatique, 3h, Ecole Normale Superieure´ de Lyon (2012).

6.4.3.2 Jurys

– Nicolas Schabanel est membre des jurys des concours d’entree´ des ENS (2008-), de l’X (2011-) et de l’agregation´ de mathematiques´ (2011-)

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6.4.3.3 Ecoles thematiques´ et cours specialis´ es´

Organisation :

– Carole Delporte et Hugues Fauconnier : Organisation du ”Workshop on Distributed Quantum Computing” 16-19 octobre 2010, Florence, Italie. – Pierre Fraigniaud : Organisation de la 2nd DYNAMO Training School on Dynamic Networks, 4-6 juillet 2008, Reykjavik, Iceland. – Nicolas Trotignon : Organisation de ”A one-day conference on structural graph theory”, LIAFA, Paris, janvier 2011. – Christophe Prieur : Seminaire´ pluridisciplinaire Approches des reseaux´ sociaux, a` l’EHESS, depuis 2005. – Mathieu Raffinot : Co-organisation avec Benoˆıt Perthame, (Paris-6) de la journee´ de la Fed´ eration´ de mathematiques´ de Paris sur le theme` des relations entre mathematiques´ et la biologie, Paris, juin 2011. – Jean-Sebastien´ Ser´ eni´ : organisation des ”Leçons sur le lemme de regularit´ e´ ” donnees´ par Dan Kral’´ (qui a reçu le ’European prize for combinatorics’ en 2011). http://www.liafa. jussieu.fr/˜sereni/Heredia/Regularity/ (9 seances´ d’une heure trente chacune). – Jean-Sebastien´ Ser´ eni´ : co-organisation (avec L. Esperet) des ” Leçons sur les graphes epars´ ” donnees´ par P. Ossona de Mendez (cours intensif de 3 jours, 6-8 octobre 2008). – Jean-Sebastien´ Ser´ eni´ : organisation d’une serie´ de leçons sur la theorie´ extremale´ des graphes et des ordres, mai 2012.

Intervention : – Carole Delporte : Intervention dans l’ecole´ ”Ecole Internationale de Printemps Systemes` Repartis”´ (Modeles` de mobilite),´ 20-23 mai 2008, Rabat, Maroc. – Hugues Fauconnier : Intervention dans l’ecole´ ”Ecole Internationale de Printemps Systemes` Repartis”´ (Tolerance´ aux pannes), 20-23 mai 2008, Rabat, Maroc. – Pierre Fraigniaud : Intervention dans la Spring School on Algorithms, Istanbul, Turkey, 12-15 mars 2009. – Pierre Fraigniaud : Intervention dans l’ecole´ ”Emergent topics in distributed computing”, 9-14 mars 2007, La Plagne. – Michel Habib : Intervention dans la Spring School on Algorithms, Istanbul, Turkey, 12-15 mars 2009. – Michel Habib : Intervention dans le VI Escueala de Verano en Matematicas Discretas, Valparaiso, Chili, janvier 2011. – Christophe Prieur : Cours mixte sociologie / informatique en L3 Informatique a` Paris-Dauphine, avec Emmanuel Lazega, sociologue. – Nicolas Schabanel. Computing thanks to randomness. 3h. III escuela de verano en sistemas complejos, Instituto de Sistemas Complejos de Valapara´ıso (ISCV), Valpara´ıso, Chile, janvier 2007. – Nicolas Schabanel. Aplicaciones del azar a los algoritmos : de la aceleracion´ a la autocorreccion´ . 6h. III escuela de verano en matematicas´ discretas, Instituto de Sistemas Complejos de Valapara´ıso (ISCV), Valpara´ıso, Chile, janvier 2008. – Nicolas Schabanel. A computer scientist approach to complex systems. 6h, 3rd Complex System Summer School, Ecole´ normale superieure´ de Lyon, juillet 2009.

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– Nicolas Schabanel. Crash course in complexity theory. 12h (resp.), Trimestre ”Metric geometry, algorithms and groups” (METRIC 2011), Institut Henri Poincare,´ Paris, France, janvier 2011. – Nicolas Schabanel. Preuve complete` du theor´ eme` PCP. 8h, ouvert a` tous les chercheurs et organise´ a` l’ecole´ normale superieure´ de Lyon, 24-25 fevrier´ 2011. – Nicolas Schabanel. Preuve complete` du theor´ eme` PCP. 10h, ouvert a` tous les chercheurs et organise´ a` l’universite´ Paris Diderot dans le cadre d’une formation continue du CNRS, 14-16 juin 2011. – Nicolas Schabanel. Proof of the PCP theorem. 3h, 39eme` Ecole´ de Printemps d’Informatique Theorique´ (EPIT),´ Ileˆ de Re,´ France, mars 2012. – Nicolas Schabanel. Algorithmes de graphes. 6h, participation et organisation a` la formation des professeurs de lycee´ pour l’option informatique en terminales, Academie´ de Paris, 2012. – Michel Habib, Conferences´ a` l’universite´ d’et´ e´ de Mathematiques´ (Saint-Flour 2010) et Sourdun (2012) dans le cadre du plan national de formation des professeurs de lycee´ pour l’option informatique en terminales. – Jean-Sebastien´ Sereni : deux lec¸ons dans la serie´ de lec¸ons sur la theorie´ extremale´ des graphes et des ordres, mai 2012.

6.4.3.4 Vulgarisation

Participation a` la feteˆ de la Science (ateliers, conferences,´ posters) : – depuis 2008 : un atelier interactif sur Escher et la geom´ etrie´ impossible ; en 2012, atelier a` Maths en scene` (Nicolas Schabanel) – depuis 2007 : ateliers, conferences,´ posters (Christophe Prieur) – ”Strategies´ de capture de fugitifs... ou l’application de la theorie´ des graphes a` PacMan” pour presenter´ les decompositions´ de graphes (Fabien de Montgolfier) 2009. Christophe Prieur a ecrit´ plusieurs articles dans des magazines de vulgarisation (Le Monde supplement´ Sciences & Techno, Sciences & Avenir, La recherche) Laurent Viennot a et´ e´ editeur´ scientifique de )i(nterstices (http ://interstices.info), un site de vulgarisation porte´ par l’Inria, le CNRS et les universites.´ Il a publie´ deux articles dans )i(nterstices sur les reseaux´ et la difference´ entre web et internet. Laurent Viennot participe aussi au reseau´ de mediation´ scientifique de Inria pour le centre de Paris-Rocquencourt. Dans cette revue, Fabien de Montgolfier et Vincent Limouzy ont publie´ une vulgarisation sur les decomposition´ de graphes.Laurent Viennot a publie´ Idee´ reçue : Web et Internet, c’est la memeˆ chose Emmanuelle Lebhar et Nicolas Schabanel Routage dans les petits mondes.

2008 Nicolas Schabanel (resp.). Realisation´ d’une attraction ”Fenetreˆ sur l’infini” au musee´ des sciences de Santiago du Chili (cf Section 6.4.3.5). 2008 Nicolas Schabanel. Encuentra el infinito : Escher y la geometr´ıa imposible. Conference´ (45 min) grand public a` l’occasion de l’inauguration de l’attraction ”Encuentra el infinito” au musee´ des sciences de Santiago du Chili (Museo Interactivo Mirador), Chili, sept. 2010. Depuis 2008 : Nicolas Schabanel. Chaque annee,´ realisation´ d’un atelier ”Fenetreˆ sur l’infini” a` Science en Feteˆ (editions´ 2008, 2009, 2010, 2011, 2012), Universite´ Paris Diderot. 2010 Nicolas Schabanel. Escher et la spirale impossible. Conference´ (45 min) grand public dans le cadre des journees´ ”Tourbillons, spirales et labyrinthes”, Universite´ Paris Diderot, mai 2010. 2012 Nicolas Schabanel. Relations entre complexite,´ hasard et desordre´ : le regard informatique. Conference´ (45 min) grand public dans le cadre des journees´ ”Complexite/d´ esordre”,´ Universite´ Paris Diderot, juin 2012.

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2012 Nicolas Schabanel et Pierre Pansu. Couper, attendrir, trancher, reduire´ : un conte culinaire sur la resolution´ informatique des problemes` difﬁciles. A` paraˆıtre dans le journal L’explosion des mathematiques.´ 6 pages.

6.4.3.5 Transfert

Laurent Viennot a participe´ a` la creation´ de la startup Move&Play sur le partage de donnees´ personnelles. Move&Play a et´ e´ laureat´ des editions´ 2007 et 2008 du concours national OSEO d’aide a` la creation´ d’entreprises de technologies innovantes dans la categorie´ ”en emergence”´ puis ”creation-d´ eveloppement”.´ Il a accompagne´ le developpement´ de l’entreprise jusqu’en 2010, annee´ ou` l’entreprise est devenue CleverScale et a change´ de focus technique. Fabien Mathieu et Diego Perino ont depos´ e´ un brevet, ”Utilisation d’un ensemble de clients privilegi´ es´ pour une diffusion collaborative de contenu”, le 18 fevrier´ 2008 sous le N. 0851025. Les travaux de Stephane´ Raux (these` CIFRE) donnent lieu a` la mise en place d’une infrastructure d’analyse de Twitter au sein de l’entreprise Linkﬂuence, pour son cabinet d’etude´ notamment. Deux services web de visualisation lies´ a` la couverture mediatique´ de la campagne presidentielle´ ont et´ e´ realis´ es,´ – l’un laureat´ du concours Dataviz 2012 de Google France – l’autre integr´ e´ sur lemonde.fr

– Contrat de 10Ke avec le musee´ des science de Santiago du Chili (Museo Interactivo Mirador) pour le developpement´ et la realisation´ d’une attraction ”Fenetreˆ sur l’inﬁni” consistant en une transformation d’image en temps reel´ a` partir de webcam et d’appareil photo inspiree´ par un ta- bleau d’Escher. Responsable : Nicolas Schabanel, en collaboration avec Karol Suchan. Attraction inauguree´ en septembre 2008 et toujours en fonctionnement quotidien.

6.4.4 Autres

6.4.4.1 Prix et distinctions

Medaille´ d’argent du CNRS Pierre Fraigniaud est laureat´ 2012 de la Medaille´ d’argent du CNRS pour l’Institut des sciences de l’information et de leurs interactions (INS2I). Cette medaille´ distingue chaque annee´ un chercheur pour l’originalite,´ la qualite´ et l’importance de ses travaux, reconnus sur le plan national et international. Meilleur article Le prix du meilleur article a et´ e´ obtenu pour :

[DGFGT09a] Carole Delporte-Gallet, Hugues Fauconnier, Rachid Guerraoui, Andreas Tielmann. “The Disagreement Power of an Adversary.” In: Distributed Computing, 23rd International Sym- posium, DISC 2009, Elche, Spain, September 23-25, 2009. Proceedings. Vol. 5805. Lecture Notes in Computer Science. Springer, 2009, pp. 8–21 [FRT11] Pierre Fraigniaud, Sergio Rajsbaum, Corentin Travers. “Locality and Checkability in Wait- Free Computing.” In: Distributed Computing - 25th International Symposium, DISC 2011, Rome, Italy, September 20-22, 2011. Proceedings. Vol. 6950. Lecture Notes in Computer Science. Sprin- ger, 2011, pp. 333–347 [Kor09] Amos Korman. “Compact Routing Schemes for Dynamic Trees in the Fixed Port Model.” In: Distributed Computing and Networking, 10th International Conference, ICDCN 2009, Hyde- rabad, India, January 3-6, 2009. Proceedings. Vol. 5408. Lecture Notes in Computer Science. Springer, 2009, pp. 218–229

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Prix TCS En 2010, Philippe Duchon, Nicolas Hanusse, Emmanuelle Lebhar et Nicolas Schabanel ont obtenu le prix du ”TOP CITED article in TCS over 2005-2010” pour : ”Could any graph be turned into a small world ?” TCS, 355(1) :96-103, 2006.

6.4.4.2 Laboratoire europeen´ associe´

STRUCO est un laboratoire europeen´ associe´ du CNRS dont les journees´ de lancement ont eu lieu en decembre´ 2011. Son existence officielle est prevue´ pour le printemps 2012. Il regroupe le LIAFA (CNRS et l’Universite´ Paris Diderot) et IUUK (Institut d’Informatique, Universite´ Charles de Prague). Le theme` principaux du LEA sont la theorie´ des graphes, l’informatique theorique´ et la verification.´ L’un des buts de ce projet est de fournir une structure perenne´ a` de nombreuses cooperations´ entre la France et la Republique´ Tcheque` dans les domaines mentionnes.´ A` cet egard,´ l’equipe´ de recherche du LEA comprend egalement´ des chercheurs issus d’autres instituts, comme l’IHESS et l’ENS (a` Paris), le projet Mascotte (Sophia Antipolis), l’universite´ de Boheme` de l’ouest (Plzen) et celle de Brno. Le soutien du LEA se situe non seulement au niveau de la production scientifique, mais egalement´ de la dissemination´ de connaissance et de l’enseignement (ecoles,´ cours, co-tutelles de these).` Responsables : Jaroslav Nesetˇ rilˇ (CZ) et Jean-Sebastien´ Sereni (FR).

142 Part IV

Automata and Applications team

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Chapter 1

Research report: Automata and Applications

The group is composed of 19 permanent members, 7 post-doctoral researchers and 12 PhD students. Throughout this period, 6 permanent members (V. Berthe,´ L. Bienvenu, T. Colcombet, M. Gehrke, Ł. Kaiser, S. Perifel) joined the group and one left it (L. Boasson, retired in 2010). It has been reinforced in several existing topics (automata, logic algebra and games; dynamical systems; Kolmogorov complexity) and new ones have been introduced (duality theory; circuit complexity; algorithmic randomness; discrete geometry).

1.1 Research areas and main objectives

One of the challenges of computer science is to manipulate objects from an infinite set using finitary means. Of course mathematics is well accustomed to deal with infinite sets, but it is computer science that brings a completely new dimension to the picture, namely effectiveness. Most of the research of the team is related to this very general challenge: finite automata, circuits, cellular automata, discrete dynamical systems, Turing machines and many other objects studied in the group form various approaches to this problem. The historical core of the group is the study of (possibly multi-tape) finite automata and associated concepts: e.g. regularity, rationality, recognisability, sequentiality, algebraicity, syntactic semigroups, varieties, combinatorics on words and program schemes. M.-P. Schutzenberger¨ and M. Nivat are probably two prominent examples of historical members of the group that have deeply contributed to these areas. Over the years, the spectrum and the expertise of the team has expanded whilst remaining true to its heritage. Connections with verification have motivated many of these changes: new models were considered (infinite words, ordinals, finite and infinite trees), logic (monadic or temporal) had taken a central role (completing the connection with algebra and automata), more expressive machines have been considered (pushdown automata, higher-order recursion schemes), games have been proved valuable for modelling as well as for the theory of automata on infinite objects. Complexity has also been more intensively studied: whilst Kolmogorov complexity was the only subtopic studied five years ago, recent recruitments has allowed the team to develop an expertise in algorithmic randomness as well as on circuit and algebraic complexity. Finally, thanks to new members of the team discrete dynamical systems, historically present in the study of numeration systems and in the study of cellular automata, have become increasingly important in the team, leading to new applications/motivations e.g. in discrete geometry. In the following we have single out several central themes developed in the group during the last five years. It should not be seen as a partitioning of the team but rather as a division into themes that mostly interact with each other.

145 CHAPTER 1. RESEARCH REPORT: AUTOMATA AND APPLICATIONS

Recognisability

One of the central concepts that have emerged in response to this challenge is that of recognisability, whose combination with finite automata (close to the implementation of systems), logic (a sophisticated framework to specify properties of a structure) and algebra (providing essential tools available neither in logic nor in automata theory) has proved incredibly fruitful. Topology is another powerful tool. Profinite methods were used to study regular languages of words [BP09; Pin09; Pin11a; PS11] and to handle classical operations, e.g. the concatenation product [BP09; CPSE09; Pin11b] or the shuffle operation [BBCPR10; BCR08; CP12]. Extended Stone-Priestley duality, a very promising notion of recognisability has been proposed in [GGP08] and [GGP10]; duality has also been applied to domain theory, λ-calculus and program design and verification [CGR12; Geh11; GV11]. Another connection between topology, algebra and automata theory is given by the Wagner hierarchy [CD08; CD09a; CD09b; CDFM09]. There are also natural and fruitful connections with number theory, e.g. for the study of expansions with rational bases [AFS08; FK12b]. It is a challenge to extend the known results on finite words to other settings while preserving the equivalence between automata, logic and algebra. Several major results have been obtained in this direction for words indexed by linear orderings: the appropriate notions of automata, of recognisable and rational languages have been identified, their logical and algebraic properties have been thoroughly studied [BBCR08; BBCR10; BC07; BC11; BCS09; CCP11; CR07; Cri09] and specific combinatorial tools have been designed [Col10]. An equivalence between algebra and logic was also unconvered for data words [CLP11]. Regular cost functions form a quantitative extension to the theory of regular languages that preserves the milestone equivalences of regular languages. It has been studied for finite words [Col09] where algebra plays the central role and this approach allowed to characterise several natural subclasses of regular cost functions [CKL10; Kup11]. Developing regular cost functions and their applications in the tree framework required the use of games [CL08a; CL08b; CL10; KB11]. Another important line of research is the study of relations over words and their logical descriptions. Topics include multitape automata and relations on infinite alphabets [CG09a; CG09b; Cho11], relations on infinite words [Car09; Car10; CFS08], rational relations [CDV07; CDV10; CG12a; CK09; CK11b]. Regarding logic, several decision problems were solved for Presburger logic [CF07; CF10; Cho08] and the “equal last letter” predicate for words on infinite alphabets [CG09b] or tractable cases of the inclusion problem of context-free languages [BCR09; BCR11]. Expressiveness of FO[+] was also studied [CMMP10].

Games and logic

Games play a central role in automata theory and logic. Connections between imperfect information games [GS09] and tree automata were fruitfully used to define the first class of probabilistic automata on infinite trees with a decidable emptiness problem [CHS11]. The use of (stochastic) games in automata theory often relies on the existence of finite memory strategies, which constitutes an important line of research [GZ07a; GZ07b; GZ08; GZ12; Zie10]. Together with automata and logic, games are also useful for modelling and verifying complex systems. One task is to construct mathematical models of systems in which interactions between multiple players take place, in order to better understand such systems and to develop algorithms and tools to analyse them. A construction tracking information in coordination games with imperfect information was proposed, with new applications in the analysis of multi-player games with imperfect information [BKP11]. A generic method for computing evaluation functions (a key object in the understanding of games) from a specification expressed in a certain logic was introduced [KS11a]. Another task is to find descriptions of infinite state systems enjoying decidable model-checking problems: here, automata are used in the description of the system, while games permit one to solve the model-checking problem. Central

146 CHAPTER 1. RESEARCH REPORT: AUTOMATA AND APPLICATIONS contributions have been obtained in the understanding of monadic second-order logic over higher-order recursion schemes [BCHS12; BCOS10; CHMOS08; CS12; HMOS08] and in the study of automatic structures [Kai11]. Connections with regular model-checking motivate the study of partial commutations [CGP08; CM10; CP08]

Automaton Semigroups, Braids Groups

Recognisability is one deep connection between automata and (finite) semigroups. In the team we are also concerned with two completely different relations between (possibly multitape) automata and (possibly infinite) semigroups: automata are used either to generate semigroup elements (as in automaton semigroups) or to represent and multiply them (as in automatic semigroups). In both cases, the presence of automata provides a powerful combinatorial and algorithmic framework to study the semigroups. One focus of the group is on braids (interlaced strands with fixed endpoints). Braids have a natural group structure, which is known to be automatic, and they are connected to many areas in mathematics (algebra, geometry, topology) and physics. We investigated the existence of a polynomial algorithm to minimise the length (number of crossings) of a given braid. In the case of 3-strand braids, such an algorithm exists. Another related question is the rationality of the growth series enumerating braids according to their length. These series are a way to capture the combinatorial structure of the groups. The question was answered by the affirmative for positive braids [AN09], for 3-strand braids, and is open for 4-strand braids. The braid groups admit alternative automatic/Garside structures different from that first proposed by Thurston. Part of the Garside theory developed for braid groups can be applied to various other groups (generalised braid groups, torus link groups, one-relator groups with center, etc). Recent work contributed to the challenging classification of such automatic structures [CP11]. Mealy machines (i.e. a deterministic two-tape automata) can be use to describe semigroups. Indeed, such a machine defines, for each initial state, a mapping from input to output words. The collection of these mappings generates a semigroup called an automaton semigroup. This construction, formally introduced half a century ago, became very popular in group theory to build examples and counter- examples. For instance, Grigorchuk proved the existence of groups with intermediate growth using Mealy automata.We studied such semigroups with an automata-theoretic point of view and considered the classical decision problems: the word problem is decidable, the conjugacy problem is undecidable, and the finiteness problem is open. We have centred our efforts on this last problem, obtaining encour- aging preliminary results [AKLMP12]. On top of this, we worked on computational aspects improving the existing algorithms for the computation of the growth series [KMP12].

Computational Complexity, Algorithmic Randomness

Automata can also be seen as calculating machines. In the deterministic case, the relevant object is the minimal automaton: the worst-case behaviour of Hopcroft’s minimisation algorithm has been precisely analysed in [BBC09] and suprising connextions with Sturmian Trees [BBCF07; BBCF10] have been made. Minicomplexity, i.e. the study of various types of automata from a complexity point of view, has been developed in [Kap11b; Kap12a; Kap12b; KKM12] exhibiting connections with central questions on well-known complexity classes [KP12b]. Circuit complexity is another approach to computability that is developed in the group, with a special focus on circuit lower bounds. Knowing the size of circuits required to solve classes of problems is at the very heart of complexity theory since it amounts to evaluate how much resource (time, space, etc.) is needed for the problems. Both Boolean and algebraic complexity are considered. Among others, in the algebraic setting strong links between lower bounds on decision and on evaluation problems have been proved [KP09c; KP09d] as well as important results separating algebraic branching programs from formulas in the multilinear world [DMPY12]. In the Boolean setting, algorithmic randomness

147 CHAPTER 1. RESEARCH REPORT: AUTOMATA AND APPLICATIONS and derandomisation are studied and in particular their connections with resource-bounded Kolmogorov complexity. The goal of algorithmic randomness is to give a precise mathematical meaning to the notion of random object. For finite objects, this is usually achieved using the notion of Kolmogorov complexity while for infinite objects (usually real numbers), the most popular definition of randomness is the one proposed by Martin-Lof.¨ Among Martin-Lof¨ random reals, Chaitin’s Omega numbers (a particular subclass) have received tremendous attention and our team has obtained very interesting results in this direction. We gave a large class of examples of higher random reals which have a mathematical significance and we developed methods to transfer many-one completeness results of index sets to higher randomness of associated probabilities [BG07; BG09]. We have shown that Omega numbers induce a natural class of computable upper bounds for Kolmogorov complexity (called Solovay functions), and which proved to have many remarkable properties [BMN11]. Relationship between algorithmic randomness and classical analysis have been investigated showing surprising connections between Martin-Lof¨ randomness and the Lebesgue density theorem [BHMN12]. We recently initiated a study of Kolmogorov complexity from the point of view of axiomatic theories [Tav11; Tav12] and another one on the notion of randomness extraction in the setting of algorithmic randomness [BM12b]. Cellular automata are another popular model of computation that captures all features of massive parallel computing with inherent scalability issues. One focus is on algorithmic and programming considerations. We experimented around synchronisation issues [Yun08b; Yun09]. We conducted research into extracting from this program a suitable algorithm freeing the user from the physical constraints (modularity and semantics), to consider a compilation to these machines (efficient, mobile, scalable)[Yun08c] and to build an execution support system (dynamical synthesis of execution supports, sequencing, context changes) [Yun10a].

Discrete Dynamical Systems

A cellular automaton can also be seen as a discrete dynamical system, i.e. as a map acting on a set of states. In a cellular automaton the contents of all the cells evolve synchronously, each content evolving in function of the content of a few cells in its neighbourhood, according to a local rule. To take into account random events, one is led to consider probabilistic versions of cellular automata, where the local rule is randomly chosen, independently of the others, according to a distribution depending only on a finite neighbourhood of the cell. Probabilistic cellular automata appear in statistical physics and in combinatorial problems related to the enumeration of directed animals. Lastly in the context of classifying cellular automata, their robustness to random errors can be used as a discriminating factor. Major questions concerning their study are investigated in the team. Is it possible to describe explicitly the stationary measures? Is it possible to evaluate the convergence time to equilibrium? How can one sample according to the stationary measure (random generation)? See in particular [BMM11] for an efficient perfect sampling algorithm, and [BFMM12], where the density classification problem is addressed. In [CM11] a probabilistic cellular automaton on {0, 1}Z is exhibited which is non-ergodic although it has a unique invariant measure which answers in the negative an old open question. More precisely, we focus on three families of non-standard numeration systems, namely beta-numeration with Pisot bases [AFH07; AFSS10], negative bases [FL09; FL11; LS12; Ste12a] and rational bases [AFS08; FK12b]. In particular, studying expansions with rational bases or, more generally algebraic numbers that are not algebraic integers, is notoriously difficult; in [AFS08] a new and intriguing class of rational base expansions for integers and real numbers has been introduced with the set of representations of the natural integers being not a context-free language; note the deep connections with the Mahler problem on the distribution modulo 1 of the powers of 3/2. Our main tools come from automata theory, discrete mathematics, symbolic dynamics and our main application fields are cryptography [FS08; GS11], computer arithmetics [FPS11], quasicrystallography, and discrete geometry [Ber11a;

148 CHAPTER 1. RESEARCH REPORT: AUTOMATA AND APPLICATIONS

BF11; BL11a; JK12a; JK12b]. Our problems are varied and issued from number theory (transcendence issues [AF09], Diophantine approximation and continued fractions [BF11; DKS09]), as well as from symbolic dynamics (substitutive dynamical systems [BJS12], tilings and connections with fractal geometry [BSSST11; KS12]), or else from computer arithmetics. Application of proﬁnite methods to numeration was obtained in [PS08] where a noncommutative extension of Mahler’s theorem on interpolation series is presented.

1.2 Selected results of signiﬁcance

The paper [GGP08] received the best paper award in ICALP’08. Together with [GGP10] these papers propose a new notion of recognisability. They depart from the classical approach by three specific features : (1) it does not rely on automata, (2) topology, and in particular extended Stone- Priestley duality, is the key ingredient, (3) it applies to lattices of subsets rather than to individual subsets. A major consequence is that any lattice of regular languages can be defined by a set of profinite equations. See also [BP09; Pin09]. The paper [CCP11] received the best paper award in ICALP’11. It describes algebraically the expressive power of monadic second order logic over countable linear orderings. Decidability of this theory was known from the pioneer work of Rabin and Shelah but the paper provides a much more precise analysis of this logic. It has several important consequences: the first known collapse result of the logic to a specific fragment, and a natural solution to a question left open by Gurevich and Rabinovitch in 2002. It also paves the way to a theory classifying the expressiveness of fragments of monadic second-order logic over linear orderings. The paper [DMPY12] presented in STOC’12 makes a significant improvement in an important question in algebraic complexity. It concerns the power of alternative computation models such as formulas (circuits whose underlying graph is a tree) and algebraic branching programs (or ABP, directed graphs that compute a polynomial defined as the sum of the weight of all paths from a source to a sink). Whether these two restricted models are equivalent to unrestricted circuits is open. This work managed to separate ABPs from formulas in the multilinear world, thus improving the best separation from Raz between circuits and formulas.

1.3 Scientiﬁc service and inﬂuence, honors and prizes

The team and its members have a strong international visibility as demonstrated by its leadership in several international projects and collaborations. As a prominent example, let us mention the ESF Research networking programme Automata: from Mathematics to Applications (AutoMathA) which was a ﬁve-year (2005–2010) multidisciplinary programme at the crossroads of mathematics, theoretical computer science and applications. It involved 15 European countries and was chaired by J.-E.´ Pin. The handbook dedicated to combinatorics, automata, and number theory that was co-directed by V. Berthe´ [BR10a] is another example of our international visibility. Members of the groups were involved in 13 different international projects and had the (co-)leadership of 8 of them. The group is also represented in editorial boards/program committees of international journals and committee (6 different journals, and more than 50 conferences including the most prestigious ones in the area). The quality of the scientiﬁc productions of the team has been recognised by several prizes: CNRS Bronze medal awarded to T. Colcombet in 2011, ERC Starting Grant awarded to T. Colcombet in 2010, Prize and subvention of the Simone and Cina del Duca Foundation awarded by the French Academy of Science to J. Mairesse in 2009, election of J.-E.´ Pin to the Academia Europeae, and best paper awards in prestigious conferences (ICALP’08 for [GGP08], ICALP’11 for [CCP11] and Int. Conf. on Petri Nets’11 for [HMN11]). The team has also an important role on the national scale as demonstrated by the numerous participations

149 CHAPTER 1. RESEARCH REPORT: AUTOMATA AND APPLICATIONS in the scientific community and administrative responsibilities (e.g. in CNRS instances, in FSMP, in Fed´ eration´ de Recherche, in Groupements de Recherche, in learned societies), by its implication in 11 national projects and by the numerous habilitation and PhD reports written by the members of the team. On a local scale, the group is also very active in interactions with other teams from LIAFA (4 joint publications, 2 joint thesis) as well as with other groups (PPS, Mathematical Logic group & Operator Algebra group in IMJ) within the foundation Sciences Mathematiques´ de Paris . The group is involved in scientific mediation. Two of our PhD students, I. Markovici and A. Taveneaux, are members of the steering committee of Mathematic Park, a seminar for high school and undergraduate students and their teachers 1. O. Serre gave a tutorial for grandes ecoles´ computer science teachers on game theory 2. J. Mairesse was the scientific advisor for the movie Le modele` Turing produced by CNRS Images in 2012, and on the same topic he took part to the Researchers’ Film Festival 3. The group is also very active in the yearly feteˆ de la science. 1.4 Internal organization

Scientiﬁcally, the group is structured by a weekly seminar (followed by all members of the group) and several working groups (currently there are three such groups!). The PhD students are also very active in a dedicated seminar (joint with PPS). At the beginning of every year, a day is spent in welcoming the newcomers and discussing research directions. There are also frequent extemporaneous meetings with the numerous researchers visiting the group as well as with our PhD and master students. Both science and ﬁnancial policies are discussed in an horizontal manner. The selection of candidates supported by the group for permanent (university, CNRS) or temporary (invited professor, post-doc, PhD) positions is made by the whole group and always by consensus. So far the group had enough funded projects to support its activities, and, when needed, a member not being in a funded project gets support by another project in the group.

1. See http://www.ihp.fr/fr/seminaire/mathematic-park 2. See http://www.cirm.univ-mrs.fr/liste_rencontre/programmes/ProgMonasse209.pdf 3. See http://www.filmdechercheur.eu

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Fiche resum´ e:´ Automates et applications

Intitule´ de l’unite´ : LIAFA, UMR 7089 Nom du directeur de l’unite´ : Pierre Fraigniaud Nom du responsable de l’equipe´ : Olivier Serre

2.1 Effectifs

2007: 4 chercheurs CNRS, 10 enseignants-chercheurs, 3 postdoc, 8 doctorants 2012: 9 chercheurs CNRS, 10 enseignants-chercheurs, 7 postdoc, 13 doctorants Personnels qui ont quitte´ l’equipe:´ L. Boasson (retraite en septembre 2010, 44 mois), 11 doctorants (396 mois), 7 postdocs (66 mois), 2 delegation´ CNRS (32 mois). Recrutement: T. Colcombet (CR, 2007), S. Perifel (MdC, 2008), L. Bienvenu (CR, 2009), V. Berthe´ (DR, 2010), Ł. Kaiser (CR, 2010) et M. Gehrke (DR, 2011).

2.2 Production scientiﬁque

Reconnaissabilite.´ Nous avons donne´ une nouvelle notion de reconnaissabilite´ basee´ sur la dualite´ de Stone-Priestley etendue´ [GGP08; GGP10]. Nous avons introduit les fonctions reguli´ eres` de coutˆ [Col09], une extension quantitative des langages reguliers´ et organise´ un workshop autour de ces problematiques.´ Jeux et logique. Nous avons etudi´ e´ la logique MSO en particulier sur les ordres lineaires´ denombrable´ [CCP11] et sur les schemas´ recursifs´ d’ordre superieur´ [HMOS08] (sujet sur lequel nous avons organise´ un workshop). Nous avons developp´ e´ une forte expertise dans le domaine des jeux stochastiques et des jeux a` information imparfaite [GS09; GZ07a]. Semigroupes d’automates, groupes de tresses. Nous avons obtenu des resultats´ sur le probleme` difﬁ- cile de la decidabilit´ e´ de la ﬁnitude pour les semigroupes d’automates [AKLMP12]. Nous avons par ailleurs etudi´ e´ les groupes de tresses a` la fois d’un point de vue combinatoire [AN09] et du point de vue de la theorie´ de Garside [CP11]. Complexite,´ theorie´ effective de l’aleatoire.´ Nous avons renforce´ et developp´ e´ ces thematiques´ et obtenus des resultats´ importants en complexite´ algebrique´ [DMPY12], en complexite´ de Kol- mogorov [BMN11] et en theorie´ effective de l’aleatoire´ [BM12b] (sujet sur lequel nous avons organise´ un workshop). Systemes` dynamiques discrets. Nous avons etudi´ e´ les automates cellulaires probabilistes et tout particulierement` les mesures stationnaires [BMM11; CM11]. Nous avons etudi´ es´ les systemes` de numeration´ non-standard a` l’aide d’outils provenant de la theorie´ des automates, des mathematiques´ discretes` et de la dynamique symbolique, donnant des applications en cryptographie, arithmetique´ des ordinateurs et geom´ etrie´ discrete.`

151 CHAPTER 2. FICHE RESUM´ E:´ AUTOMATES ET APPLICATIONS

2.3 Bilan quantitatif

2.3.1 Publications

[GGP08] Mai Gehrke, Serge Grigorieff, Jean-Eric´ Pin. “Duality and Equational Theory of Regular Languages.” In: Proceed- ings of Automata, Languages and Programming, 35th International Colloquium (ICALP’08). Vol. 5126. Lecture Notes in Computer Science. Springer, 2008, pp. 246–257. [CCP11] Olivier Carton, Thomas Colcombet, Gabriele Puppis. “Regular Languages of Words over Countable Linear Or- derings.” In: Proceedings of Automata, Languages and Programming, 38th International Colloquium (ICALP’11). Vol. 6756. Lecture Notes in Computer Science. Springer, 2011, pp. 125–136. [DMPY12] Zeev Dvir, Guillaume Malod, Sylvain Perifel, Amir Yehudayoff. “Separating multilinear branching programs and formulas”. In: Proceedings of the 44th Annual ACM Symposium on Theory of Computing (STOC’12). To appear. ACM, 2012. [HMN11] Serge Haddad, Jean Mairesse, Hoang-Thach Nguyen. “Synthesis and Analysis of Product-Form Petri Nets.” In: Proceedings of Applications and Theory of Petri Nets, 32nd International Conference (PETRI NETS’11). Vol. 6709. Lecture Notes in Computer Science. Springer, 2011, pp. 288–307. [AFS08] Shigeki Akiyama, Christiane Frougny, Jacques Sakarovitch. “Powers of rationals modulo 1 and rational base number systems”. Israel J. Math. 168 (2008), pp. 53–91.

2.3.2 Logiciels, brevets, rapports, etc. Habilitation a` Diriger des Recherches: Jean-Baptiste Yunes,` A` propos d’automates cellulaires suivi par Des fonctions Booleennes´ , decembre´ 2007.

2.3.3 Rayonnement

1.M edaille´ de bronze du CNRS pour T. Colcombet en 2011, prix de la fondation Simone and Cina del Duca pour J. Mairesse en 2009, prix des meilleurs articles dans plusieurs conferences´ de premier plan (ICALP×2, Int. Conf. on Petri Nets). 2. T. Colcombet a rec¸u un “ERC Starting Independent Researcher Grant” en 2010. 3. J.-E.´ Pin a et´ e´ le responsable du networking programme Automata: from Mathematics to Appli- cations (AutoMathA) ﬁnance´ par la European Science Foundation (ESF). 4. Nombreuses activites´ editoriales:´ direction d’une revue, nombreuses participations a` des comite´ editoriaux/programme´ de revues et de conferences´ de premier plan. 5. Nombreuses invitations dans les conferences´ les plus importantes du domaine.

2.3.4 Interactions de l’equipe´ avec son environnement

1. Implication dans les organes decisionnaires´ de plusieurs institutions: CNRS (V. Berthe´ and J. Mairesse), FSMP (V. Berthe)´ et FR 2830 (J. Mairesse). 2. Forte implication dans le GDR Informatique Mathematique.´ 3. J. Mairesse a et´ e´ conseiller scientifique pour le film “Le modele` Turing” produit par CNRS Images en 2012, et il a participe´ au “Festival du filme de chercheur 2012”. 4. Mathematic Park: seminaire´ pour jeunes etudiants´ et lyceens;´ MATh.en.JEANS. 5. Vulgarisation: Cite´ des Sciences et de l’Industrie, College` Belgique, La Recherche.

2.3.5 Actions de formation

1. Masters (M2) de Paris Diderot: “Master Parisien de Recherche en Informatique” (4 cours). 2. Cours a` l’Ecole´ de Printemps d’Informatique Theorique´ (EPIT), a` l’Ecole´ Jeune Chercheurs en Informatique Mathematique´ (EJCIM) et a` la Spring School on Algorithmic Game Theory. 3. Enseignement aupres` de professeurs du secondaire dans le cadre de la formation au futur enseignement ISN (Informatique et Science du Numerique).´ 4. Participation recurrente´ au concours d’entree´ dans les ENS.´

152 Chapter 3

Executive Summary: Automata and Applications

Laboratory’s name: LIAFA, UMR 7089 Laboratory director’s name: Pierre Fraigniaud Team leader’s name: Olivier Serre

3.1 Members

2007: 4 CNRS researcher, 10 faculty members, 3 postdoc, 8 PhD students 2012: 9 CNRS researcher, 10 faculty members, 7 postdoc, 13 PhD students Permanent members who left the team: L. Boasson (retired since September 2010, 42 months), 11 PhD students (396 months), 7 postdocs (66 months), 2 “delegation´ CNRS” (32 months). Hiring: T. Colcombet (CR, 2007), S. Perifel (MdC, 2008), L. Bienvenu (CR, 2009), V. Berthe´ (DR, 2010), Ł. Kaiser (CR, 2010) et M. Gehrke (DR, 2011). 3.2 Scientiﬁc outcomes

Recognizability. We gave a new notion of recognizability based on extended Stone-Priestley duality [GGP08; GGP10]. We introduced regular cost functions[Col09], a qualitative extension of regular languages and we organised a workshop on this topic. Games and Logic. We studied MSO logic, in particular on countable linear ordering [CCP11] and on higher-order recursion schemes [HMOS08] (we organised on this topic a workshop). We developed a strong expertise on stochastic games and on imperfect information games [GS09; GZ07a]. Automaton Semigroups, Braids Groups We obtained results on the difﬁcult problem of deciding ﬁniteness for automaton semigroups [AKLMP12]. We also studied braids groups using combinatorial approaches [AN09] and from Garside’s theory point of view [CP11]. Computational Complexity, Algorithmic Randomness. We reinforced and developed these themes and obtained important results in algebraic complexity [DMPY12], in Kolmogorov complexity [BMN11] and in effective randomness [BM12b]. We organised a workshop on the latter. Discrete Dynamical Systems. We studied probabilistic cellular automata, in particular stationary measures [BMM11; CM11]. We studied non-standard numeration systems using tools from automata theory, discrete mathematics and symbolic dynamics, providing applications in cryptography, computer arithmetics and discrete geometry. 3.3 Quantitative assessment

3.3.1 Publications

153 CHAPTER 3. EXECUTIVE SUMMARY: AUTOMATA AND APPLICATIONS

[CCP11] Olivier Carton, Thomas Colcombet, Gabriele Puppis. “Regular Languages of Words over Countable Linear Or- derings.” In: Proceedings of Automata, Languages and Programming, 38th International Colloquium (ICALP’11). Vol. 6756. Lecture Notes in Computer Science. Springer, 2011, pp. 125–136. [DMPY12] Zeev Dvir, Guillaume Malod, Sylvain Perifel, Amir Yehudayoff. “Separating multilinear branching programs and formulas”. In: Proceedings of the 44th Annual ACM Symposium on Theory of Computing (STOC’12). To appear. ACM, 2012. [HMN11] Serge Haddad, Jean Mairesse, Hoang-Thach Nguyen. “Synthesis and Analysis of Product-Form Petri Nets.” In: Proceedings of Applications and Theory of Petri Nets, 32nd International Conference (PETRI NETS’11). Vol. 6709. Lecture Notes in Computer Science. Springer, 2011, pp. 288–307. [AFS08] Shigeki Akiyama, Christiane Frougny, Jacques Sakarovitch. “Powers of rationals modulo 1 and rational base number systems”. Israel J. Math. 168 (2008), pp. 53–91.

3.3.2 Software, patents, reports, etc. Habilitation a` Diriger des Recherches: Jean-Baptiste Yunes,` A` propos d’automates cellulaires suivi par Des fonctions Booleennes´ , decembre´ 2007.

3.3.3 Inﬂuence of the team

1. CNRS bronze medal awarded to T. Colcombet in 2011, prize and subvention of the Simone and Cina del Duca foundation awarded to J. Mairesse in 2009, best paper awards in prestigious conferences (ICALP×2, Int. Conf. on Petri Nets). 2. T. Colcombet has obtained an “ERC Starting Independent Researcher Grant” in 2010. 3. J.-E.´ Pin was the head of the ESF networking programme AutoMathA. 4. Editorial duties: Editorial board chairing of a journal, many participations to editorial boards and conferences program committees. 5. Invited talks in the most prestigious conferences.

3.3.4 Interactions between the team and its environment

1. Implication in decision making bodies of several institutions: CNRS (V. Berthe´ and J. Mairesse), FSMP (V. Berthe)´ and FR 2830 (J. Mairesse). 2. Strong implication in the GDR Informatique Mathematique.´ 3. J. Mairesse was the scientiﬁc advisor for the movie “Le modele` Turing” produced by CNRS Images in 2012, and on the same topic he took part to the “Researchers’ Film Festival”. 4. Mathematic Park: seminar for young students; MATh.en.JEANS. 5. Popularization: Cite´ des Sciences et de l’Industrie, College` Belgique, La Recherche.

3.3.5 Teaching

1. Masters (M2) from Paris Diderot: “Master Parisien de Recherche en Informatique” (4 courses). 2. Lectures at the Ecole´ de Printemps d’Informatique Theorique´ (EPIT), at the Ecole´ Jeune Chercheurs en Informatique Mathematique´ (EJCIM) and at the Spring School on Algorithmic Game Theory. 3. Lectures for high school teachers for the speciality “Informatique et Science du Numerique”.´ 4. Recurrent implication in the board of examiners for ENS.´

154 Chapter 4

Research project: Automata and Applications

4.1 Research objectives

As demonstrated in the research report, the various subtopics studied in the Automata and Applications team are intimately connected and of course these interactions will remain as the core speciﬁality of the group. In the following we identify some important challenges in the domain of expertise of the group that we plan to work on during the forthcoming years.

Frontiers of Recognisability

We propose to develop and exploit a radically new approach to the notion of recognition both within and beyond regular languages and, via a novel connection to topological duality theory, in semantic modelling. The first task is to complete the foundational work outlined in [GGP08], which covers several aspects. The fundamental observation is that, in Stone duality, the dual space of the Boolean algebra Reg of regular languages is the free profinite semigroup introduced by Reiterman. Then sublattices of Reg can be viewed as quotients of the dual algebra and thus can be defined by equations. But the idea of Stone duality is so general that it can be applied to many other settings, and in particular to infinite words, trees or data words. Advanced topology is needed: although metric spaces give the right intuition they are not sufficient to cover all cases. A further challenge would be to explore the duality beyond regular languages, but the dual spaces become much more complicated: even on a one-letter alphabet, the dual space of the set of all languages is the Stone-Cech compactification of the natural numbers, a space known as the three headed monster. The second task is to develop a battery of algebraic tools. Although there is an important existing literature on finite semigroups, the specific needs of this project require a deep understanding of the algebraic structures (semigroups, ordered semigroups, ω-semigroups, forest algebras, multi-sorted algebras, stabilisation monoids). This encompasses structure theorems involving algebraic tools like semigroup expansions, semidirect product decompositions, Mal’cev products, pointlike sets, etc. For instance, a structure theorem for forest algebras similar to the Krohn-Rhodes theorem is probably the key to the solution of the decidability of FO on trees. Another key algebraic tool is the use of syntactic invariants for deciding subclasses of languages (e.g. defined by logical fragments) For words, the Grail in this direction would be to solve the long-standing open problem of the decidability of the Σn hierarchy of FO[<], but any partial answer in this direction would be welcome. Other interesting fragments include FO[< + MOD], fragments of temporal logic or fragments occurring in database theory (words with data). Beyond regular languages, we would like to attack such problems as Straubing’s conjectures for circuit complexity classes. Relative to semantic modelling, we want to use the concept of recognition to advance various topics such as the model theory of the lambda calculus, the search for incremental coalgebraic descriptions of

155 CHAPTER 4. RESEARCH PROJECT: AUTOMATA AND APPLICATIONS algebraic logics, and the link between domain theory and algebraic logic. Our short term project is based on the ANR project FREC (Frontiers of recognisability), a joint project with LaBRI. There are other active research groups that deal with some of the topics we want to discuss. For instance, Aachen, LSV (Cachan), LIFL (Lille), Szeged and Warsaw are very well placed on the interaction between logic and automata for tree languages, including applications to verification, with also a strong algebraic flavour in Szeged and Warsaw. Boston, Brno and Porto have strong expertise on the algebraic approach for automata on words, with a tree flavour in Boston as well. Expertise on the topological aspects of automata theory can be found in Lausanne, Novosibirsk, Nijmegen and Wurzburg.¨ Aachen again, Darmstadt and Leipzig are important centers for what concerns automata with quantitative data.

Games and Logic

The relationships between games, logic and automata is a topic where the expertise of the group has been internationally recognised for more than ten years (the group was one of the eight teams involved in the EU Research and Training Network Games and Automata for Synthesis and Validation in 2002). In order to strengthen our position we will focus on three promising topics and combine them: imperfect information, multiplayer setting and quantitative aspects. Imperfect information is a standard notion in classical game theory, and is also very natural in computer science when modelling real phenomena occurring in the analysis of complex systems. Unfortunately, shifting from the perfect to the imperfect information setting strongly modifies the landscape: first, one needs to use randomised strategies; second many decidable problems become undecidable. The main task is to find tractable classes of imperfect information games by restricting the arenas and/or the winning condition/payoff function. This innovative and interdisciplinary topic is supported by a PEPS pluridisciplinary project involving computer scientists from LaBRI (Bordeaux) and mathematicians from Univ. Paris 6 and Univ. Toulouse 1. While multiplayer games are classically considered for modelling economic behaviours, our objective will be significantly different. Indeed, our motivation is the analysis of those games that arise when verifying distributed systems, or in mechanism design. Therefore, the imperfect information setting is the natural one, which leads to even more challenging problems. In particular, it is necessary to study epistemic dependencies between players. This work, initiated in [BKP11], will be done in collaboration with researchers from RWTH Aachen and LSV (Cachan). A third direction is the extension of games with quantitative measurement. In the context of qualitative verification, the games of interest are often Boolean (one player is winning, the other is loosing). However, it recently appeared that quantitative verification deserves much attention, e.g. to study the amount of resources that a system has to consume to perform a given task. This trend is reflected in the study of quantitative variants of automata, logic, and games. The thesis of L. Daviaud fits in this topic. The theory of cost functions is a particularly rich playground of this kind and is actively studied in the setting ERC starting grant GALE. In particular, the key open question in the field is the decidability of cost-monadic logic over infinite trees. It boils down to provide a correct description of the structure of winning strategies in suitable games. We also envision one more direction of study: the investigation of practical applications of finite model theory and combinatorial games. Recent results obtained in descriptive complexity theory, especially the confirmation by Grohe that LFP+C captures PTime on a large class of models, suggest that fixed-point logics with counting could indeed be used for programming. The benefits of representing a program as a logic formula are most evident if symbolic analysis of the program is necessary. For example, in [KS11a], this idea was exploited to automatically generate position evaluation functions in board games in which the winning condition is programmed by a logic formula. Another way to benefit from

156 CHAPTER 4. RESEARCH PROJECT: AUTOMATA AND APPLICATIONS representing the programs in logic is when a program is to be learned, or induced, based on a number of positive and negative examples. Using logics of different expressive power, such as first-order logic, first-order with the transitive closure operator, and also the existential and guarded fragments, allows learning to proceed from the simplest logic to the most expressive one. This technique was used in [Kai12], together with a representation of games by structure rewriting, to learn board game rules from very few example plays. These results encourage us to search for further applications of finite model theory, graph rewriting and combinatorial games in AI and other practical domains.

Inﬁnite State Systems and Veriﬁcation

Concerning infinite state systems, on top of continuing our fundamental research we plan to look for applications to verification. Our first approach will be to use tree-automatic structures to model various classes of systems (e.g. concurrent systems involving recursive procedure calls) and to look for decidable model-checking problem. This work will be done in collaboration with the Verification group, with LSV, with D. Kuske group in Ilmenau and with M. Lohrey group in Leipzig (a Procope project has been submitted) The second approach is based on higher-order recursion schemes and collapsible pushdown automata (CPDA), two equivalent formalisms to model higher-order functional programs. We started to develop a model-checker for a toy language using saturation methods for CPDA [BCHS12] and once a first proto- type is ready we will work with the Verification group to consider extension and alternative approaches (e.g. Abstraction, CEGAR. . . ). A related line of research is to develop algorithms working directly on the scheme/program which is closer to what a developer would expect. Theoretical results on CPDA games showed that one can annotate the source code with information arising from the verification. Even better, synthesis questions, involving the automatic production of a code from a partial code and a specification, can also be resolved. Whether this can be achieved in practice is a challenging problem. This line of research will be developed in collaboration with L. Ong’s group in Oxford and with A. Carayol (LIGM) and supported by various ongoing projects (ANR AMIS and two EPSRC projects). We are also convinced that it is a domain where collaboration with researchers from PPS will be successful: P.-A. Mellies` and O. Serre will co-supervise the PhD thesis of C. Grellois on this topic starting in September 2012.

Discrete Dynamical Systems

We plan to strengthen our dynamical approach of numeration systems in two directions, namely the study of the nonunit case, and second, escaping the Pisot algebraic case. The dynamical study of numeration systems with algebraic parameters relies on their self-similarity properties. Substitutions play a prominent role in this context. The term “substitution” encompasses symbolic replacement rules that act on words (generating symbolic dynamical systems), and more generally replacement rules acting on d finite sets of compact subsets of R (generating tiling spaces, the most celebrated example being the Penrose tiling). A natural generalisation of substitutive symbolic dynamical systems arises when one considers the dynamical system obtained by iterating not one, but several substitutions taken from a finite set S of substitutions: such systems are said S-adic. These systems, have hierarchical structure, but the hierarchies are not necessarily the same at each level (as it is the case for purely substitutive systems), with only finitely many different possible structures at each level. The investigation of S-adic dynamical systems yields to challenging problems. Motivations for this study are issued from discrete geometry (generation of discrete planes), Diophantine approximation (mutidimensional continued fractions and gcd computations), spectral study of symbolic dynamical systems, word combinatorics, fractal geometry, tiling theory, numeration systems, etc... An ANR project with Austria has been submitted on these topics in the prolongation of the 3 PHC programs where members of the team were involved.

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The study of equilibrium behaviour for probabilistic cellular automata (PCA) yields numerous problems. A challenging problem in this area is the positive rates conjecture, that is, the updated content of a cell can be any letter with a strictly positive probability. The positive rates conjecture states that any one-dimensional (E = Z) cellular automaton with positive rates is ergodic, i.e. has a unique and attractive invariant measure. Gacs´ exhibited in 2001 a very complex counter-example in a paper of more than 200 pages. This counter-example is far from being completely understood, and its validity is still questioned by some specialists. Even if the conjecture fails to hold, it would be important to know its domain of validity. For instance, is it true for small alphabets and neighbourhoods ? Any progress in this area would be a milestone. The positive rate conjecture is somehow linked to the classification problem detailed above. The second natural question is whether the stationary measure can be explicitly computed. Furthermore, simulating PCA is known to be a challenging task. Simulations cost a lot of time and space (especially in 2D) and configurations cannot be tracked down one by one and may only be observed through some measured parameter. Two questions are in order : what reliable deductions can we make from simulations? How can we obtain theoretical results that are meaningful for realistic sizes? A first step in this direction has been made in [BMM11]. The simulator that was developed is quite efficient in some situations. We plan to continue to develop it, and to integrate it in SAGE. The relaxation time of a PCA is defined as the expected time to reach equilibrium from its worst initial configuration. Phase transitions phenomena have been observed through simulations on some PCA. We conjecture that the polynomial/exponential phase transition for the relaxation time is deeply connected to the trivial/non-trivial invariant measures phase transition. This conjecture will be investigated by J. Mairesse and I. Marcovici in collaboration with N. Schabanel from the Distributed algorithms and graphs group.

Automaton Semigroups, Braids Groups

The 4-strand braids will receive a special attention. Indeed, while the 3-strand setting is well studied, very few is known in the 4-strand setting. In collaboration with the Combinatorics group (A. Micheli and D. Poulalhon) we are investigating the existence of a polynomial algorithm to minimise the length of a given braid. Another related question that we are investigating is the rationality of the growth series enumerating 4-strand braids according to their length. We also plan to work on the classification of the braid groups according to their automatic/Garside structures. Random walks is another topic related to braid groups. The random walker traverses the Cayley graph of the group by moving randomly to a neighbouring node at each time step. Here, thanks to automaticity of the group and the underlying automata, one can carry out explicit computations: the quantities of interest are the speed of escape to infinity of the random walker, or its entropy. Note that this approach is orthogonal to the one based on generating series and extensively studied in the 80’s and 90’s. We already carried out this program for free products of cyclic groups and for the 3-strand braid group and we aim now to consider other braid groups along the same lines. To work on these challenging topics, the group will benefit of the one-year post-doctoral stay of P. Gillib- ert (starting Sept. 2012) and of the PhD thesis of V. Juge´ (starting Sept. 2012 under the supervision of J. Mairesse). On the topic of automaton semigroups the finiteness problem still needs attention, our ultimate challenge being to prove its decidability, thus answering positively the question raised by Grigorchuk, Nekra- shevich, and Sushchanskii. On the implementation side, there exist currently two GAP packages dealing with automaton groups, one developed by Bartholdi and the other by Savchuk and Muntyan. We aim to provide implemented tools for the computation of the growth series [KMP12] that will be compatible with each of the two GAP packages.

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Computational Complexity, Algorithmic Randomness

Our research project in computational complexity follows three main directions. First, randomness is a federating theme in the group and the question that will be investigated in complexity is to what extent randomisation can speed up algorithms. This hot topic converges with a second theme, namely computing of polynomials in algebraic complexity. Indeed, one of the rare problems not yet derandomised is to test whether an arithmetic circuit evaluates to zero. The complexity of problems of this kind is well worth being studied: for instance, the test of whether the circuits evaluates to a positive value is only known to be in the counting hierarchy (a very large class) and almost no hardness result is known. Therefore better upper bounds and lower bounds have to be found. The third direction also concerns the computation of polynomials. This time, the question is how many operations are needed to compute polynomials (like the determinant or the permanent). We are thus looking for lower bounds. Since such lower bounds are very hard to prove in the general case, they are to be sought first for restricted circuits (such as multilinear or small depth circuits, formulas, branching programs, and so on). As to algorithmic randomness, there are also several directions that we are planning to pursue in the coming years. The first one concerns the line of study promoted by Miller and Nies which consists in gauging the strength of “almost sure” results in analysis. To understand what this is about, consider a theorem of classical analysis involving a co-null set of elements, in a measure-theoretic sense (for example: “a continuous non-decreasing from reals to reals, is differentiable almost everywhere”). From an algorithmic randomness viewpoint, it is interesting to look at effective versions of such theorems, where functions, sets, measures, etc, are assumed to be computable. In this setting, what we want to know is “how random” an object has to be to satisfy the theorem. In the above example, Brattka, Miller and Nies proved that a real x is computably random if and only if every computable non-decreasing function is differentiable at x. Such results are very informative and help to get better understanding of the strength of the classical theorem as well as of the corresponding randomness notion. In this line of research, we are particularly interested on effective aspects of Brownian motion, on which we are currently collaborating with the Logic group of UC Berkeley (mostly Kelty Allen, Adam Day and Theodore A. Slaman). The second one looks at algorithmic randomness (especially its finitist form, Kolmogorov complexity) from a formal logic point of view. Indeed, statements about Kolmogorov complexity can be fully for- malised in Peano Arithmetic (PA) or any theory more expressive than PA. In particular, statements of type “K(x) > n”, K denoting Kolmogorov complexity, have been shown by Chaitin in the 1960s to be independent of PA. This yields natural questions: How “useful” are such axioms? What kind of new statements can they prove? Thinking about such questions requires the simultaneous use of computability theory and model theory. This line of work is the core of Antoine Taveneaux’s PhD thesis, and is done in collaboration with Alexander Shen and Andrei Romashchenko from the LIRMM (Montpellier). The third one is the study “higher randomness” theory. Typically, algorithmic randomness looks at 0 0 effective objects that are fairly low in the arithmetic or Borel hierarchy (rarely passed Σ4 or Π4). In “higher randomness”, the basic objects of interest are instead taken to be the first levels of the analytic 1 1 hierarchy. For example, “∆1-random reals” are those which belong to no ∆1 nullsets. On the one hand, higher randomness theory requires some heavy mathematical machinery (computable ordinal theory, ramified hierarchy, forcing), but on the other hand it often gives results that are nicer than classical algorithmic randomness. Finally, let us mention that our group will be joined by two new postdoctoral students: Paul Shafer (PhD from Cornell University, USA) and Chris Porter (PhD from University of Notre Dame, USA). It is planned that they work on formalizing in type theory the “big five” constructive sub-systems of second order arithmetic (whose study is sometimes called “Reverse mathematics”).

159 CHAPTER 4. RESEARCH PROJECT: AUTOMATA AND APPLICATIONS

4.2 Project implementation

The main strengths of our group are its scientific output, its international visibility and its internal organisation. Therefore, our project will build on our strengths while reinforcing them. Our international visibility will help us to keep recruiting excellent post-doctoral researchers, and for this we will use all the tools available: European projects, ANR projects, the Foundation Sciences Mathematiques´ de Paris, local projects (region Ileˆ de France, ville de Paris). To continue attracting very good PhD students, we will be active in MPRI Master program as it is a unique forum to present the recent developments of our discipline, we will also keep co-advising doctoral thesis with colleagues from other groups in France and Europe. Thanks to our international connections and to the master programme grant with the Foundation, we expect to attract master student from abroad to continue their curriculum in our group. We will continue our implication in the national instances, in particular in GdR IM as we believe that the topics developed in the group are central ones in the much larger community of “Informatique Mathematique”.´ The main specificity of our internal activity are its numerous working groups. We believe that in the forthcoming years our weekly group seminar will be an essential tool to preserve our scientific cohesion. Indeed, while the group and its scope are getting larger, this common seminar ensures that everyone in the group gets aware of recent developments and orientations. More specialised working groups will be created when needed as we did in the last years, and these working groups will be open to a larger audience than the group itself, and probably be common sometimes with other groups from LIAFA, from PPS, from IJM or from the Paris area.

160 CHAPTER 4. RESEARCH PROJECT: AUTOMATA AND APPLICATIONS

INTERNAL

• Old-fashion perception of automata theory • by non-specialists Enlargement of the scope • may reduce unity No technology transfer

all aspects of automata • theory are covered many co-advised PhD Weakness • strong interactions with • mathematics Numerous seminars • & visitors

Strength NEGATIVE S W

• O T POSITIVE new research areas:Opportunity algorithmic randomness, • games, duality. . . interactions with other groups Threat • and disciplines postdoc + PhD hiring

Funding relies too • much on “ANR programme blanc” Reduction of the • pool of PhD students and grants

EXTERNAL

Figure 4.1: SWOT analysis of the scientiﬁc project

161 CHAPTER 4. RESEARCH PROJECT: AUTOMATA AND APPLICATIONS

162 Chapter 5

List of publications: Automata and Applications

ACL : Articles in international or national journals

Publication [CK11a] is joint with the team “Combinatoire”.

[ABPS08] Shigeki Akiyama, Horst Brunotte, Attila Petho,˝ Wolfgang Steiner. “Periodicity of certain piecewise affine planar maps”. Tsukuba J. Math. 32.1 (2008), pp. 197–251. [AF07] Petr Ambroz, Christiane Frougny. “On alpha-adic expansions in Pisot bases.” Theor. Com- put. Sci. 380.3 (2007), pp. 238–250. [AF09] Jean-Paul Allouche, Christiane Frougny. “Univoque numbers and an avatar of Thue- Morse”. Acta Arith. 136.4 (2009), pp. 319–329. [AFH07] Jean-Paul Allouche, Christiane Frougny, Kevin G. Hare. “On univoque Pisot numbers.” Math. Comput. 76.259 (2007), pp. 1639–1660. [AFS08] Shigeki Akiyama, Christiane Frougny, Jacques Sakarovitch. “Powers of rationals modulo 1 and rational base number systems”. Israel J. Math. 168 (2008), pp. 53–91. [AFSS10] Boris Adamczewski, Christiane Frougny, Anne Siegel, Wolfgang Steiner. “Rational numbers with purely periodic β-expansion”. Bull. Lond. Math. Soc. 42.3 (2010), pp. 538–552. [AKLMP12] Ali Akhavi, Ines Klimann, Sylvain Lombardy, Jean Mairesse, Matthieu Picantin. “On the finiteness problem for automaton (semi)groups”. Internat. J. Algebra Comput. (2012). To appear. [Alb09] Marie Albenque. “A note on the enumeration of directed animals via gas considerations”. Ann. Appl. Probab. 19.5 (2009), pp. 1860–1879. [ALOST11] Shigeki Akiyama, Jun Luo, Ryotaro Okazaki, Wolfgang Steiner, Jorg¨ Thuswaldner. “Similar dissection of sets”. Geom. Dedicata 150.1 (2011), pp. 233–247. [AM08] Marie Albenque, Jean-François Marckert. “Some families of increasing planar maps”. Electron. J. Probab. 13 (2008), pp. 1624–1671. [BBC09] Jean Berstel, Luc Boasson, Olivier Carton. “Continuant polynomials and worst-case behavior of Hopcroft’s minimization algorithm.” Theor. Comput. Sci. 410.30-32 (2009), pp. 2811–2822. [BBCF10] Jean Berstel, Luc Boasson, Olivier Carton, Isabelle Fagnot. “Sturmian Trees.” Theory Comput. Syst. 46.3 (2010), pp. 443–478. [BBCPR10] Jean Berstel, Luc Boasson, Olivier Carton, Jean-Eric´ Pin, Antonio Restivo. “The expressive power of the shuffle product.” Inf. Comput. 208.11 (2010), pp. 1258–1272. [BBCR10] Nicolas Bedon, Alexis Bes,` Olivier Carton, Chloe Rispal. “Logic and Rational Languages of Words Indexed by Linear Orderings.” Theory Comput. Syst. 46.4 (2010), pp. 737–760.

163 CHAPTER 5. LIST OF PUBLICATIONS: AUTOMATA AND APPLICATIONS

[BBGL11a] Alexandre Blondin Masse,´ Srecko Brlek, Ariane Garon, Sebastien´ Labbe.´ “Equations on palindromes and circular words.” Theor. Comput. Sci. 412.27 (2011), pp. 2922–2930. [BBGL11b] Alexandre Blondin Masse,´ Srecko Brlek, Ariane Garon, Sebastien´ Labbe.´ “Two infinite families of polyominoes that tile the plane by translation in two distinct ways”. Theor. Comput. Sci. 412.36 (2011), pp. 4778–4786. [BBL12] Alexandre Blondin Masse,´ Srecko Brlek, Sebastien´ Labbe.´ “A parallelogram tile fills the plane by translation in at most two distinct ways”. Discrete Applied Mathematics 160 (2012), pp. 1011–1018. [BC07]V eronique´ Bruyere,` Olivier Carton. “Automata on linear orderings.” J. Comput. Syst. Sci. 73.1 (2007), pp. 1–24. [BC08] Mikolaj Bojanczyk, Thomas Colcombet. “Tree-Walking Automata Do Not Recognize All Regular Languages.” SIAM J. Comput. 38.2 (2008), pp. 658–701. [BCR11] Alberto Bertoni, Christian Choffrut, Roberto Radicioni. “The Inclusion Problem of Context-Free Languages: Some Tractable Cases.” Int. J. Found. Comput. Sci. 22.2 (2011), pp. 289–299. [BCS09]V eronique´ Bruyere,` Olivier Carton, Geraud´ Senizergues.´ “Tree Automata and Automata on Linear Orderings.” RAIRO Theor. Inform. Appl. 43.2 (2009), pp. 321–338. [BDHMS12] Laurent Bienvenu, Adam R. Day, Mathieu Hoyrup, Ilya Mezhirov, Alexander Shen. “A constructive version of Birkhoff’s ergodic theorem for Martin-Lof¨ random points.” Inf. Comput. 210 (2012), pp. 21–30. [Ber11a] Valerie´ Berthe.´ “About thin arithmetic discrete planes.” Theor. Comput. Sci. 412.36 (2011), pp. 4757–4769. [Ber11b] Valerie´ Berthe.´ “Multidimensional Euclidean algorithms, numeration and substitutions”. Integers 11B (2011), A2, 32 pp. [Ber12] Valerie´ Berthe.´ “Numeration and discrete dynamical systems.” Computing 94.2-4 (2012), pp. 369–387. [BF11] Valerie´ Berthe,´ Thomas Fernique. “Brun expansions of stepped surfaces.” Discrete Math- ematics 311.7 (2011), pp. 521–543. [BFM07] Vasco Brattka, Christiane Frougny, Norbert Th. Muller.¨ “Foreword.” RAIRO Theor. In- form. Appl. 41.1 (2007), pp. 1–2. [BFS12] Valerie´ Berthe,´ Dirk Frettloh,¨ Victor Sirvent. “Selfdual substitutions in dimension one”. European Journal of Combinatorics 33 (2012), pp. 981–1000. [BG07] Veronica´ Becher, Serge Grigorieff. “Random reals a` la Chaitin with or without prefix- freeness.” Theor. Comput. Sci. 385.1-3 (2007), pp. 193–201. [BG09] Veronica´ Becher, Serge Grigorieff. “From index sets to randomness in EMPTY SET : random reals and possibly infinite computations. Part II.” J. Symb. Log. 74.1 (2009), pp. 124– 156. [BG11] Nick Bezhanishvili, Mai Gehrke. “Finitely generated free Heyting algebras via Birkhoff duality and coalgebra”. Logical Methods in Computer Science 7.2 (2011). [BGKR12] Dietmar Berwanger, Erich Gradel,¨ Łukasz Kaiser, Roman Rabinovich. “The Entanglement of Directed Graphs”. Theor. Comput. Sci. (2012). To appear. [BGM11] Ana Busiˇ c,´ Varun Gupta, Jean Mairesse. “Stability of the bipartite maching model”. Adv. Appl. Probab. (2011). To appear.

164 CHAPTER 5. LIST OF PUBLICATIONS: AUTOMATA AND APPLICATIONS

[BHKM12] Laurent Bienvenu, Rupert Holzl,¨ Thorsten Kraling,¨ Wolfgang Merkle. “On the separation of non-monotonic randomness notions”. Journal of Logic and Computation (2012). To appear. [Bie10] Laurent Bienvenu. “Kolmogorov-Loveland Stochasticity and Kolmogorov Complexity.” Theory Comput. Syst. 46.3 (2010), pp. 598–617. [Bie12] Laurent Bienvenu. “Strong reductions in effective randomness”. Theor. Comput. Sci. (2012). [BJS12] Valerie´ Berthe,´ Timo Jolivet, Anne Siegel. “Substitutive Arnoux-Rauzy sequences have pure discrete spectrum”. Uniform Distribution Theory 7 (2012), pp. 173–197. [BKP09] L’ubom´ıra Balkova,´ Karel Klouda, Edita Pelantova.´ “Repetitions in beta-integers”. Letters in Mathematical Physics 87 (2009), pp. 181–195. [BLPP12] Valerie´ Berthe,´ Annie Lacasse, Genevieve` Paquin, Xavier Provençal. “A study of Jacobi- Perron boundary words for the generation of discrete planes”. Theor. Comput. Sci. (2012). To appear. [BM12a] Laurent Bienvenu, Joseph S. Miller. “Randomness and lowness notions via open covers.” Ann. Pure Appl. Logic 163.5 (2012), pp. 506–518. [BMSV10] Laurent Bienvenu, Andrej Muchnik, Alexander Shen, Nikolai K. Vereshchagin. “Limit Complexities Revisited.” Theory Comput. Syst. 47.3 (2010), pp. 720–736. [BPS08] L’ubom´ıra Balkova,´ Edita Pelantova,´ Wolfgang Steiner. “Sequences with constant number of return words”. Monatsh. Math. 155.3-4 (2008), pp. 251–263. [BPS12] Adolfo Ballester-Bolinches, Jean-Eric´ Pin, Xaro Soler-Escriva.` “Formations of finite monoids and formal languages: Eilenberg’s variety theorem revisited”. Forum Mathe- maticum (2012). To appear. [BS12a] Dietmar Berwanger, Olivier Serre. “Parity Games on Undirected Graphs”. Inf. Process. Lett. (2012). To appear. [BSSST11] Valerie´ Berthe,´ Anne Siegel, Wolfgang Steiner, Paul Surer, Jorg¨ M. Thuswaldner. “Fractal tiles associated with shift radix systems”. Adv. Math. 226.1 (2011), pp. 139–175. [Car07] Olivier Carton. “The growth ratio of synchronous rational relations is unique.” Theor. Comput. Sci. 376.1-2 (2007), pp. 52–59. [CC08] Laura Chaubard, Alfredo Costa. “A new algebraic invariant for weak equivalence of sofic subshifts.” RAIRO Theor. Inform. Appl. 42.3 (2008), pp. 481–502. [CD09a] Jer´ emie´ Cabessa, Jacques Duparc. “A game theoretical approach to the algebraic counterpart of the Wagner hierarchy: Part I.” RAIRO Theor. Inform. Appl. 43.3 (2009), pp. 443– 461. [CD09b] Jer´ emie´ Cabessa, Jacques Duparc. “A Game Theoretical Approach to The Algebraic Coun- terpart of The Wagner Hierarchy: Part II.” RAIRO Theor. Inform. Appl. 43.3 (2009), pp. 463–515. [CDV07] Christian Choffrut, Flavio D’Alessandro, Stefano Varricchio. “On the separability of sparse context-free languages and of bounded rational relations.” Theor. Comput. Sci. 381.1-3 (2007), pp. 274–279. [CDV10] Christian Choffrut, Flavio D’Alessandro, Stefano Varricchio. “On Bounded Rational Trace Languages.” Theory Comput. Syst. 46.2 (2010), pp. 351–369.

165 CHAPTER 5. LIST OF PUBLICATIONS: AUTOMATA AND APPLICATIONS

[CF10] Christian Choffrut, Achille Frigeri. “Deciding whether the ordering is necessary in a Pres- burger formula.” Discrete Mathematics & Theoretical Computer Science 12.1 (2010), pp. 21–38. [CFS08] Olivier Carton, Olivier Finkel, Pierre Simonnet. “On the continuity set of an Omega rational function.” RAIRO Theor. Inform. Appl. 42.1 (2008), pp. 183–196. [CG08] Christian Choffrut, Serge Grigorieff. “The decision problem for some logics or finite words on infinite alphabets”. Zapiski Nauchnyh Seminarov POMI 258 (2008). Special volume dedicated to Yuri Matiyasevich’s 60th birthday, M.A. Vsemirnov editor, pp. 100–119. [CG09a] Christian Choffrut, Serge Grigorieff. “Finite n-tape automata over possibly infinite alphabets: Extending a theorem of Eilenberg et al.” Theor. Comput. Sci. 410.1 (2009), pp. 16– 34. [CG09b] Christian Choffrut, Serge Grigorieff. “The ”equal last letter” predicate for words on infinite alphabets and classes of multitape automata.” Theor. Comput. Sci. 410.30-32 (2009), pp. 2870–2884. [CG12a] Christian Choffrut, Serge Grigorieff. “Rational relations having a rational trace on each finite intersection of rational relations”. Theor. Comput. Sci. (2012). To appear. [CG12b] Dion Coumans, Sam van Gool. “On generalizing free algebras for a functor”. Journal of Logic and Computation (2012). To appear. [CGR12] Anna Chernilovskaya, Mai Gehrke, Lorijn Rooijen. “Generalized Kripke semantics for the Lambek–Grishin calculus”. Logic Journal of the IGLP (2012). To appear. [Cho08] Christian Choffrut. “Deciding whether a relation defined in Presburger logic can be defined in weaker logics.” RAIRO Theor. Inform. Appl. 42.1 (2008), pp. 121–135. [CK11a] Guillaume Chapuy, Ines Klimann. “On the supports of recognizable series over a field and a single letter alphabet.” Inf. Process. Lett. 111.23-24 (2011), pp. 1096–1098. [CK11b] Christian Choffrut, Juhani Karhumaki.¨ “Unique Decipherability in the Monoid of Lan- guages: An Application of Rational Relations.” Theory Comput. Syst. 49.2 (2011), pp. 355–364. [CL07] Thomas Colcombet, Christof Loding.¨ “Transforming structures by set interpretations.” Logical Methods in Computer Science 3.2 (2007). [CM10] Christian Choffrut, Robert George Mercas. “Contextual partial commutations.” Discrete Mathematics & Theoretical Computer Science 12.4 (2010), pp. 59–72. [CM11] Philippe Chassaing, Jean Mairesse. “A non-ergodic probabilistic cellular automaton with a unique invariant measure”. Stochastic Processes and their Applications 121.11 (2011), pp. 2474 –2487. [Col10] Thomas Colcombet. “Factorization forests for infinite words and applications to countable scattered linear orderings.” Theor. Comput. Sci. 411.4-5 (2010), pp. 751–764. [CP11] Ruth Corran, Matthieu Picantin. “A new Garside structure for braids groups of type (e, e, r)”. Journal of the London Mathematical Society 84.3 (2011), pp. 689–711. [CP12] Antonio Cano Gomez,´ Jean-Eric´ Pin. “Upper set monoids and length preserving mor- phisms”. J. of Pure and Applied Algebra 216 (2012), pp. 1178–1183. [CPSE09] Olivier Carton, Jean-Eric´ Pin, Xaro Soler-Escriva.` “Languages recognized by finite super- soluble groups”. Journal of Automata, Languages and Combinatorics 14 (2009), pp. 149– 161.

166 CHAPTER 5. LIST OF PUBLICATIONS: AUTOMATA AND APPLICATIONS

[CR07] Olivier Carton, Chloe Rispal. “Complementation of rational sets on scattered linear orderings of ﬁnite rank.” Theor. Comput. Sci. 382.2 (2007), pp. 109–119. [CRS08] Emilie Charlier, Michel Rigo, Wolfgang Steiner. “Abstract numeration systems on bounded languages and multiplication by a constant”. Integers 8 (2008), A35, 19 pp. (electronic). [DKS09] Karma Dajani, Cor Kraaikamp, Wolfgang Steiner. “Metrical theory for α-Rosen fractions”. J. Eur. Math. Soc. (JEMS) 11.6 (2009), pp. 1259–1283. [DTM07] Thu-Ha Dao-Thi, Jean Mairesse. “Zero-automatic queues and product form”. Adv. Appl. Probab. 39.2 (2007), pp. 429–461. [DTM08] Thu-Ha Dao-Thi, Jean Mairesse. “Zero-Automatic Networks.” Discrete Event Dynamic Systems 18.4 (2008), pp. 499–536. [EFGMS12] Chiara Epifanio, Christiane Frougny, Alessandra Gabriele, Filippo Mignosi, Jeffrey Shal- lit. “Sturmian graphs and integer representations over numeration systems.” Discrete Ap- plied Mathematics 160.4-5 (2012), pp. 536–547. [FK12a] Diana Fischer, Łukasz Kaiser. “Model Checking the Quantitative mu-Calculus on Linear Hybrid Systems”. LMCS (2012). To appear. [FK12b] Christiane Frougny, Karel Klouda. “Rational base number systems for p-adic numbers”. RAIRO Theor. Inform. Appl. 46.1 (2012), pp. 87–106. [FL11] Christiane Frougny, Anna Chiara Lai. “Negative bases and automata.” Discrete Mathemat- ics & Theoretical Computer Science 13.1 (2011), pp. 75–94. [FMP07] Christiane Frougny, Zuzana Masakov´ a,´ Edita Pelantova.´ “Inﬁnite Special Branches in Words Associated with Beta-Expansions.” Discrete Mathematics & Theoretical Computer Science 9.2 (2007). [FPS11] Christiane Frougny, Edita Pelantova,´ Milena Svobodova.´ “Parallel addition in non- standard numeration systems.” Theor. Comput. Sci. 412.41 (2011), pp. 5714–5727. [FS08] Christiane Frougny, Wolfgang Steiner. “Minimal weight expansions in Pisot bases”. J. Math. Cryptol. 2.4 (2008), pp. 365–392.

[GJP12] Mai Gehrke, Ramon Jansana, Alessandra Palmigiano. “∆1-completions of a Poset”. Order (2012). To appear. [GM08] Bruno Gaujal, Jean Mairesse. “Minimization of circuit registers: Retiming revisited.” Dis- crete Applied Mathematics 156.18 (2008), pp. 3498–3505. [Goo12] Sam van Gool. “Duality and canonical extensions for stably compact spaces”. Topology Appl. 159.1 (2012), pp. 341–359. [GP10] Marats Golovkins, Jean-Eric´ Pin. “Varieties Generated by Certain Models of Reversible Finite Automata.” Chicago J. Theor. Comput. Sci. 2010 (2010). [GS11] Peter J. Grabner, Wolfgang Steiner. “Redundancy of minimal weight expansions in Pisot bases.” Theor. Comput. Sci. 412.45 (2011), pp. 6303–6315. [GV11] Mai Gehrke, Jacob Vosmaer. “Canonical extensions and canonicity via dcpo presentations.” Theor. Comput. Sci. 412.25 (2011), pp. 2714–2723. [GV12a] Serge Grigorieff, Pierre Valarcher. “Classes of Algorithms: Formalization and Compari- son”. Bull. EATCS 107 (2012). To appear, 33 pages. [GZ12] Hugo Gimbert, Wiesław Zielonka. “Blackwell optimal strategies in priority mean-payoff games”. Int. J. Found. Comput. Sci. 23.3 (2012), pp. 687–711.

167 CHAPTER 5. LIST OF PUBLICATIONS: AUTOMATA AND APPLICATIONS

[HKT12] Michael Holtmann, Łukasz Kaiser, Wolfgang Thomas. “Degrees of Lookahead in Regular Infinite Games”. LMCS (2012). Special Issue of FoSSaCS ’10. To appear. [HMN12] Serge Haddad, Jean Mairesse, Hoang-Thach Nguyen. “Synthesis and analysis of product form Petri nets”. Fundamenta Informaticae (2012). To appear. [JK12a] Timo Jolivet, Jarkko Kari. “Consistency of multidimensional combinatorial substitutions”. Theor. Comput. Sci. (2012). To appear. [JM10] Matthieu Jonckheere, Jean Mairesse. “Towards an Erlang formula for multiclass networks.” Queueing Syst. 66.1 (2010), pp. 53–78. [Kap12b] Christos A. Kapoutsis. “Nondeterminism is essential in small two-way finite automata with few reversals”. Information and Computation (2012). To appear. [KKM12] Christos A. Kapoutsis, Richard Kralovic,´ Tobias Momke.¨ “Size complexity of rotating and sweeping automata.” J. Comput. Syst. Sci. 78.2 (2012), pp. 537–558. [KP09a] Karel Klouda, Edita Pelantova.´ “Factor complexity of infinite words associated with non- simple Parry numbers”. Integers - Electronic Journal of Combinatorial Number Theory 9 (2009), pp. 281–310. [KP09c] Pascal Koiran, Sylvain Perifel. “VPSPACE and a transfer theorem over the complex field.” Theor. Comput. Sci. 410.50 (2009), pp. 5244–5251. [KP09d] Pascal Koiran, Sylvain Perifel. “VPSPACE and a Transfer Theorem over the Reals.” Com- putational Complexity 18.4 (2009), pp. 551–575. [KP11] Pascal Koiran, Sylvain Perifel. “Interpolation in Valiant’s Theory.” Computational Com- plexity 20.1 (2011), pp. 1–20. [KS12] Charlene Kalle, Wolfgang Steiner. “Beta-expansions, natural extensions and multiple tilings associated with Pisot units”. Trans. Amer. Math. Soc. 364.5 (2012), pp. 2281–2318. [KSS12] Cor Kraaikamp, Thomas A. Schmidt, Wolfgang Steiner. “Natural extensions and entropy of α-continued fractions”. Nonlinearity 25.8 (2012), pp. 2207–2243. [LLS07] Christof Loding,¨ Carsten Lutz, Olivier Serre. “Propositional dynamic logic with recursive programs.” J. Log. Algebr. Program. 73.1-2 (2007), pp. 51–69. [LS12] Lingmin Liao, Wolfgang Steiner. “Dynamical properties of the negative beta- transformation”. Ergodic Theory Dynam. Systems (2012). To appear. [MBLV11] Alexandre Blondin Masse,´ Srecko Brlek, Sebastien´ Labbe,´ Laurent Vuillon. “Palindromic complexity of codings of rotations.” Theor. Comput. Sci. 412.46 (2011), pp. 6455–6463. [Mer08] Glenn Merlet. “Cycle time of stochastic max-plus linear systems.” Electronic Journal of Probability 13 (2008), pp. 322–340. [Mer10] Glenn Merlet. “Semigroup of matrices acting on the max-plus projective space”. Linear Algebra Appl. 432.8 (2010), pp. 1923–1935. [MM07a] Jean Mairesse, Fred´ eric´ Matheus.´ “Random Walks on Free Products of Cyclic Groups”. J. Lond. Math. Soc. 75.2 (2007), pp. 47–66. [MM07b] Jean Mairesse, Fred´ eric´ Matheus.´ “Randomly growing braid on three strands and the manta ray”. Ann. Appl. Probab. 17.2 (2007), pp. 502–536. [MMP11] Elvira Mayordomo, Philippe Moser, Sylvain Perifel. “Polylog Space Compression, Push- down Compression, and Lempel-Ziv Are Incomparable.” Theory Comput. Syst. 48.4 (2011), pp. 731–766.

168 CHAPTER 5. LIST OF PUBLICATIONS: AUTOMATA AND APPLICATIONS

[MN10] Jean Mairesse, Hoang-Thach Nguyen. “Deficiency Zero Petri Nets and Product Form.” Fundam. Inform. 105.3 (2010), pp. 237–261. [Pin12] Jean-Eric´ Pin. “Equational descriptions of languages”. Int. J. Found. Comput. Sci. (2012). To appear. [PS11] Jean-Eric´ Pin, Pedro V. Silva. “On Profinite Uniform Structures Defined by Varieties of Finite Monoids.” IJAC 21.1-2 (2011), pp. 295–314. [Ste09] Wolfgang Steiner. “Regularities of the distribution of abstract van der Corput sequences”. Unif. Distrib. Theory 4.2 (2009), pp. 81–100. [Ste12a] Wolfgang Steiner. “Digital expansions with negative real bases”. Acta Math. Hungar. (2012). To appear. [Ste12b] Wolfgang Steiner. “On the structure of (−β)-integers”. RAIRO Theor. Inform. Appl. 46.1 (2012), pp. 181–200. [Tav12] Antoine Taveneaux. “Axiomatizing Kolmogorov complexity”. Theory Comput. Syst. (2012). To appear. [UKY09a] Hiroshi Umeo, Naoki Kamikawa, Jean-Baptiste Yunes.` “A Family of Smallest Symmetri- cal Four-State Firing Squad Synchronization Protocols for Ring Arrays.” Parallel Process- ing Letters 19.2 (2009), pp. 299–313. [UKY09b] Hiroshi Umeo, Naoki Kamikawa, Jean-Baptiste Yunes.` “A family of smallest symmetri- cal four-states firing squad synchronization protocols for ring arrays”. Parallel Processing Letters 19.2 (2009), pp. 299–313. [Yun08a] Jean-Baptiste Yunes.` “A 4-states algebraic solution to linear cellular automata synchronization.” Inf. Process. Lett. 107.2 (2008), pp. 71–75. [Yun08b] Jean-Baptiste Yunes.` “An intrinsically non minimal-time Minsky-like 6-states solution to the Firing Squad synchronization problem.” RAIRO Theor. Inform. Appl. 42.1 (2008), pp. 55–68. [Yun09] Jean-Baptiste Yunes.` “Known CA Synchronizers made Insensitive to the Initial State of the Initiato.” J. Cellular Automata 4.2 (2009), pp. 147–158. [Yun12] Jean-Baptiste Yunes.` “Grids and universal computations on one-dimensional cellular automata”. Natural Computing (2012). To appear.

C-INV : Invited talks

[Ber10a] Valerie´ Berthe.´ “Muldimensional Euclid’s algorithms in discrete geometry”. Numbers, Se- quences, Lattices: Dynamical Analysis of Algorithms. Colloquium for Brigitte Vallee’s´ birthday. 2010. [Ber10b] Valerie´ Berthe.´ “Numeration and discrete dynamical systems”. International Symposium on Scientiﬁc Computing, Computer Arithmetic and Validated Numerics (SCAN 2010 GAMM - IMACS). 2010. [Col11] Thomas Colcombet. “Green’s Relations and Their Use in Automata Theory.” Proceed- ings of Language and Automata Theory and Applications, 5th International Conference (LATA’11). Vol. 6638. Lecture Notes in Computer Science. Springer, 2011, pp. 1–21. [Col12] Thomas Colcombet. “Forms of Determinism for Automata (Invited Talk).” Proceedings of 29th Annual Symposium on Theoretical Aspects of Computer Science (STACS’12). Vol. 14. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2012, pp. 1–23.

169 CHAPTER 5. LIST OF PUBLICATIONS: AUTOMATA AND APPLICATIONS

[CP08] Antonio Cano Gomez,´ Jean-Eric´ Pin. “A Robust Class of Regular Languages.” Proceed- ings of Mathematical Foundations of Computer Science, 33rd International Symposium (MFCS’08). Vol. 5162. Lecture Notes in Computer Science. Springer, 2008, pp. 36–51. [Geh11] Mai Gehrke. “Duality and Recognition.” Proceedings of Mathematical Foundations of Computer Science, 36th International Symposium (MFCS’11). Vol. 6907. Lecture Notes in Computer Science. Springer, 2011, pp. 3–18. [Kap12a] Christos A. Kapoutsis. “Minicomplexity”. Proceedings of 14th International Workshop on Descriptional Complexity of Formal Systems (DCFS’12). To appear. 2012, pp. 20–42. [Mai08] Jean Mairesse. “Random walks on algebraic structures and discrete event systems”. 3rd International Conference on Performance Evaluation Methodologies and Tools (Value- tools’08), Athenes,` Grece` . 2008. [Mai10] Jean Mairesse. “Around Probabilistic Cellular Automata”. AUTOMATA 2010, 16th intl. workshop on cellular automata & discrete complex systems, Nancy, Juin 2010. 2010. [Mai12] Jean Mairesse. “Products forms in queues, Petri nets, and probabilistic cellular automata”. Proceedings of 19th International Conference on Analytic and Stochastic Modelling Tech- niques and Applications (ASMTA’12). Lecture Notes in Computer Science. Springer, 2012. [Pin09] Jean-Eric´ Pin. “Proﬁnite Methods in Automata Theory.” Proceedings of 26th Annual Sym- posium on Theoretical Aspects of Computer Science (STACS’09). Vol. 3. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, Germany, 2009, pp. 31–50. [Pin11a] Jean-Eric´ Pin. “Equational descriptions of languages”. Proceedings of Automata and For- mal Languages, 13th International Conference (AFL’11). Invited conference, to appear in a special issue of the Int. J. Found. Comput. Sci. 2011. [Pin11b] Jean-Eric´ Pin. “Theme and Variations on the Concatenation Product”. Proceedings of Al- gebraic Informatics - 4th International Conference (CAI’11). Vol. 6742. Lecture Notes in Computer Science. Springer, 2011, pp. 44–64. [Yun10a] Jean-Baptiste Yunes.` “Achieving Universal Computations on One-Dimensional Cellular Automata.” Proceedings of 9th International Conference on Cellular Automata for Re- seach and Industry (ACRI’09). Vol. 6350. Lecture Notes in Computer Science. Springer, 2010, pp. 660–669. [Zie10] Wiesław Zielonka. “Playing in stochastic environment: from multi-armed bandits to two- player games.” Proceedings of IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FST&TCS’10). Vol. 8. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2010, pp. 65–72.

C-ACTI : International conference proceedings

Publications [CH08a; CH08b; CHMOS08] are joint with the team “Modelisation and veriﬁcation”.

[Alb07] Marie Albenque. “Bijective combinatorics of positive braids”. Proceedings of Eurocomb ’07, Electronic Notes in Discrete Mathematics 29 (2007), pp. 225–229. [ALMS08] Benjamin Aminof, Axel Legay, Aniello Murano, Olivier Serre. “µ-calculus Pushdown Module Checking with Imperfect State Information.” Proceedings of the ﬁfth IFIP In- ternational Conference On Theoretical Computer Science (IFIP TCS’08). Vol. 273. IFIP. Springer, 2008, pp. 333–348. [AN09] Marie Albenque, Philippe Nadeau. “Growth function for a class of monoids”. Proceedings of FPSAC, Discrete Math. Theor. Comput. Sci. (2009), pp. 25–38.

170 CHAPTER 5. LIST OF PUBLICATIONS: AUTOMATA AND APPLICATIONS

[BBCF07] Jean Berstel, Luc Boasson, Olivier Carton, Isabelle Fagnot. “A First Investigation of Stur- mian Trees.” Proceedings of 24th Annual Symposium on Theoretical Aspects of Com- puter Science (STACS’07). Vol. 4393. Lecture Notes in Computer Science. Springer, 2007, pp. 73–84. [BBCR08] Nicolas Bedon, Alexis Bes,` Olivier Carton, Chloe Rispal. “Logic and Rational Languages of Words Indexed by Linear Orderings.” Proceedings of the third International Computer Science Symposium in Russia (CSR’08). Vol. 5010. Lecture Notes in Computer Science. Springer, 2008, pp. 76–85. [BBGL10] Alexandre Blondin Masse,´ Srecko Brlek, Ariane Garon, Sebastien´ Labbe.´ “Every poly- omino yields at most two square tilings”. Proceedings of the 7th international conference on lattice path combinatorics and applications (Lattice’10). 5pp. 2010. [BC09] Christian W. Bach, Jer´ emie´ Cabessa. “Limit knowledge of rationality.” Proceedings of the 12th Conference on Theoretical Aspects of Rationality and Knowledge (TARK’09). 2009, pp. 34–40. [BC11] Alexis Bes,` Olivier Carton. “Algebraic Characterization of FO for Scattered Linear Order- ings.” Proceedings of Computer Science Logic, 20th Annual Conference of the EACSL (CSL’11). Vol. 12. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2011, pp. 67–81. [BCHS12] Christopher H. Broadbent, Arnaud Carayol, Matthew Hague, Olivier Serre. “A Saturation Method for Collapsible Pushdown Systems”. Proceedings of Automata, Languages and Programming, 39th International Colloquium (ICALP’12). Lecture Notes in Computer Science. To appear. Springer, 2012. [BCOS10] Christopher H. Broadbent, Arnaud Carayol, C.-H. Luke Ong, Olivier Serre. “Recursion Schemes and Logical Reflection.” Proceedings of the 25th IEEE Symposium on Logic in Computer Science (LICS’10). IEEE Computer Society, 2010, pp. 120–129. [BCR08] Alberto Bertoni, Christian Choffrut, Roberto Radicioni. “Literal Shuffle of Compressed Words.” Proceedings of the fifth IFIP International Conference On Theoretical Computer Science (IFIP TCS’08). Vol. 273. IFIP. Springer, 2008, pp. 87–100. [BCR09] Alberto Bertoni, Christian Choffrut, Roberto Radicioni. “The Inclusion Problem of Context-Free Languages: Some Tractable Cases.” Proceedings of Developments in Lan- guage Theory, 13th International Conference (DLT’09). Vol. 5583. Lecture Notes in Com- puter Science. Springer, 2009, pp. 103–112. [BDMS10] Laurent Bienvenu, Adam R. Day, Ilya Mezhirov, Alexander Shen. “Ergodic-Type Charac- terizations of Algorithmic Randomness.” Proceedings of Logic and Theory of Algorithms, 6th Conference on Computability in Europe (CiE’10). Vol. 6158. Lecture Notes in Com- puter Science. Springer, 2010, pp. 49–58. [BFMM12] A. Busiˇ c,´ N. Fates, J. Mairesse, I. Marcovici. “Density classification on infinite lattices and trees”. Proceedings of Latin American Symposium on Theoretical Informatics (LATIN’12). Vol. 7256. Lecture Notes in Computer Science. Springer, 2012, pp. 109–120. [BFRS07] Valerie´ Berthe,´ Christiane Frougny, Michel Rigo, Jacques Sakarovitch. “On the cost and complexity of the successor function”. Proceedings of the 6th International Conference Words (WORDS’07). 2007, pp. 43–56. [BGL10] Alexandre Blondin Masse,´ Ariane Garon, Sebastien´ Labbe.´ “Generation of double square tiles”. Proceedings of the 7th conference on random generation of combinatorial structures (GASCom’10). 13pp. 2010.

171 CHAPTER 5. LIST OF PUBLICATIONS: AUTOMATA AND APPLICATIONS

[BGM10] Ana Busiˇ c,´ Varun Gupta, Jean Mairesse. “Stability of the bipartite matching model.” SIG- METRICS Performance Evaluation Review 38.2 (2010), pp. 6–8. [BGMS12] Henk Barendregt, Mai Gehrke, Giulio Manzonetto, Sylvain Salvati. “Urzyczyn and Loader are Logically Related”. Proceedings of Automata, Languages and Programming, 39th International Colloquium (ICALP’12). Lecture Notes in Computer Science. To appear. Springer, 2012. [BHMN12] Laurent Bienvenu, Rupert Holzl,¨ Joseph S. Miller, Andre´ Nies. “The Denjoy alternative for computable functions.” Proceedings of 29th Annual Symposium on Theoretical Aspects of Computer Science (STACS’12). Vol. 14. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2012, pp. 543–554. [BKL12] Dietmar Berwanger, Łukasz Kaiser, Simon Lessenich. “Solving Counter Parity Games”. Proceedings of Mathematical Foundations of Computer Science, 37th International Sym- posium (MFCS’12). Lecture Notes in Computer Science. To appear. Springer, 2012. [BKP11] Dietmar Berwanger, Łukasz Kaiser, Bernd Puchala. “A Perfect-Information Construction for Coordination in Games”. Proceedings of IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FST&TCS’11). Vol. 13. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2011, pp. 387–398. [BL11a] Valerie´ Berthe,´ Sebastien´ Labbe.´ “An Arithmetic and Combinatorial Approach to Three- Dimensional Discrete Lines.” Proceedings of Discrete Geometry for Computer Imagery - 16th IAPR International Conference (DGCI’11). Vol. 6607. Lecture Notes in Computer Science. Springer, 2011, pp. 47–58. [BL11b] Valerie´ Berthe,´ Sebastien´ Labbe.´ “Uniformly balanced words with linear complexity and prescribed letter frequencies”. Proceedings of the 8th International Conference Words (WORDS’11). Vol. 63. EPTCS. 2011, pp. 44–52. [BM12b] Laurent Bienvenu, Benoit Monin. “von Neumann’s biased coin revisited”. Proceedings of the 27th IEEE Symposium on Logic in Computer Science (LICS’12). To appear. IEEE Computer Society, 2012. [BMM11] Ana Busiˇ c,´ Jean Mairesse, Irene Marcovici. “Probabilistic cellular automata, invariant measures, and perfect sampling.” Proceedings of 28th Annual Symposium on Theoreti- cal Aspects of Computer Science (STACS’11). Vol. 9. LIPIcs. Schloss Dagstuhl - Leibniz- Zentrum fuer Informatik, 2011, pp. 296–307. [BMN11] Laurent Bienvenu, Wolfgang Merkle, Andre´ Nies. “Solovay functions and K-triviality.” Proceedings of 28th Annual Symposium on Theoretical Aspects of Computer Science (STACS’11). Vol. 9. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2011, pp. 452–463. [BP09]M ario´ J. J. Branco, Jean-Eric´ Pin. “Equations Deﬁning the Polynomial Closure of a Lat- tice of Regular Languages.” Proceedings of Automata, Languages and Programming, 36th International Colloquium (ICALP’09). Vol. 5556. Lecture Notes in Computer Science. Springer, 2009, pp. 115–126. [Bro12a] Christopher H. Broadbent. “Preﬁx Rewriting for Nested-Words and Collapsible Pushdown Automata”. Proceedings of Automata, Languages and Programming, 39th International Colloquium (ICALP’12). Lecture Notes in Computer Science. To appear. Springer, 2012. [Bro12b] Christopher H. Broadbent. “The Limits of Decidability for First Order Logic on CPDA Graphs.” Proceedings of 29th Annual Symposium on Theoretical Aspects of Computer Sci- ence (STACS’12). Vol. 14. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2012, pp. 589–600.

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[BS12b] Laurent Bienvenu, Alexander Shen. “Random Semicomputable Reals Revisited.” Compu- tation, Physics and Beyond - International Workshop on Theoretical Computer Science, WTCS 2012, Dedicated to Cristian S. Calude on the Occasion of His 60th Birthday. Vol. 7160. Lecture Notes in Computer Science. Springer, 2012, pp. 31–45. [BST10b] Laurent Bienvenu, Frank Stephan, Jason Teutsch. “How Powerful Are Integer-Valued Mar- tingales?” Proceedings of Logic and Theory of Algorithms, 6th Conference on Computabil- ity in Europe (CiE’10). Vol. 6158. Lecture Notes in Computer Science. Springer, 2010, pp. 59–68. [Car09] Olivier Carton. “Left and Right Synchronous Relations.” Proceedings of Developments in Language Theory, 13th International Conference (DLT’09). Vol. 5583. Lecture Notes in Computer Science. Springer, 2009, pp. 170–182. [Car10] Olivier Carton. “Right-Sequential Functions on Infinite Words.” Proceedings of the fifth International Computer Science Symposium in Russia (CSR’10). Vol. 6072. Lecture Notes in Computer Science. Springer, 2010, pp. 96–106. [Car12] Olivier Carton. “Two-way transducers with a two-way output tape”. Proceedings of Devel- opments in Language Theory, 16th International Conference (DLT’12). Lecture Notes in Computer Science. Springer, 2012. [CCP11] Olivier Carton, Thomas Colcombet, Gabriele Puppis. “Regular Languages of Words over Countable Linear Orderings.” Proceedings of Automata, Languages and Programming, 38th International Colloquium (ICALP’11). Vol. 6756. Lecture Notes in Computer Sci- ence. Springer, 2011, pp. 125–136. [CD08] Jer´ emie´ Cabessa, Jacques Duparc. “The Algebraic Counterpart of the Wagner Hierarchy.” Proceedings of Logic and Theory of Algorithms, 4th Conference on Computability in Eu- rope (CiE’08). Vol. 5028. Lecture Notes in Computer Science. Springer, 2008, pp. 100– 109. [CDFM09] Jer´ emie´ Cabessa, Jacques Duparc, Alessandro Facchini, Filip Murlak. “The Wadge Hier- archy of Max-Regular Languages.” Proceedings of IARCS Annual Conference on Founda- tions of Software Technology and Theoretical Computer Science (FST&TCS’09). Vol. 4. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2009, pp. 121–132. [CF07] Christian Choffrut, Achille Frigeri. “Definable sets in weak Presburger arithmetic.” Pro- ceedings of Theoretical Computer Science, 10th Italian Conference (ICTCS’07). World Scientific, 2007, pp. 175–186. [CGP08] Antonio Cano Gomez,´ Giovanna Guaiana, Jean-Eric´ Pin. “When Does Partial Commuta- tive Closure Preserve Regularity?” Proceedings of Automata, Languages and Program- ming, 35th International Colloquium (ICALP’08). Vol. 5126. Lecture Notes in Computer Science. Springer, 2008, pp. 209–220. [CH08a] Julien Cristau, Florian Horn. “Graph Games on Ordinals.” Proceedings of IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FST&TCS’08). Vol. 2. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2008, pp. 143–154. [CH08b] Julien Cristau, Florian Horn. “On Reachability Games of Ordinal Length.” Proceedings of Theory and Practice of Computer Science, 34th Conference on Current Trends in Theory and Practice of Computer Science (SOFSEM’08). Vol. 4910. Lecture Notes in Computer Science. Springer, 2008, pp. 211–221.

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[CHMOS08] Arnaud Carayol, Matthew Hague, Antoine Meyer, C.-H. Luke Ong, Olivier Serre. “Win- ning Regions of Higher-Order Pushdown Games.” Proceedings of the 23rd IEEE Sympo- sium on Logic in Computer Science (LICS’08). IEEE Computer Society, 2008, pp. 193– 204. [Cho11] Christian Choffrut. “On relations of finite words over infinite alphabets.” Proceedings of Automata and Formal Languages, 13th International Conference (AFL’11). 2011, pp. 25– 27. [CHS11] Arnaud Carayol, Axel Haddad, Olivier Serre. “Qualitative Tree Languages.” Proceedings of the 26th IEEE Symposium on Logic in Computer Science (LICS’11). IEEE Computer Society, 2011, pp. 13–22. [CK09] Christian Choffrut, Juhani Karhumaki.¨ “Unique Decipherability in the Monoid of Lan- guages: An Application of Rational Relations.” Proceedings of the fourth International Computer Science Symposium in Russia (CSR’09). Vol. 5675. Lecture Notes in Computer Science. Springer, 2009, pp. 71–79. [CKL10] Thomas Colcombet, Denis Kuperberg, Sylvain Lombardy. “Regular Temporal Cost Func- tions.” Proceedings of Automata, Languages and Programming, 37th International Col- loquium (ICALP’10). Vol. 6199. Lecture Notes in Computer Science. Springer, 2010, pp. 563–574. [CL08a] Thomas Colcombet, Christof Loding.¨ “The Nesting-Depth of Disjunctive µ-Calculus for Tree Languages and the Limitedness Problem.” Proceedings of Computer Science Logic, 17th Annual Conference of the EACSL (CSL’08). Vol. 5213. Lecture Notes in Computer Science. Springer, 2008, pp. 416–430. [CL08b] Thomas Colcombet, Christof Loding.¨ “The Non-deterministic Mostowski Hierarchy and Distance-Parity Automata.” Proceedings of Automata, Languages and Programming, 35th International Colloquium (ICALP’08). Vol. 5126. Lecture Notes in Computer Science. Springer, 2008, pp. 398–409. [CL10] Thomas Colcombet, Christof Loding.¨ “Regular Cost Functions over Finite Trees.” Pro- ceedings of the 25th IEEE Symposium on Logic in Computer Science (LICS’10). IEEE Computer Society, 2010, pp. 70–79. [CLP11] Thomas Colcombet, Clemens Ley, Gabriele Puppis. “On the Use of Guards for Logics with Data.” Proceedings of Mathematical Foundations of Computer Science, 36th International Symposium (MFCS’11). Vol. 6907. Lecture Notes in Computer Science. Springer, 2011, pp. 243–255. [CMMP10] Christian Choffrut, Andreas Malcher, Carlo Mereghetti, Beatrice Palano. “On the Expres- sive Power of FO[ + ].” Proceedings of Language and Automata Theory and Applications, 4th International Conference (LATA’10). Vol. 6031. Lecture Notes in Computer Science. Springer, 2010, pp. 190–201. [Col07a] Thomas Colcombet. “A Combinatorial Theorem for Trees.” Proceedings of Automata, Languages and Programming, 34th International Colloquium (ICALP’07). Vol. 4596. Lec- ture Notes in Computer Science. Springer, 2007, pp. 901–912. [Col07b] Thomas Colcombet. “Factorisation Forests for Infinite Words.” Proceedings of Fundamen- tals of Computation Theory, 16th International Symposium (FCT’07). Vol. 4639. Lecture Notes in Computer Science. Springer, 2007, pp. 226–237. [Col09] Thomas Colcombet. “The Theory of Stabilisation Monoids and Regular Cost Functions.” Proceedings of Automata, Languages and Programming, 36th International Colloquium (ICALP’09). Vol. 5556. Lecture Notes in Computer Science. Springer, 2009, pp. 139–150.

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[CP07] Laura Chaubard, Jean-Eric´ Pin. “Open problems on regular languages: an historical perspective”. Proceedings of Semigroups and formal languages. Word Scientiﬁc, 2007, pp. 39–56. [Cri09] Julien Cristau. “Automata and temporal logic over arbitrary linear time.” Proceedings of IARCS Annual Conference on Foundations of Software Technology and Theoretical Com- puter Science (FST&TCS’09). Vol. 4. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2009, pp. 133–144. [CS12] Arnaud Carayol, Olivier Serre. “Collapsible Pushdown Automata and Labeled Recursion Schemes: Equivalence, Safety and Effective Selection”. Proceedings of the 27th IEEE Symposium on Logic in Computer Science (LICS’12). To appear. IEEE Computer Soci- ety, 2012. [CZ09] Thomas Colcombet, Konrad Zdanowski. “A Tight Lower Bound for Determinization of Transition Labeled Buchi¨ Automata.” Proceedings of Automata, Languages and Program- ming, 36th International Colloquium (ICALP’09). Vol. 5556. Lecture Notes in Computer Science. Springer, 2009, pp. 151–162. [DMPY12] Zeev Dvir, Guillaume Malod, Sylvain Perifel, Amir Yehudayoff. “Separating multilinear branching programs and formulas”. Proceedings of the 44th Annual ACM Symposium on Theory of Computing (STOC’12). To appear. ACM, 2012. [EFGMS10] Chiara Epifanio, Christiane Frougny, Alessandra Gabriele, Filippo Mignosi, Jeffrey Shal- lit. “On Lazy Representations and Sturmian Graphs.” Proceedings of Implementation and Application of Automata - 15th International Conference (CIAA’10). Vol. 6482. Lecture Notes in Computer Science 7381. Springer, 2010, pp. 125–134. [FIMY11] Enrico Formenti, Katsunobu Imai, Bruno Martin, Jean-Baptiste Yunes.` “A Boolean approach to cellular automata random sequences generation.” Proceedings of 17th Interna- tional Workshop on Cellular Automata and Discrete Complex Systems (Automata 2011). 2011. [FK11] Diana Fischer, Łukasz Kaiser. “Model Checking the Quantitative µ-Calculus on Linear Hybrid Systems”. Proceedings of Automata, Languages and Programming, 38th Interna- tional Colloquium (ICALP’11). Vol. 6756. Lecture Notes in Computer Science. Springer, 2011, pp. 404–415. [FL09] Christiane Frougny, Anna Chiara Lai. “On Negative Bases.” Proceedings of Developments in Language Theory, 13th International Conference (DLT’09). Vol. 5583. Lecture Notes in Computer Science. Springer, 2009, pp. 252–263. [Fri09] Achille Frigeri. “Automata and Logic on p-adic numbers.” Proceedings of Theoretical Computer Science, 11th Italian Conference (ICTCS’09). 2009, pp. 117–120. [FZG10] Marie Ferbus-Zanda, Serge Grigorieff. “ASMs and Operational Algorithmic Complete- ness of Lambda Calculus.” Fields of Logic and Computation, Essays Dedicated to Yuri Gurevich on the Occasion of His 70th Birthday. Vol. 6300. Lecture Notes in Computer Science. Springer, 2010, pp. 301–327. [GGP08] Mai Gehrke, Serge Grigorieff, Jean-Eric´ Pin. “Duality and Equational Theory of Regular Languages.” Proceedings of Automata, Languages and Programming, 35th International Colloquium (ICALP’08). Vol. 5126. Lecture Notes in Computer Science. Springer, 2008, pp. 246–257. [GGP10] Mai Gehrke, Serge Grigorieff, Jean-Eric´ Pin. “A Topological Approach to Recognition.” Proceedings of Automata, Languages and Programming, 37th International Colloquium (ICALP’10). Vol. 6199. Lecture Notes in Computer Science. Springer, 2010, pp. 151–162.

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[GHM08] Rob M.P. Goverde, Bernd Heidergott, Glenn Merlet. “A fast approximation algorithm for the Lyapunov exponent of stochastic max-plus systems”. Proceedings of the International Workshop on Discrete Event Systems (WODES’08). 2008, pp. 49–54. [GMSZ08] Blaise Genest, Anca Muscholl, Olivier Serre, Marc Zeitoun. “Tree Pattern Rewriting Sys- tems.” Proceedings of Automated Technology for Verification and Analysis, 6th Interna- tional Symposium (ATVA’08). Vol. 5311. Lecture Notes in Computer Science. Springer, 2008, pp. 332–346. [GS09] Vincent Gripon, Olivier Serre. “Qualitative Concurrent Stochastic Games with Imperfect Information.” Proceedings of Automata, Languages and Programming, 36th International Colloquium (ICALP’09). Vol. 5556. Lecture Notes in Computer Science. Springer, 2009, pp. 200–211. [GV10] Serge Grigorieff, Pierre Valarcher. “Evolving Multialgebras Unify All Usual Sequential Computation Models.” Proceedings of 27th Annual Symposium on Theoretical Aspects of Computer Science (STACS’10). Vol. 5. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2010, pp. 417–428. [GV12b] Serge Grigorieff, Pierre Valarcher. “Functionals using Bounded Information and the Dy- namics of Algorithms”. Proceedings of the 27th IEEE Symposium on Logic in Computer Science (LICS’12). To appear. IEEE Computer Society, 2012. [GZ07a] Hugo Gimbert, Wiesław Zielonka. “Limits of Multi-Discounted Markov Decision Pro- cesses.” Proceedings of the 22nd IEEE Symposium on Logic in Computer Science (LICS’07). IEEE Computer Society, 2007, pp. 89–98. [GZ07b] Hugo Gimbert, Wiesław Zielonka. “Perfect Information Stochastic Priority Games.” Pro- ceedings of Automata, Languages and Programming, 34th International Colloquium (ICALP’07). Vol. 4596. Lecture Notes in Computer Science. Springer, 2007, pp. 850–861. [GZ10] Hugo Gimbert, Wiesław Zielonka. “Blackwell-Optimal Strategies in Priority Mean-Payoff Games”. Proceedings of 1st International Symposium on Games, Automata, Logics and Formal Verification (GandALF 2010). Vol. 25. EPTCS. 2010, pp. 7–21. [Had12] Axel Haddad. “IO vs OI in Higher-Order Recursion Schemes”. Proceedings of the 8th Workshop on Fixed Points in Computer Science (FICS 2012). Vol. 77. EPTCS. 2012, pp. 23–30. [Hag11] Matthew Hague. “Parameterised Pushdown Systems with Non-Atomic Writes.” Proceed- ings of IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FST&TCS’11). Vol. 13. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2011, pp. 457–468. [HL11] Matthew Hague, Anthony Widjaja Lin. “Model Checking Recursive Programs with Nu- meric Data Types.” Proceedings of Computer Aided Verification - 23rd International Con- ference (CAV’11). Vol. 6806. Lecture Notes in Computer Science. Springer, 2011, pp. 743– 759. [HMN11] Serge Haddad, Jean Mairesse, Hoang-Thach Nguyen. “Synthesis and Analysis of Product- Form Petri Nets.” Proceedings of Applications and Theory of Petri Nets, 32nd Interna- tional Conference (PETRI NETS’11). Vol. 6709. Lecture Notes in Computer Science. Springer, 2011, pp. 288–307. [HMOS08] Matthew Hague, Andrzej S. Murawski, C.-H. Luke Ong, Olivier Serre. “Collapsible Push- down Automata and Recursion Schemes.” Proceedings of the 23rd IEEE Symposium on Logic in Computer Science (LICS’08). IEEE Computer Society, 2008, pp. 452–461.

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[JK12b] Timo Jolivet, Jarkko Kari. “Consistency of multidimensional combinatorial substitutions”. Proceedings of the seventh International Computer Science Symposium in Russia (CSR’12). Lecture Notes in Computer Science. To appear. Springer, 2012. [Kai12] Łukasz Kaiser. “Learning Games from Videos Guided by Descriptive Complexity”. Pro- ceedings of the Twenty-Sixth AAAI Conference on Artificial Intelligence (AAAI’12). To appear. AAAI Press, 2012. [Kap11a] Christos A. Kapoutsis. “Nondeterminism is essential in small 2FAs with few reversals”. Proceedings of Automata, Languages and Programming, 38th International Colloquium (ICALP’11). Vol. 6756. Lecture Notes in Computer Science. Springer, 2011, pp. 192–209. [Kap11b] Christos A. Kapoutsis. “Two-way automata versus logarithmic space”. Proceedings of the sixth International Computer Science Symposium in Russia (CSR’11). Vol. 6651. Lecture Notes in Computer Science. Springer, 2011, pp. 359–372. [KB11] Denis Kuperberg, Michael Vanden Boom. “Quasi-Weak Cost Automata: A New Variant of Weakness.” Proceedings of IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FST&TCS’11). Vol. 13. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2011, pp. 66–77. [KB12] Denis Kuperberg, Michael Vanden Boom. “On the Expressive Power of Cost Logics over Infinite Words”. Proceedings of Automata, Languages and Programming, 39th Interna- tional Colloquium (ICALP’12). Lecture Notes in Computer Science. To appear. Springer, 2012. [KHTT12] Bjørn Kjos-Hanssen, Antoine Taveneaux, Neil Thapen. “How much randomness is needed for statistics?” Proceedings of Logic and Theory of Algorithms, 8th Conference on Com- putability in Europe (CiE’12). Lecture Notes in Computer Science. To appear. Springer, 2012. [KL12] Christos A. Kapoutsis, Nans Levebvre. “Analogs of Fagin’s Theorem for small nondeterministic finite automata”. Proceedings of Developments in Language Theory, 16th Interna- tional Conference (DLT’12). Lecture Notes in Computer Science. Springer, 2012, pp. 202– 213. [KMP12] Ines Klimann, Jean Mairesse, Matthieu Picantin. “Implementing computations in automaton (semi)groups”. Proceedings of Implementation and Applications of Automata, 17th International Conference (CIAA 2012). Vol. 7381. Lecture Notes in Computer Science. Springer, 2012, pp. 240–252. [KP09b] Pascal Koiran, Sylvain Perifel. “A Superpolynomial Lower Bound on the Size of Uniform Non-constant-depth Threshold Circuits for the Permanent.” Proceedings of the 24th An- nual IEEE Conference on Computational Complexity (CCC’09). IEEE Computer Society, 2009, pp. 35–40. [KP12a] Christos A. Kapoutsis, Giovanni Pighizzini. “Reversal hierarchies for small 2DFAs”. Pro- ceedings of Mathematical Foundations of Computer Science, 37th International Sympo- sium (MFCS’12). Lecture Notes in Computer Science. To appear. Springer, 2012. [KP12b] Christos A. Kapoutsis, Giovanni Pighizzini. “Two-way automata characterizations of L/poly versus NL”. Proceedings of the seventh International Computer Science Sympo- sium in Russia (CSR’12). Lecture Notes in Computer Science. To appear. Springer, 2012, pp. 222–233. [KS11a] Łukasz Kaiser, Łukasz Stafiniak. “First-Order Logic with Counting for General Game Playing”. Proceedings of the Twenty-Fifth AAAI Conference on Artificial Intelligence (AAAI’11). AAAI Press, 2011, pp. 791–796.

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[KS11b] Łukasz Kaiser, Łukasz Stafiniak. “Translating the Game Description Langauge to Toss”. Proceedings of the 2nd International General Game Playing Workshop (GIGA’11). 2011, pp. 91–98. [Kup11] Denis Kuperberg. “Linear temporal logic for regular cost functions.” Proceedings of 28th Annual Symposium on Theoretical Aspects of Computer Science (STACS’11). Vol. 9. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2011, pp. 627–636. [MN09] Jean Mairesse, Hoang-Thach Nguyen. “Deficiency Zero Petri Nets and Product Form.” Proceedings of Applications and Theory of Petri Nets, 30th International Conference (PETRI NETS’09). Vol. 5606. Lecture Notes in Computer Science. Springer, 2009, pp. 103–122. [MY12] Luidnel Maignan, Jean-Baptiste Yunes.` “A Spatio-Temporal Algorithmic Point of View on Firing Squad Synchronisation Problem”. Proceeding of Cellular Automata - 10th Interna- tional Conference on Cellular Automata for Research and Industry (ACRI 2012). Lecture Notes in Computer Science. To appear. Springer, 2012. [PS08] Jean-Eric´ Pin, Pedro V. Silva. “A Mahler’s theorem for functions from words to integers.” Proceedings of 25th Annual Symposium on Theoretical Aspects of Computer Sci- ence (STACS’08). Vol. 1. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, Germany, 2008, pp. 585–596. [Ste11] Wolfgang Steiner. “On the Delone property of (−β)-integers”. Proceedings of the 8th In- ternational Conference Words (WORDS’11). Vol. 63. EPTCS. 2011, pp. 247–256. [Tav11] Antoine Taveneaux. “Towards an Axiomatic System for Kolmogorov Complexity.” Pro- ceedings of Logic and Theory of Algorithms, 7th Conference on Computability in Europe (CiE’11). Vol. 6735. Lecture Notes in Computer Science. Springer, 2011, pp. 280–289. [UKY08] Hiroshi Umeo, Naoki Kamikawa, Jean-Baptiste Yunes.` “A family of smallest symmetri- cal four-state firing squad synchronization protocols for one-dimensional ring cellular automata.” Proceedings of Automata 2008: Theory and Applications of Cellular Automata. Luniver Press, Frome, UK, 2008, pp. 174–186. [UKY09c] Hiroshi Umeo, Naoki Kamikawa, Jean-Baptiste Yunes.` “A Two-Dimensional Optimum- Time Firing Squad Synchronization Algorithm and Its Implementation”. Proceedings of the International Workshop on Natural Computing (IWNC’09). Information and Commu- nications Technology 2. 2009, pp. 342–351. [UYK08] Hiroshi Umeo, Jean-Baptiste Yunes,` Naoki Kamikawa. “About 4-States Solutions to the Firing Squad Synchronization Problem.” Proceedings of 8th International Conference on Cellular Automata for Reseach and Industry (ACRI’08). Vol. 5191. Lecture Notes in Com- puter Science. Springer, 2008, pp. 108–113. [Yun07] Jean-Baptiste Yunes.` “Simple New Algorithms Which Solve the Firing Squad Synchro- nization Problem: A 7-States 4-Steps Solution.” Proceedings of Machines, Computations, and Universality, 5th International Conference (MCU’07). Vol. 4664. Lecture Notes in Computer Science. Springer, 2007, pp. 316–324. [Yun08c] Jean-Baptiste Yunes.` “Goto’s construction and Pascal’s triangle: new insights into cellular automata synchronization.” Proceedings of the First Symposium on Cellular Automata ”Journees´ Automates Cellulaires” (JAC’08). MCCME Publishing House, Moscow, 2008, pp. 195–203.

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[Yun10b] Jean-Baptiste Yunes.` “Achieving Universal Computations on One-Dimensional Cellular Automata”. Proceedings of the 9th International Conference on Cellular Automata for Re- search and Industry (ACRI’10). Vol. 6350. Lecture Notes in Computer Science. Springer, 2010, pp. 660–669. [ZGK12] Faried Abu Zaid, Erich Gradel,¨ Łukasz Kaiser. “The Field of Reals is not omega- Automatic”. Proceedings of 29th Annual Symposium on Theoretical Aspects of Computer Science (STACS’12). Vol. 14. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2012, pp. 577–588.

C-COM : International or national conferences without proceedings

• Workshop Numeration, 14–18 June 2010, Lorentz Center, Leiden, Netherlands. V. Berthe.´ • BIRS Outstanding Challenges in Combinatorics on Words, February 2012, Banff, Canada. V. Berthe.´ • KIAS Workshop, Korea, 27 September–1st October 2010. V. Berthe.´

DO : Editing of journals and other works

[AGM08] Eitan Altman, Bruno Gaujal, Jean Mairesse. “Guest Editorial.” Discrete Event Dynamic Systems 18.4 (2008), pp. 445–446. [BM09] Franc¸ois Baccelli, Jean Mairesse. “Guest Editorial.” Queueing Syst. 62.4 (2009), pp. 309– 310. [BR10a] Valerie´ Berthe,´ Michel Rigo, eds. Combinatorics, automata, and number theory. Vol. 135. Encyclopedia of Mathematics and its Applications. 636 pages. Cambridge University Press, 2010. [Mai11] Jean Mairesse. “Foreword: Special section on performance evaluation methodologies.” Discrete Event Dynamic Systems 21.1 (2011), p. 39. [MS12] Jean Mairesse, Giovanni Stea. “Guest Editorial”. Performance Evaluation (2012).

OS : Scientiﬁc works

[Car08] Olivier Carton. Langages formels, calculabilite´ et complexite´. 240 pages. Vuibert, 2008. [Kai11] Łukasz Kaiser. Logic and Games on Automatic Structures. Vol. 6810. Lecture Notes in Artiﬁcial Intelligence. Springer, 2011.

COS : Chapters in scientiﬁc works

[BCL08] Achim Blumensath, Thomas Colcombet, Christof Loding.¨ “Logical theories and compatible operations.” Logic and Automata: History and Perspectives [in Honor of Wolfgang Thomas]. Vol. 2. Texts in Logic and Games. Amsterdam University Press, 2008, pp. 73– 106. [BR10b] Valerie´ Berthe,´ Michel Rigo. “Preliminaries”. Combinatorics, automata, and number theory. Ed. by Valerie´ Berthe´ and Michel Rigo. Vol. 135. Encyclopedia of Mathematics and its Applications. 636 pages. Cambridge University Press, 2010, pp. 1–33. [BST10a] Valerie´ Berthe,´ Anne Siegel, Jorg¨ Thuswaldner. “Substitutions, Rauzy fractals and tilings”. Combinatorics, automata, and number theory. Ed. by Valerie´ Berthe´ and Michel Rigo. Vol. 135. Encyclopedia of Mathematics and its Applications. 636 pages. Cambridge Uni- versity Press, 2010, pp. 248–323.

179 CHAPTER 5. LIST OF PUBLICATIONS: AUTOMATA AND APPLICATIONS

[CPP08a] Olivier Carton, Dominique Perrin, Jean-Eric´ Pin. “Automata and semigroups recognizing infinite words.” Logic and Automata: History and Perspectives [in Honor of Wolfgang Thomas]. Vol. 2. Texts in Logic and Games. Amsterdam University Press, 2008, pp. 133– 168. [CPP08b] Olivier Carton, Dominique Perrin, Jean-Eric´ Pin. “Automata and semigroups recognizing infinite words”. Logic and Automata: History and Perspectives [in Honor of Wolfgang Thomas]. Vol. 2. Texts in Logic and Games. Amsterdam University Press, 2008, pp. 133– 167. [Fro07] Christiane Frougny. “Non-standard number representation: computer arithmetic, beta- numeration and quasicrystals”. Physics and theoretical computer science. Vol. 7. NATO Secur. Sci. Ser. D Inf. Commun. Secur. Amsterdam: IOS, 2007, pp. 155–169. [FS10] Christiane Frougny, Jacques Sakarovitch. “Number representation and finite automata”. Combinatorics, automata and number theory. Vol. 135. Encyclopedia Math. Appl. Cam- bridge: Cambridge Univ. Press, 2010, pp. 34–107. [FZ12] Marie Ferbus-Zanda. “Kolmogorov Complexity in perspective. Part II: Classification, In- formation Processing and Duality”. Logic, Epistemology, and the Unity of Science. To appear. Springer, 2012. [FZG11] Marie Ferbus-Zanda, Serge Grigorieff. “Is Randomness native to Computer Science? Ten Years Later”. Randomness Through Computation: Some Answers, More Questions. Ed. by Hector Zenil. World Scientific, 2011, pp. 243–263. [FZG12] Marie Ferbus-Zanda, Serge Grigorieff. “Kolmogorov Complexity in perspective. Part I: Information Theory and Randomness”. Logic, Epistemology, and the Unity of Science. To appear. Springer, 2012. [GZ08] Hugo Gimbert, Wiesław Zielonka. “Applying Blackwell optimality: priority mean-payoff games as limits of multi-discounted games.” Logic and Automata: History and Perspec- tives [in Honor of Wolfgang Thomas]. Vol. 2. Texts in Logic and Games. Amsterdam University Press, 2008, pp. 331–356. [MY11] Jacques Mazoyer, Jean-Baptiste Yunes.` “Computations on Cellular Automata”. Handbook of Natural Computing. Ed. by Grzegorz Rozenberg, Thomas H.W. Back,¨ and Joost N. Kok. Springer, 2011. [Pin10] Jean-Eric´ Pin. “Automates reversibles:´ combinatoire, algebre` et topologie”. Leçons de mathematiques´ d’aujourd’hui. Ed. by E.´ Charpentier. Vol. 4. Cassini, 2010.

PV : Popularization works √ [Ber11c] Valerie´ Berthe.´ “Nombres et representations.´ Les decimales´ de 2 sont-elles aleatoires?”´ Image des mathematiques´ (2011). URL: http://images.math.cnrs.fr/Nombre s-et-representations.html.

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Appendix: Automata and Applications

6.1 Composition and team organization

Leader: Olivier SERRE (Since January 2011)

Former leader: Jean MAIRESSE

6.1.1 Current members

6.1.1.1 Permanent members (2012)

• Valerie´ BERTHE´, DR CNRS. Since 15/03/2010. • Laurent BIENVENU, CR CNRS. Since 01/10/2009. • Olivier CARTON, Professeur Universite´ Paris Diderot-Paris 7. • Christian CHOFFRUT, Professeur Universite´ Paris Diderot-Paris 7. • Thomas COLCOMBET, CR CNRS. Since 01/07/2007. • Marie FERBUS-ZANDA, Maˆıtre de conference´ Paris Diderot-Paris 7. • Christiane FROUGNY, Professeur em´ erite´ Universite´ Paris 8. • Mai GEHRKE, DR CNRS. Since 01/10/2011. • Serge GRIGORIEFF, Professeur em´ erite´ Universite´ Paris Diderot-Paris 7. • Łukasz KAISER, CR CNRS. Since 01/10/2010. • Ines KLIMANN, Maˆıtre de conference´ Paris Diderot-Paris 7. • Jean MAIRESSE, DR CNRS. • Sylvain PERIFEL, Maˆıtre de conference´ Paris Diderot-Paris 7. Since 01/09/2008. • Matthieu PICANTIN, Maˆıtre de conference´ Paris Diderot-Paris 7. • Jean-Eric´ PIN, DR CNRS. • Olivier SERRE, CR CNRS. • Wolfgang STEINER, CR CNRS. • Jean-Baptiste YUNES` , Maˆıtre de conference´ (HdR) Paris Diderot-Paris 7. • Wiesław ZIELONKA, Professeur Universite´ Paris Diderot-Paris 7.

6.1.1.2 Ph.D students and post-doctoral researchers (2012)

PhD students

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• Dion COUMANS. Advisor: M. Gehrke. • Luc DARTOIS. Advisors: O. Carton and J.-E.´ Pin. • Laure DAVIAUD. Advisors: T. Colcombet and J.-E.´ Pin. • Axel HADDAD. Advisor: A. Carayol (LIGM, Universite´ Paris Est) and O. Serre. • Timo JOLIVET. Advisors: J. Kari (Turku, Finland) and V. Berthe.´ • Denis KUPERBERG. Advisors: O. Carton and T. Colcombet. • Irene` MARCOVICI. Advisor: J. Mairesse. • Benoˆıt MONIN. Advisor: L. Bienvenu and E. Asarin (Equipe´ Modelisation´ et veriﬁcation).´ • Charles PAPERMAN. Advisors: O. Carton and J.-E.´ Pin. • Yann PEQUIGNOT. Advisors: J. Duparc (Universite´ de Lausanne, Switzerland) and J.-E.´ Pin. • Antoine TAVENEAUX. Advisors: L. Bienvenu and S. Laplante (Equipe´ Algorithmique et complexite).´ • Sam VAN GOOL. Advisor: M. Gehrke. • Lorijn VAN ROOIJEN. Advisors: M. Gehrke and M. Zeitoun (Universite´ de Bordeaux 1).

Post-doctoral researchers

• Christopher BROADBENT (funded by Fondation Sciences Mathematiques´ de Paris). From 28/09/2011 to 01/10/2012. • Stefan GOLLER¨ (funded by ERC project GALE). From 05/03/2012 to 30/09/2012. • Matthew HAGUE (funded by region´ Ileˆ de France). From 01/09/2011 to 31/08/2012. • Rupert HOLZL¨ (funded by a Feodor Lynen Research Fellowship by the Alexander von Humboldt Foundation). From 04/01/2011 to 31/12/2012. • Christos KAPOUTSIS (funded by a Marie Curie fellowship). From 01/09/2010 to 31/08/2012. • Luidnel MAIGNAN (ATER, Universite´ Paris Diderot-Paris 7). From 01/09/2011 to 30/08/2012. • Amaldev MANUEL (funded by ERC project GALE). From 02/04/2012 to 02/04/2014.

6.1.2 Former members

6.1.2.1 Permanent members (2007-2011)

• Luc BOASSON, Professeur Universite´ Paris Diderot-Paris 7. Retired since 01/09/2010.

6.1.2.2 Ph.D students and post-doctoral researchers (2007-2011)

PhD Students • Marie ALBENQUE, Tresses, animaux, cartes : a` l’interaction entre combinatoire et probabilites´ . Advisors: J.-F. Marckert (LaBRI, Universite´ de Bordeaux 1) and J. Mairesse. Defended 3/12/2008. M. Albenque is now a CNRS researcher at LIX (Ecole´ Polytechnique). • Jer´ emie´ CABESSA, A game theoretical approach to the algebraic counterpart of the Wagner hierarchy. Advisors: J. Duparc (Universite´ de Lausanne, Switzerland) and J.-E.´ Pin. Defended 28/08/2007. J. Cabessa is now a charge´ de cours at UNI Lausanne and EPFL Lausanne. • Laura CHAUBARD, Methodes´ algebriques´ pour les langages formels. Applications a` la logique et a` la dynamique symbolique. Advisor: J.-E.´ Pin. Defended 05/04/2007. L. Chaubard is now an engineer at DGA.

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• Julien CRISTAU, Automates et logique temporelle sur les ordres lineaires´ . Advisor: O. Carton. Defended 13/12/2010. J. Cristau is now an engineer at Logilab. • Thu-Ha DAO-THI, Les ﬁles et les reseaux zero-automatiques. Advisor: J. Mairesse. Defended 03/11/2007. T.-H. Dao-Thi is now a CNRS researcher at PRISM (Universite´ de Versailles Saint- Quentin-en-Yvelines).

• Achille FRIGERI, Problemes` de deﬁnissabilit´ e´ logiques sur N, Z et Zp: applications des automates ﬁnis. Advisor: C. Choffrut. Defended 24/03/2009. A. Frigeri is now a temporary research assistant at the Department of Electronics and Computer Science of the Politecnico di Milano. • Guillaume DELALLEAU, Substitutions sur la droite et dans le plan. Advisor: V. Berthe.´ Defended 17/11/2011. • Karel KLOUDA, Combinatorics on beta-numeration. Advisors: Ch. Frougny and E. Pelantova (CTU, Prague, Czech Republic). Defended 19/11/2010. K. Klouda is now an assistant-professor at CTU Prague. • Sebastien´ LABBE´, Structure des pavages, droites discretes` 3D et combinatoire des mots. Advi- sors: V. Berthe´ & S. Brlek (Universite´ du Quebec,´ Canada). Defended 4/05/2012. S. Labbe´ has just received a two-year postdoc grant from FQRNT (Quebec).´ • Anna Chiara LAI, On expansions in non-integer base. Advisors: Ch. Frougny and P. Loreti (Universita La Sapienza, Roma, Italy). Defended 09/03/2010. A. C. Lai is now a postdoctoral researcher at Universita La Sapienza, Roma. • Hoang-Thach NGUYEN, Reseaux de Petri stochastiques a forme produit. Advisor: J. Mairesse. Defended 18/04/2012. H.-T. Nguyen will start a postdoc soon.

Post-doctoral researchers • Ali AKHAVI (maˆıtre de conference´ universite´ de Caen, del´ egation´ CNRS). From 01/09/2005 to 31/08/2007. • Achim BLUMENSATH (funded by ERC project GALE). From 01/04/2011 to 01/05/2012. • Ana BUSIˇ C´ (funded by ANR project MASED). From 01/09/2008 to 31/08/2009. • Lucas GERIN (funded by GAMMA). From 01/01/2009 to 31/08/2010 • Zur IZHAKIAN (funded by ESF AutoMathA project). 6 months in 2008. • Roberto MERCAS (funded by the Spanish Ministry for research). From 01/01/2010 to 01/07/2010. • Glenn MERLET (funded by ANR project MASED). From 01/09/2006 to 31/08/2007. • Eric´ THIERRY (maˆıtre de conference´ universite´ ENS´ de Lyon, del´ egation´ CNRS). From 01/09/2007 to 31/08/2009. • Konrad ZDANOWSKI (funded by ANR project JADE). From 01/09/2008 to 31/08/2009.

6.1.2.3 Long-term visitors (2007-2011)

• Mai GEHRKE (University of Nijmegen, Netherlands). 6 month (2010).

6.1.2.4 Others (2007-2011)

We list below the students that made an internship in our group while they were Master students (2nd year) in France.

• Florent CAPELLI (ENS´ Lyon), 2011. • Luc DARTOIS (ENS´ Cachan), 2010.

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• Laure DAVIAUD (ENS´ Cachan), 2011. • Antoine DELIGNAT-LAVAUD (ENS´ Cachan), 2011. • David DURRLEMAN (ENS´ Paris), 2008. • Axel HADDAD (ENS´ Cachan), 2010. • Denis KUPERBERG (ENS´ Lyon), 2009. • Irene` MARCOVICI (ENS´ Lyon), 2009. • Benoˆıt MONIN (ENS´ Lyon), 2011. • Hoang-Thach NGUYEN (Ecole´ Polytechnique), 2008. • Charles PAPERMAN (Universite´ Paris Diderot-Paris 7), 2011. • Antoine TAVENEAUX (ENS´ Lyon), 2010.

We list below the students that made an internship in our group while they were Master students (1st year) in France.

• Nathaniel CARRE´ (Ecole´ Polytechnique), 2011. • Guillaume LAGARDE (ENS´ Lyon), 2012.

6.1.3 Visitors

The following researchers have visited the group: • Ver´ onica´ BECHER (University of Buenos Aires, Argentina). 1 month (2007), 1 month (2008), 2 weeks (2009), 2 weeks (2010), 2 weeks (2012). • Mai GEHRKE (University of Nijmegen, Netherlands). 1 months (2008). • Peter GRABNER (TU Graz, Austria). 1 month (2007). • Noam GREENBERG (Victoria University of Wellington, New Zealand). 1 month (2011). • Juhani KARHUMAKI¨ (Turku University, Finland). 1 month (2008). • Jarkko KARI (Turku University, Finland). 1 month (2012). • Cor KRAAIKAMP (TU Delft, Netherlands). 1 month (2009). • Christof LODING¨ (RWTH Aachen, Germany). 1 month (2008). • Andre´ NIES (University of Auckland , New Zealand). 1 month (2011). • Jorg¨ THUSWALDNER (Montanuniversitat¨ Leoben, Austria). 1 month (2011). • Hiroshi UMEO (Osaka University, Japan). 1 month (2009).

6.1.4 Team organization

6.1.4.1 Funding and resource management

See Section 1.4

6.1.4.2 Team activities

There are several seminars/working groups within the team. The one currently active are listed below. • A weekly seminar. Information available at http://www.liafa.univ-paris-diderot.fr/web9/manifsem/listmanifannee fr.php?typecongres=3 • A reading group (taking place every two weeks) on Calculability, Complexity and Randomness.

184 CHAPTER 6. APPENDIX: AUTOMATA AND APPLICATIONS

• A weekly working group on Recognisability (ANR FREC). • A reading group on Logic, Automata, Algebra and Games. Information available at http://www.liafa.univ-paris-diderot.fr/∼colcombe/RG LAG en.html Along the period some other working groups have been active. • A monthly working group on Games (co-organised with LSV): 2008–2010. • A weekly reading group on the book of S. Arora et B. Barak, Computational Complexity: A Modern Approach: 2010–2011. • A working group on Mixing Times: 2011–2012. • A working group on Discrete Event Systems. Information available at http://liafa.jussieu.fr/∼klimann/SED/#exposes

6.1.4.3 Participation in the scientiﬁc community and administrative responsibilities

In CNRS • From 2007 to 2010, V. Berthe´ was Chargee´ de mission Interface Mathematiques-Informatique´ for the INS2I and INSMI institutes from CNRS. • Since 2011, J. Mairesse is Charge´ de mission Interface Mathematiques-Informatique´ for the INS2I and INSMI institutes from CNRS.

In Foundations, in Federations • Since 2011, V. Berthe´ is deputy-director of the Fondation Sciences Mathematiques´ de Paris. • Since 2010, J. Mairesse is deputy-director of the Fed´ eration´ de Recherche en Mathematiques´ de Paris Centre (FR 2830).

In groupements de recherche (GdR) • From 2006 to 2009, Ch. Frougny was deputy-director of GDR 673 of CNRS Informatique Mathematique´ (IM). • Since 2009, Ch. Frougny is a member of steering committee of GDR IM, in charge of young actions. • Since 2008 V. Berthe´ is a member of the scientiﬁc council of GDR Calcul Scientiﬁque (GDR 3275). • From 2006 to 2010, J. Mairesse was the head of the working group SDA2: Systemes` Dynamiques, Automates et Algorithmique of GDR IM. • Since 2010, V. Berthe´ is the co-head with Guillaume Theyssier (LAMA, universite´ de Savoie) of the working group SDA2: Systemes` Dynamiques, Automates et Algorithmique of GDR IM.

In steering commitees, executive boards or scientiﬁc councils of international and national structures • Since 2009 J. Mairesse is a member of the Steering Committee of the Ecole´ de Printemps d’Informatique Theorique´ . • Since 2009, M. Gehrke is a member of the executive board of Discrete, Interactive and Algorith- mic Mathematics, Algebra and Number Theory (DIAMANT), one of the four mathematics clusters in the Netherlands. • Since 2007, J. Mairesse is a member of the executive board of the Societ´ e´ de Mathematiques´ Appliquees´ et Industrielles (SMAI).

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• From 2004 to 2010, J. Mairesse was a member of the executive board of the group MAS (Modeles` Aleatoires´ et Statistiques) of the SMAI. • Since 2011, V. Berthe´ is a member of the scientific council of the city of Paris. • Since 2004, V. Berthe´ is a member of the scientific council of the Centre International de rencontres mathematiques´ (CIRM). • Since 2009, M. Gehrke is a member of the scientific board of the Lorentz International Center for workshops in the Sciences. • Since 2010, V. Berthe´ is a member of the scientific council Reseau´ Africain de Geom´ etrie´ et Algebre` Appliquees´ au developpement´ (RAGAAD). • Since 2011, J.-E.´ Pin is a member of the council of EATCS (European Association of Theoretical Computer Science). In the university • From 2008 to 2010, J. B. Yunes` was a Charge´ de Mission at Universite´ Paris Diderot-Paris 7 for the Technologie de l’Information et de la Communication pour l’Enseignement (TICE). • Until 2008, C. Choffrut was the head of the Thesis committee for computer science at Universite´ Paris Diderot-Paris 7. In Research team heading • From 2006 to 2010, J. Mairesse was the head of the team Automates et Applications. • Since 2011, O. Serre is the head of the team Automates et Applications. 6.2 Grants and research projects

6.2.1 Management of international projects

AutoMathA (2005–2010). Type of project: Research Networking Programme of the European Science Foundation. Full title: Automata: From mathematics to applications. Partners: 15 European countries. Head: J.-E.´ Pin . Global budget: 600Ke. In LIAFA, all researchers from the Auto- mates et applications group were involved in the project, as well as some researchers from the Modelisation´ et Verification´ group. GALE (2011–2014). Type of project: ERC starting independent researcher grant. Full title: Games, Automata, and Logics’ Extensions. Partners: LIAFA. Coordinator: T. Colcombet. Budget (for LIAFA): 930Ke In LIAFA, the researchers involved in the project are Thomas Colcombet, Achim Blumensath, Laure Daviaud, Stefan Goller¨ and Amaldev Manuel. Algorithmic Randomness for Non-Uniform Measures (2011–2012). Type of projet: Project France- Berkeley. Partners: LIAFA, LIRMM (CNRS et Universite´ de Montpellier 2) and University of California Berkeley (USA). Coordinator: L. Bienvenu. Montant de la collaboration (pour le LI- AFA): 7Ke. In LIAFA, the researchers involved in the project are L. Bienvenu and his PhD students. Non-standard representation of numbers: combinatorics, dynamics and finite automata (2007– 2008). Type of project: PHC Amadeus. Partners: LIAFA and TU Graz (Austria). Coordinators: Ch. Frougny and Peter Grabner (TU Graz). Budget (for LIAFA): 4ke In LIAFA, the researchers involved in the project were Ch. Frougny and W. Steiner. Games for synthesis and verification of reactive systems (2007–2008). Type of project: PHC Polo- nium. Partners: LIAFA and Department of Computer Science (Warsaw University, Poland). Co- ordinators: W. Zielonka and D. Niwinski.In LIAFA, the researchers involved in the project were O. Serre and W. Zielonka.

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Suites inﬁnies et aleatori´ et´ e´ algorithmique (2006–2008). Type of project: Bilateral project programme SECyT-FRIC. Partners: LIAFA and Universidad de Buenos Aires (Argentina). Coordi- nator: J.-E.´ Pin and V. Becher. In LIAFA, the researchers involved in the project were O. Carton, S. Grigorieff and J.-E.´ Pin. Aleatori´ et´ e´ et combinatoire des mots (2009–2010). Type of project: Bilateral project MINCyT- IN- RIA/CNRS 2009-2010. Partners: LIAFA and Universidad de Buenos Aires (Argentina). Coordi- nator: J.-E.´ Pin and V. Becher. In LIAFA, the researchers involved in the project were L. Bienvenu, O. Carton, S. Grigorieff, J.-E.´ Pin and M. Rafﬁnot. PHC Picasso (2009–2010). Type of project: PHC Picasso. Partners: LIAFA and Universitad de Va- lencia (Spain). Coordinator: J.-E.´ Pin and A. Ballester-Bolinches. Budget (for LIAFA): 2500e In LIAFA, the researchers involved in the project were O. Carton, C. Choffrut, J. Cristau and J.-E.´ Pin.

6.2.2 Management of national projects

MASED (2006–2009). Type of project: ANR Jeunes chercheuses et jeunes chercheurs. Full title: Marches Aleatoires´ et Systemes` a` Ev´ enements´ Discrets. Partners: LIAFA. Coordinator: J. Mairesse. Budget (for LIAFA): 120Ke In LIAFA, the researchers involved in the project were M. Albenque, A. Akhavi, A. Busiˇ c,´ I. Klimann, J. Mairesse, G. Merlet and M. Picantin. DyCoNum (2006–2010). Type of project: ANR Jeunes chercheuses et jeunes chercheurs. Full title: Etudes´ diophantiennes, dynamiques et combinatoires de differentes´ numeations.´ Partners: LI- AFA, IRISA (CNRS et Universite´ de Rennes 1) and Institut Camille Jordan (CNRS et Universite´ Claude Bernard Lyon 1). Coordinator: W. Steiner. Budget (for LIAFA): 38Ke In LIAFA, the researchers involved in the project were Ch. Frougny and W. Steiner. JADE (2008–2012). Type of project: ANR Jeunes chercheuses et jeunes chercheurs. Full title: Jeux, Automates, Decidabilit´ e´ et Extensions. Partners: LIAFA. Coordinator: T. Colcombet. Budget (for LIAFA): 90Ke In LIAFA, the researchers involved in the project were T. Colcombet and O. Serre. Mathematically and Computationally Relevant Dualities (2009–2013). Type of project: Nether- lands National Project. Partners: LIAFA and University of Nijmegen (Netherlands). Head: M. Gehrke . Budget (for LIAFA): 2 PhD grants. In LIAFA, the researchers involved in the project are Mai Gehrke and Sam van Gool.

6.2.3 Management of local projects

Groupes d’automates (2010–2011). Type of project: Projet inter-disciplinaire Univ. Paris Diderot- Paris 7. Partners: LIAFA and IMJ (CNRS, Univ. Pierre et Marie Curie et Univ. Paris Diderot). Head (for LIAFA): J. Mairesse. Budget (for LIAFA): 8ke. In LIAFA, the researchers involved in the project were I. Klimann, M. Picantin, J. Mairesse.

6.2.4 Participation in international projects

GASICS (2008–2011). Type of project: EuroCORE of the European Science Foundation. Full title: Games for . Partners: CFV (Centre fed´ er´ e´ en veriﬁcation,´ Belgium), RWTH Aachen (Germany), Aalborg University (Denmark), LSV (ENS´ Cachan), LIAFA and Unviersity of Warwick (UK). Coordinator: J.-F. Raskin (CFV). In LIAFA, the researchers involved in the project were N. Fi- jalkow, F. Horn, F. Laroussinie, J.-E.´ Pin and O. Serre. Proyecto MTM2010-19938-C03-01 (2010–2012). Type of project: Project funded by MICINN (Spain). Full title: Propiedades aritmeticas y estructurales de los grupos. Aplicaciones. Coor- dinator: A. Ballester-Bolinchers (Universidad de Valencia). In LIAFA, the researcher involved in the project is J.-E.´ Pin.

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Fractals and topological structures arising from dynamics (2008–2009). Type of project: PHC Amadeus. Partners: IRISA (CNRS, INRIA et Univ. Rennes 1), LIAFA, LIRMM (CNRS and Universite´ Montpellier 2), Montanuniversitat¨ Leoben (Austria) and TU Wien (Austria). Coordi- nators: V. Berthe´ (LIRMM) and J. Thuswaldner (Leoben). In LIAFA, the researcher involved in the project was W. Steiner. From fractals to numeration (2011–2012). Type of project: PHC Amadeus. Partners: IML (Univer- site´ d’Aix-Marseille), IRISA (CNRS, INRIA et Univ. Rennes 1), LIAFA, LIRMM (CNRS and Universite´ Montpellier 2), and Montanuniversitat¨ Leoben (Austria) and TU Wien (Austria). Co- ordinators: A. Siegel (IRISA) and J. Thuswaldner (Leoben). In LIAFA, the researchers involved in the project are V. Berthe´ and W. Steiner. Principe variationnel et points gen´ eriques´ dans systemes` dynamiques (2012). Type of project: PHC Orchid. Partners:LAMA (CNRS and Universite´ Paris-Est Creteil´ Val de Marne), LAMFA (CNRS, Universite´ de Picardie Jules Verne), LIAFA, and National Dong Hwa University (Taiwan, China). Coordinators: L. Liao (LAMA) and J.-C. Ban (National Dong Hwa University). In LIAFA, the researcher involved in the project is W. Steiner.

6.2.5 Participation in national projects

LAREDA (2007–2009). Type of project: . Full title: Lattice Reduction Algorithms: Dynamics, Prob- abilities, Experiments, Applications. Partners: GREYC (CNRS et Universite´ de Caen), LIRMM (CNRS et Universite´ Montpellier 2), IRISA (CNRS, INRIA et Universite´ de Rennes 1), LIP (CNRS et ENS´ Lyon) and IMB (CNRS et Universite´ de Bourgogne). Coordinator: Brigitte Vallee´ (GREYC). Coordinator in LIAFA: V. Berthe´ 1. In LIAFA, the researcher involved in the project was V. Berthe.´ SubTile (2009–2012). Type of project: ANR blanche. Full title: Substitutions et pavages. Partners: CPHT, Institut Camille Jordan, IGM, IML, IMT, LAMFA, LATP, LIF, LIP, LIRMM, LMO, and Laboratoire J.-A. Dieudonne.´ Coordinator: P. Arnoux (IML). In LIAFA, the researcher involved in the project is V. Berthe.´ Kidico (2010–2013). Type of project: ANR Blanche. Full title: Knowledge Integration for Digital convolution, Image Segmentation and Measurement. Partners: LSIIT, LIAFA, LORIA, LIMOS, ISIT, LAMA, LIRMM, I3M and LIGM. Coordinator: M. Tajine (LSIIT). In LIAFA, the researcher involved in the project is V. Berthe.´ Categorical and Algebraic Models of Computation (2010–2013). Type of project: Netherlands national project. Partners: LIAFA and . Coordinator: Henk Barendregt (University of Nijmegen, Netherlands). Budget (for LIAFA): 1 year postdoctoral grant. In LIAFA, the researcher involved in the project is Mai Gehrke. FREC (2010–2014). Type of project: ANR Blanche. Full title: Frontieres` de la reconnaissabilite.´ Part- ners: LaBRI and LIAFA. Coordinator: Pascal Weil (LaBRI). Coordinator in LIAFA: J.-E.´ Pin. Budget (for LIAFA): 208ke. In LIAFA, the researchers involved in the project are O. Carton, T. Colcombet, L. Daviaud, L. Dartois, M. Gehrke, N. Fijalkow, D. Kuperberg, C. Paperman, J.- E.´ Pin, Y. Pequignot and O. Serre. AMIS (2011–2014). Type of project: ANR Jeunes chercheuses et jeunes chercheurs. Full title: Algo- rithmic Methods for Inﬁnite Structures. Partners: LIGM and LIAFA. Coordinator: A. Carayol (LIGM). Coordinator in LIAFA: O. Serre. In LIAFA, the researchers involved in the project are O. Serre and A. Haddad.

1. Actually the project was still managed in LIRMM

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6.3 Research administration

6.3.1 Editorial duties

6.3.1.1 Editorial board chair

RAIRO ITA. C. Choffrut and O. Serre are editor in chief of the journal RAIRO ITA

6.3.1.2 Editorial board member

Annals of Applied Probability. Since 2010, J. Mairesse is an editor. Queueing Systems. Since 2009, J. Mairesse is an editor. International Journal of Algebra and Computation. J.-E.´ Pin is an editor. RAIRO ITA. Since 2010, O. Carton is an editor. Semigroup Forum. J.-E.´ Pin is an editor and a member of the council. The Houston Journal of Mathematics. Since 2009, M. Gehrke is an editor.

6.3.2 Management of scientiﬁc conferences

6.3.2.1 Steering committee chair

AutoMathA. Automata: from Mathematics to Applications. J.-E.´ Pin (2007–2010).

6.3.2.2 Steering committee member

GandALF. International Symposium on Games, Automata, Logics and Formal Veriﬁcation. W. Zielonka (since 2011). CCR. Computability, Complexity and Randomness. L. Bienvenu (2010–2013). TACL Topologies, Algebras, and Categories in Logic. M. Gehrke (since 2003).

6.3.2.3 Program committee chair

VALUETOOLS 2009 4th Int. Conf. on Performance Evaluation Methodologies and Tools, IEEE, Pisa, Italy, 2009. J. Mairesse. Stochastic Networks 2008 8th Stochastic Networks Conference, Paris, 2008 J. Mairesse (with F. Bac- celli).

6.3.2.4 Program committee member

AFL 2008 Automata and Formal Languages, Balatonfered,´ 2008. O. Carton and Christian Choffrut. The Algebra and Geometry around Knots and Braids St-Petersbourg, 2007. J. Mairesse. ALCOP 2012 Algebra and Coalgebra meet Proof Theory, Prague, 2012. M. Gehrke. ARITH 18 IEEE International Symposium on Computer Arithmetic, Montpellier, 2007. Ch. Frougny. AUTOMATA 2010 International workshop on Cellular Automata and Discrete Complex Systems, Nancy, 2010. J.-B. Yunes.` Colloque a` l’occasion du 60eme` anniversaire de B. Vallee´ Nombres, Sequences,´ Reseaux´ : analyse dynamique d’algorithmes, Caen, 2010. V. Berthe´ CALCO 2007 Conference on Algebra and Coalgebra in Computer Science, Bergen, 2007. J.-E.´ Pin. CALCO 2009 Conference on Algebra and Coalgebra in Computer Science, Udine, 2009. J.-E.´ Pin.

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CANT 2012 Combinatorics, Automata and Number Theory, Marseille, 2012. J. Mairesse. CCR 2010 Computability, Complexity and Randomness, Notre Dame, 2010. L. Bienvenu. CCR 2011 Computability, Complexity and Randomness, Cape Town, 2011. L. Bienvenu. CCR 2012 Computability, Complexity and Randomness, Cambridge, 2012. L. Bienvenu. CIAA 2007 International Conference on Implementation and Application of Automata, Prague, 2007. J.-E.´ Pin. CMCS 2012 Coalgebraic Methods in Computer Science, Tallinn, 2012. M. Gehrke. CSL 2007 Computer Science Logic, Lausanne, 2007. J.-E.´ Pin. CSR 2009 Computer Science Symposium in Russia, Ekaterinburg, 2007. J.-E.´ Pin. CSR 2011 Computer Science Symposium in Russia, Saint-Petersburg, 2011. O. Carton. DLT 2008 Developments in Language Theory, Kyoto, 2008. O. Carton. DLT 2011 Developments in Language Theory, Milano, 2011. C. Choffrut. FCT 2007 Foundations of Computer Science, 2007. J.-E.´ Pin. FINCO 2007 Foundations of Interactive Computation, 2007. J.-E.´ Pin. Forum Jeunes mathematiciennes´ V. Berthe´ (2010–2013). FoSSaCS 2011 Foundations of Software Science and Computational Structures, 2011. O. Serre. FST&TCS 2012 IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science, 2012 T. Colcombet. GaLoP 2009 Games for Logic and Programming Languages, 2009. O. Serre. GANDALF 2011 International Symposium on Games, Automata, Logics and Formal Verification, Mi- nori, 2010. T. Colcombet. ICALP 2008 International Colloquium on Automata Languages and Programming, Reykjavik, 2008. W. Zielonka. ICALP 2009 International Colloquium on Automata Languages and Programming, Rhodes, 2009. C. Choffrut. IFIP TCS 2010 6th IFIP International Conference on Theoretical Computer Science, Brisbane, 2010. V. Berthe.´ INFINITY 2008 10th International Workshop on Verification of Infinite-State Systems, Toronto,2008. T. Colcombet. IWIGP 2011 International Workshop on Interactions, Games and Protocols, Saarbrucken, 2011. W. Zielonka. JAC 2010 Journees Automates Cellulaires, Turku, 2010. J. Mairesse. JMC 2012 Journees´ Machines a` etats´ finis et Combinatoire, Rouen, 2012. J. Mairesse. Journees´ Montoises 2010 13emes` Journees´ Montoises d’Informatique Theorique´ , Amien, 2010. V. Berthe´ and J. Mairesse. LATA 2008 Conference on Language and Automata Theory and Applications, Tarragona, 2008. Ch. Frougny and J.-E.´ Pin. Laminations and symbolic dynamics 2012 , Marseille, 2012. V. Berthe.´ LATIN 2008 American Theoretical Informatics Symposium, 2008. J.-E.´ Pin. MFCS 2008 International Symposium of Computer Science, Torun, 2008. W. Zielonka. MFCS 2009 International Symposium of Computer Science, 2009. J.-E.´ Pin.

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MFCS 2010 International Symposium of Computer Science, 2010. T. Colcombet and J.-E.´ Pin. Numeration 2011 , Liege,` 2011. V. Berthe,´ Ch. Frougny and W. Steiner. RNC 2007 7th Conference on Real Numbers and Computers, 2007. Ch. Frougny. SOFSEM 2008 Current Trends in Theory and Practice of Computer Science, High Tatras, 2008. C. Choffrut and W. Zielonka. SOFSEM 2010 Current Trends in Theory and Practice of Computer Science, , 2010. O. Serre. SOFSEM 2012 Current Trends in Theory and Practice of Computer Science, Spindleruv Mlyn, 2012. W. Zielonka. STACS 2009 Annual Symposium on Theoretical Aspects of Computer Science, 2009. Ch. Frougny. STACS 2011 Annual Symposium on Theoretical Aspects of Computer Science, Dortmund, 2011. C. Choffrut and T. Colcombet. Stochastic Networks Conference 2010 Cambridge, 2010. J. Mairesse. WORDS 2009 7th International Conference on Words, Salerno, 2009. C. Choffrut. WORDS 2011 7th International Conference on Words, Prague, 2011. Ch. Frougny.

6.3.3 Organization of scientiﬁc events

6.3.3.1 Local arrangements committee chair

International Conferences: Stochastic Networks 2008. Conference organised in ENS,´ Paris, June 2008. J. Mairesse (with F. Bac- celli). Numeration: Mathematics and Computer Science. Conference organised in CIRM, Marseille, 23– 27 March 2009. W. Steiner. International School: CANT’12. International School and Conference on Combinatorics, Automata and Number Theory, CRIM, Marseille, May 2012. V. Berthe.´ Workshops: JORCAD’08. Workshop organised in Rouen, September 2008. J. Mairesse. ALEA’09. Workshop organised in CIRM, Marseille, March 2009. J. Mairesse (with A. Micheli and D. Poulalhon). Distance Automata and Generalisations Workshop organised in LIAFA, Paris, 16–18 November 2009. T. Colcombet. FRAC-SDA2-NAFIT. Workshop organised in Nice, December 2009. J. Mairesse. Recursion Schemes and Pushdown Automata. Workshop organised in LIAFA, Paris, 25–26 March 2010. O. Serre. Digital expansions, dynamics and tilings. Workshop organised in Aussois, 4–10 April 2010. W. Steiner. GT Jeux. Workshop of the GT CMF (GDR-IM), Paris, 25–26 October 2010. O. Serre Automata and logic for data manipulating programs. Workshop organised in LIAFA, Paris, 7–8 De- cember 2010. Ł. Kaiser and O. Serre. Computability and randomness. Workshop organised in LIAFA, Paris, 7–8 June 2011. L. Bienvenu. GT CMF. Workshop of the GT CMF (GDR-IM), Paris, 22–24 June 2011. S. Perifel. Journees´ Calculabilites.´ Workshop organised in LIAFA, Paris, 5–6 March 2012. L. Bienvenu.

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6.3.3.2 Local arrangements committee member

Journees´ d’Informatique Mathematique.´ Annual worskhop of GDR IM organised in Paris since 2007. Ch. Frougny. Ecole´ Jeunes Chercheurs. Annual school of GDR IM organised in France since 2007. Ch. Frougny. Numeration 2008 . Conference organised in Prague, 26–30 May 2008. Ch. Frougny and W. Steiner. Equational Theory of Regular Languages. Workshop organised in Brno, 5–6 March 2009. J.-E.´ Pin. Automata and Algorithmic Logic. Workshop organised in Stuttgart, 28–29 June 2010. T. Colcombet. Logic Colloquium (LC 2010). Conference organised in Paris, July 2010. T. Colcombet and J.-E.´ Pin. Combinatorics on Words. Workshop organised in Mathematisches Forschungsinstitut Oberwolfach, 22-28 August 2010. V. Berthe´ (with J. Karhumaki,¨ D. Nowotka and J. Shallit). FoSSaCS 2010. International Conference on Foundations of Software Science and Computational Structures, Paris, 31 August–3 September 2010. O. Serre. Computability, Complexity and Randomness. Workshop organised in Dagstuhl, 9–13 January 2011. L. Bienvenu. Workshop on Sand Pile Model. Workshop organised in LIAFA, Paris, 7–8 April 2011. J.-B. Yunes.` GAMES 2011. Annual Workshop of the ESF Networking Programme on Games for Design and Veri- ﬁcation, Paris, 31 August–3 September 2011. T. Colcombet, O. Serre and W. Zielonka.

6.3.4 Participation in scientiﬁc juries and committees

6.3.4.1 International

CAUL. Member of the Advisory Committee, Centro de Algebra´ da Universidade de Lisboa (Portugal). J.-E.´ Pin. FNRS. Expert for the Fonds de la Recherche Scientiﬁque (Belgium). J. Mairesse.

6.3.4.2 National

ANR blanche et JCJC Member of Comite´ Scientiﬁque Disciplinaire. Christiane Frougny (2007), Jean Mairesse (2007–2008). PEDR Member of jury PEDR, 2008. Christiane Frougny. AERES Evaluateur´ . Christiane Frougny, Jean Mairesse.

6.3.4.3 Commissions of specialists

Ecole´ Normale Superieure´ de Cachan O. Serre (2012) IUT de Fontainebleau 2012 Christian Choffrut (2012) Universite´ de Besanc¸on I. Klimann (2008–2009), Universite´ Bordeaux 1 W. Zielonka (2012), J. Mairesse (2007–2008,2009,2010, 2011: chaire CNRS, 2012), O. Serre (2011: chaire CNRS, 2012) Universite´ de Caen J. Mairesse (2007–2008) Universite´ de Cergy-Pontoise Ch. Frougny (2009) Universite´ Joseph Fourier, Grenoble V. Berthe´ (2010: chaire CNRS), J. Mairesse (2011: chaire CNRS)

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Universite´ de la Mediterran´ ee´ (Aix-Marseille II) C. Choffrut (2008), W. Steiner (2009), T. Colcom- bet (2012) Universite´ de Montpellier 2 V. Berthe´ (2011), J. Mairesse (2011, 2012) Universite´ de Nice V. Berthe´ (2012,2011,2010: chaire CNRS) Universite´ Paris Diderot – Paris 7 Ch. Frougny (2007–2008), J. Mairesse (2007–2008, 2009), S. Per- ifel (2010), O. Serre (2007–2008), V. Berthe´ (2012) Universite´ Paris-Est Marne-la-vallee´ I. Klimann (2007), T. Colcombet (2009: chaire CNRS), Ch. Frougny (2009–2010), J. Mairesse (2010) Universite´ Paris Sud S. Perifel (2010) Universite´ de Provence (Aix-Marseille I) M. Gehrke (2012), S. Grigorieff (2007–2008), O. Serre (2007–2008) Universite´ de Rouen C. Choffrut (2007–2008), Ch. Frougny (2008–2010) Universite´ de Strasbourg V. Berthe´ (2012) Universite´ de Versailles St-Quentin-en-Yvelines V. Berthe´ (2010: chaire CNRS), J. Mairesse (2012: chaire CNRS)

6.4 Teaching, advising, and evaluation activities

6.4.1 Theses and HdR defended

6.4.1.1 Habilitations a` diriger les recherches

J.-B. Yunes.` A` propos d’automates cellulaires suivi par Des fonctions Booleennes´ . Defended 12/12/2007.

6.4.1.2 Doctoral theses

Marie ALBENQUE. Tresses, animaux, cartes : a` l’interaction entre combinatoire et probabilites´ . Ad- visors: J.-F. Marckert (LaBRI, Universite´ de Bordeaux 1) and J. Mairesse. Defended 3/12/2008. Jer´ emie´ CABESSA. A game theoretical approach to the algebraic counterpart of the Wagner hierarchy. Advisors: J. Duparc (Universite´ de Lausanne, Switzerland) and J.-E.´ Pin. Defended 28/08/2007. Laura CHAUBARD. Methodes´ algebriques´ pour les langages formels. Applications a` la logique et a` la dynamique symbolique. Advisor: J.-E.´ Pin. Defended 05/04/2007. L. Chaubard is now an engineer at DGA. Julien CRISTAU. Automates et logique temporelle sur les ordres lineaires´ . Advisor: O. Carton. De- fended 13/12/2010. Guillaume DELALLEAU. Substitutions sur la droite et dans le plan. Advisor: V. Berthe.´ Defended 17/11/2011. Thu-Ha DAO-THI. Les ﬁles et les reseaux zero-automatiques. Advisor: J. Mairesse. Defended 03/11/2007.

Achille FRIGERI. Problemes` de deﬁnissabilit´ e´ logiques sur N, Z et Zp: applications des automates ﬁnis. Advisor: C. Choffrut. Defended 24/03/2009 Karel KLOUDA. Combinatorics on beta-numeration. Advisors: Ch. Frougny and E. Pelantova (CTU, Prague, Czech Republic). Defended 19/11/2010. Sebastien´ LABBE´. Structure des pavages, droites discretes` 3D et combinatoire des mots. Advisors: V. Berthe´ & S. Brlek (Universite´ du Quebec,´ Canada). Defended 4/05/2012.

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Anna Chiara LAI. On expansions in non-integer base. Advisors: Ch. Frougny and P. Loreti (Univer- sita La Sapienza, Roma, Italy). Defended 09/03/2010.

Hoang-Thach NGUYEN. Reseaux de Petri stochastiques a forme produit. Advisor: J. Mairesse. De- fended 18/04/2012.

6.4.2 Thesis and habilitation reports

6.4.2.1 Reports for Habilitations a` Diriger les Recherches

V. Berthe.´ Reviewer for the Habilitation thesis of L. Fuchs, Fondements algebriques´ de la modelisation´ geom´ etrique´ , Universite´ de Strasbourg, 2010. C. Choffrut. Reviewer for the Docentship in Mathematics of J. Honkala, Turku University, Finland, 2007. Reviewer for the Habilitation thesis of D. Rossin, Analyse combinatoire de modeles` physiques et biologiques, Universite´ Paris Diderot-Paris 7, 2007. Reviewer for the Habilitation thesis of P.Q. Nguyen, Theorie´ et pratique de la Cryptanalyse a` clef publique, Ecole´ Normale Superieure´ de Paris, 2007. Ch. Frougny. Reviewer for the Habilitation thesis of L. Imbert, Arithmexotiques´ , Montpellier, 2008. J. Mairesse. Reviewer for the Habilitation thesis of J.-B. Yunes,` A` propos d’automates cellulaires suivi par Des fonctions Booleennes´ , Universite´ Paris Diderot-Paris 7, 2007. Reviewer for the Habilitation thesis of S. Haar, Law and partial order - Nonsequential behavior and probability in asynchronous sytems, Universite´ de Rennes 1, 2008. Reviewer for the Habilitation thesis of T. Bonald, Evaluation´ de performance de reseaux´ de donnees´ , Universite´ Pierre et Marie Curie-Paris 6, 2010. President of the committee for the Habilitation thesis of E. Jeandel, Propriet´ es´ structurelles et calculatoires des pavages, Universite´ de Marseille, 2011. J.-E.´ Pin. President of the committee for the Habilitation thesis of P.-C. Heam,´ Automates finis pour la fiabilite´ logicielle et l’analyse d’accessibilite´, Universite´ de Besançon, 2009. President of the committee for the Habilitation thesis of C. Nicaud, Analyse d’algorithmes et gen´ eration´ aleatoire´ en theorie´ des langages, Universite´ de Marne-la-Vallee,´ 2011. Reviewer for the Habilitation thesis of P. Habermehl, Contribution a` la verification´ de systemes` avec structures de donnees´ complexes a` l’aide d’automates, Universite´ Paris Diderot-Paris 7, 2009. Reviewer for the Habilitation thesis of T. Touili, Modelisation´ et Analyse d’Accessibilite´ des Pro- grammes Recursifs´ Concurrents, Universite´ Paris Diderot-Paris 7, 2009. Reviewer for the Habilitation thesis of M. Kunc , Implicit Language Equations, Brno University, Czech Republic, 2010. Reviewer for the Habilitation thesis of M. Rigo, Systemes` de numeration´ abstraits et combinatoire des mots, Universite´ Paris 11, 2010. J.-B. Yunes.` Reviewer for the Habilitation thesis of C. Prieur, Reseaux´ sociaux, algorithmes, identites´ , Universite´ Paris Diderot-Paris 7, 2012.

6.4.2.2 Thesis reports

V. Berthe.´ Reviewer for the PhD thesis of M. Said, Geom´ etrie´ multi-resolution´ des objets discrets bruites´ , Universite´ de Chambery,´ 2010. Reviewer for the PhD thesis of A. Blondin-Masse,´ A` l’intersection de la combinatoire des mots et de la geom´ etrie´ discrete` : palindromes, symetries´ et pavages, UQAM, Montreal,´ Canada, 2011.

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O. Carton. Reviewer for the PhD thesis of R. de Souza, Etude´ structurelle des transducteurs de norme bornee´ , ENST,´ 2008. Reviewer for the PhD thesis of B. Cagnard, Etude´ topologique de fonctions definissables´ par automate, Universite´ de Corse, 2008. Reviewer for the PhD thesis of S. Hassen, Synchronisation de grammaires de graphes, Universite´ de La Reunion,´ 2009. Reviewer for the PhD thesis of J. M. Sastre-Martinez, Algorithmes performants a` etats´ finis pour l’application de grammaires locales, Universite´ Paris Est, 2011. Reviewer for the PhD thesis of T. V. Duc, Des codes pour engendrer les langages de mots infinis, Universite´ de Nice, 2011. C. Choffrut. Reviewer for the PhD thesis of E. Czeizler, Intricacies of word equations, Turku Univer- sity, Finland, 2007. Reviewer for the Licentiate thesis of A. Saarela, A new proof of Hmelevski’s Theorem, Turku Uni- versity, Finland, 2009. Reviewer for the PhD thesis of J. Lin, Size constaint clustering, Milano University, Italy, 2012. Reviewer for the PhD thesis of P.-Y. Angrand, Contribution a` l’etude´ des expressions rationelles, et a` l’etude´ des systemes` d’enum´ eration´ abstraits, ENST,´ 2012. Ch. Frougny. Reviewer for the PhD thesis of N. Aubrun, Dynamique symbolique des systemes` 2D et des arbres infinis, Universite´ Paris Est, 2011. S. Grigorieff Reviewer for the PhD thesis of H. Zenil, Une approche experimentale´ a` la theorie´ algorithmique de la complexite´, Universite´ Paris 1 Pantheon-Sorbonne,´ 2011. J. Mairesse Reviewer for the PhD thesis of M.-A. Tran, Insensibilite´ dans les reseaux´ de files d’attente et applications au partage de ressources informatiques, Ecole´ Polytechnique, 2007. Reviewer for the PhD thesis of C. Holtzmann, Sous-groupe de petit indice des groupes de tresses et systemes` de reécriture´ , Universite´ de Bourgogne, 2008. Reviewer for the PhD thesis of J. Fromentin, Forme normale tournante des tresses, Universite´ de Caen, 2009. Reviewer for the PhD thesis of L. Boyer, Comportements typiques dans les automates cellulaires, Universite´ de Chambery,´ 2010. M. Picantin External Examiner for the PhD thesis of M. Cummings, Garside Groups and Enumeration of Partitions, Warwick university, UK, 2009. J.-E.´ Pin Reviewer for the PhD thesis of A. Costa, Profinite semigroups and symbolic dynamics, Porto university, Portugal, 2007. Reviewer for the PhD thesis of V. Bar´ any,´ Automatic Presentations of Infinite Structures, RWTH Aachen, Germany, 2007. Reviewer for the PhD thesis of R. Jungers, Infinite Matrix Products. From the joint spectral radius to combinatorics, Universite´ de Louvain la Neuve, Belgium, 2008. Reviewer for the PhD thesis of J. Otero Pombo, Robust Lexical Analysis, Vigo University, Spain, 2009. Reviewer for the PhD thesis of X. Allamigeon, Static analysis of memory manipulations by abstract interpretation Algorithmics of tropical polyhedra, and application to abstract interpretation, Ecole´ Polytechnique, 2009. Reviewer for the PhD thesis of A. Moura, Pseudovarieties: idempotent-generated semigroups and representations of DA, Porto university, Portugal, 2009. Reviewer for the PhD thesis of T. Place, Decidable Characterizations for Tree Logics, Ecole´ Nor- male Superieure´ de Cachan, 2010. Reviewer for the PhD thesis of S. Torunczyk,´ Languages of profinite words and the limitedness problem, Warsaw University, Poland, 2011.

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O. Serre Reviewer for the PhD thesis of A. Da Costa Lopes, Propriet´ es´ de jeux multi-agents, Ecole´ Normale Superieure´ de Cachan, 2011. W. Steiner Reviewer for the PhD thesis of C. Kalle, Expansions and Extensions, Universiteit Utrecht, Netherlands, 2009.

6.4.3 Teaching

6.4.3.1 University courses at M2R level

MPRI Theory of computations, L. Bienvenu and S. Perifel. [Link to the course webpage]. MPRI Mathematical Foundations of Automata Theory, O. Carton and J.-E.´ Pin. [Link to the course webpage]. MPRI Game theory techniques in computer science, O. Serre and W. Zielonka. [Link to the course webpage]. MPRI Modelisation´ par automates ﬁnis, C. Choffrut, T. Colcombet, Ch. Frougny and I. Klimann. [Link to the course webpage]. MPRI Cours de mise a` niveau en Probabilites,´ J. Mairesse (from 2005 to 2007). MPRI Dynamique et algorithmique des reseaux,´ J. Mairesse (from 2006 to 2009). CTU Prague Periodicity and ﬁniteness in non-standard numeration systems, Ch. Frougny, March 2011. TU Graz Automata, languages and numeration systems, Ch. Frougny, March 2012.

6.4.3.2 Special thematic programs and specialist courses

Research Schools

ALEA Journees´ ALEA, ecole´ thematique´ du CNRS. Marseille, 2007. J. Mairesse. ENS Lyon Research school on computability and complexity, Lyon, 2011. S. Perifel. ENS Lyon Research school on computability and complexity, Lyon, 2012. L. Bienvenu. EJCIM “Ecole Jeunes Chercheurs en Informatique Mathematique”,´ Rennes, 2012. Applications de systemes` dynamiques discrets, V. Berthe.´ EPIT “Ecole de Printemps d’Informatique Theorique”,´ Bordeaux, 2012. Automata with counters, T. Colcombet. EPIT “Ecole de Printemps d’Informatique Theorique”,´ Bordeaux, 2012. Proﬁnite approach to language theory, Spring School on Algorithmic Game Theory Ecole´ thematique´ du CNRS (GDR RO), Paris, 2012. Introduction to game theory, O. Serre.

Other

Rencontres algorithmique et programmation “Jeux concurrents”, CIRM, 2009, O. Serre. Univ. Madagascar Ecole´ de Combinatoire et Algorithmique de Madagascar, Antananarivo, 2011. Cours de programmation, J.-B. Yunes.` ISN Lectures for high school teachers for the forthcoming speciality “Informatique et Science du Numerique”´ (ISN), 2012. L. Bienvenu and J.-B. Yunes.`

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6.4.3.3 Board of examiners

ENS´ Paris J. Mairesse was an examiner in the first year selection process of Ecole´ Normale Superieure´ de Paris (“Informatique Fondamentale”) until 2007. ENS´ Paris O. Carton was an examiner in the first year selection process of Ecole´ Normale Superieure´ de Paris (“TIPE Option informatique”) until 2007. ENS´ Paris O. Serre was an examiner in the first year selection process of Ecole´ Normale Superieure´ de Paris (“Informatique Fondamentale”) from 2008 to 2010. ENS´ Cachan O. Serre is an examiner in the third year selection process of Ecole´ Normale Superieure´ de Cachan (written and/or oral examination) since 2009. ENS´ Paris O. Serre is an examiner in the first year selection process of Ecole´ Normale Superieure´ de Paris (“TIPE Option informatique”) since 2011.

6.4.3.4 Popularization

Mathematic Park I. Markovici and A. Taveneaux are members of the steering committee of Math- ematic Park, a seminar for high school and undergraduate students and their teachers. See http://www.ihp.fr/fr/seminaire/mathematic-park. International Mathematical Olympiad Antoine Taveneaux is one the coaches of the France team for the International Mathematical Olympiad. MATh.en.JEANS A. Taveneaux is a member of the executive board of MATh.en.JEANS. He is also taking care of two high schools (College` Camille Claudel and College` du Moulin des Pres).´ Feteˆ de la Science Numerous talks from the members of the group. High schools Several talks by J.-B. Yunes.` College` Belgique “Arithmetique,´ automates et geom´ etrie´ discrete;` Fractions continues en geom´ etrie´ discrete` arithmetique”,´ 2011, V. Berthe.´ La Recherche “Un ordinateur pourra-t-il repondre´ a` cette question ?”, La recherche, 449 (01/2011), T. Colcombet. Cite´ des Sciences et de l’Industrie Talk on cryptography and complexity, 2011, S. Perifel. √ Images des mathematiques´ “Nombres et representations.´ Les decimales´ de 2 sont-elles aleatoires?”,´ 2011, V. Berthe.´ Movies J. Mairesse was the scientiﬁc advisor for the movie “Le modele` Turing” produced by CNRS Images in 2012, and on the same topic he took part to the “Researchers’ Film Festival”. See http://www.ﬁlmdechercheur.eu. Mathematic Park “Fractions continues et traces´ de droites”, 2012, V. Berthe.´

6.4.4 Prices and distinctions

• CNRS Bronze medal awarded to T. Colcombet in 2011. • Prize and subvention of the Simone and Cina del Duca Foundation awarded by the French Academy of Science to J. Mairesse in 2009. • Election of J.-E.´ Pin to the Academia Europeae. • Best paper awards in ICALP’08 for [GGP08]. • Best paper awards in ICALP’11 for [CCP11]. • Best paper awards in Int. Conf. on Petri Nets’11 for [HMN11].

197 CHAPTER 6. APPENDIX: AUTOMATA AND APPLICATIONS

198 Partie V

Equipe Combinatoire

199

Chapitre 1

Rapport scientiﬁque : Combinatoire

1.1 Thematique´ gen´ erale´ et principaux objectifs

1.1.1 Constitution de l’equipe´

L’equipe´ combinatoire du LIAFA a et´ e´ creée´ en Janvier 2011. Elle est formee´ de huit permanents : – Guillaume Chapuy (CR) – Sylvie Corteel (DR) – Enrica Duchi (MdC) – Jeremy Lovejoy (CR) – Roberto Mantaci (MdC - HDR) – Anne Micheli (MdC) – Dominique Poulalhon (MdC) – Vlady Ravelomanana (Pr) Notons que Dominique Poulalhon (MdC) est en detachement´ au CNRS de 2009 a` 2013 au LIX et sera de retour en Juin 2013. La combinatoire est un theme` historique et important du LIAFA. Daniel Krob (DR) et Michel Morvan (Pr) ont et´ e´ les piliers de la thematique´ jusqu’a` leur depart´ aux debuts´ des annees´ 2000. Dominique Rossin (CR) a ensuite pris la direction de l’equipe´ puis a quitte´ le LIAFA pour le LIX en 2010. En 2007, la “partie combinatoire” de l’equipe´ Algorithmique et Combinatoire etait´ formee´ de E. Duchi (MdC, arrivee´ en 2007), J. Lovejoy (CR, arrive´ en 2007), A. Micheli (MdC depuis 2002), R. Mantaci (MdC depuis 1992), D. Poulalhon (MdC depuis 2003), D. Rossin (CR) et des doctorants M. Bouvel et O. Mallet. Dans la periode´ 2007-2012, le groupe a egalement´ inclus temporairement O. Bodini (del´ egation´ CNRS), F. Disanto (doctorant en cotutelle), JS. Kim (postdoctorant), P. Nadeau (ATER) et V. Pilaud (ATER). Mais c’est depuis l’arrivee´ de Vlady Ravelomanana en tant que professeur en 2009 et de Sylvie Corteel et Guillaume Chapuy en 2010 que le groupe a vraiment pu se former, avec un recentrage des thematiques´ autour de la combinatoire enum´ erative´ et de l’analyse d’algorithmes. Les debuts´ de l’equipe´ ont d’abord et´ e´ non officiels. Nous avons commence´ par creer´ un seminaire´ hebdomadaire en Mars 2010 organise´ par Sylvie Corteel et Vlady Ravemolamanana. Puis en Septembre 2010, nous avons creé´ un groupe de lecture organise´ par Guillaume Chapuy. C’est suite a` cette emulation´ scientifique que la direction du LIAFA a decid´ e´ de la creation´ de l’equipe´ combinatoire. L’equipe´ combinatoire est une equipe´ ancree´ dans les thematiques´ de l’informatique theorique.´ Nos specialit´ es´ sont la combinatoire enum´ erative´ et l’analyse d’algorithmes. De plus, nous sommes une equipe´ ouverte a` l’interdisciplinarite.´ Ainsi Jeremy Lovejoy est un chercheur qui vient de la section 01 (Mathematiques)´ et travaille a` l’interface de la combinatoire et de la theorie´ des nombres. Nous

201 CHAPITRE 1. RAPPORT SCIENTIFIQUE : COMBINATOIRE nous interessons´ aussi aux interactions entre la combinatoire algebrique,´ la physique theorique´ et les probabilites.´ Pendant l’annee´ 2011-2012, nous accueillons Jer´ emie´ Bouttier (CEA Saclay en del´ egation).´ La specialit´ e´ de Jer´ emie´ est la physique combinatoire et il est maintenant membre associe´ de l’equipe.´ Notre autre membre associe´ est Philippe Biane (DR CNRS) qui est probabiliste. La thematique´ combinatoire a egalement´ vu une evolution´ pour l’encadrement de doctorants. Ainsi dans la periode´ 2007-2012, trois theses` ont et´ e´ soutenues : Olivier Mallet (2008 sous la direction de Jeremy Lovejoy), Mathilde Bouvel (2009 sous la direction de Dominique Rossin) et Filippo Disanto (2010 en cotutelle sous la direction d’Enrica Duchi et Simone Rinaldi (Universite´ de Sienne)). Actuellement cinq theses` sont en preparation´ : – 2009- : Adeline Pierrot (direction de D. Rossin) AMN – 2010- : Sandrine Dasse-Hartaut (direction S. Corteel) AM Paris Diderot – 2011- : Robin Langer (direction S. Corteel) ANR IComb – 2011- : Elie de Panaﬁeu (direction V. Ravelomanana) AMN – 2011- : Antoine Crouzet (direction V. Ravelomanana) Prof en lycee´

Au LIAFA, nous avons des interactions avec plusieurs equipes.´ Les interactions les plus naturelles sont avec l’equipe´ automates et en particulier les personnes qui s’interessent´ aux systemes` dynamiques discrets. Ainsi trois projets de recherche ont et´ e´ menes´ conjointement avec des membres des deux equipes´ sur la periode´ 2007-2012 (Mairesse-Micheli-Poulalhon, Mantaci-Yunes` et Chapuy-Klimann). Mais d’autres interactions voient le jour naturellement. Ainsi en Juin 2012 Eugene` Asarin (Veriﬁcation)´ a fait un expose´ au seminaire´ sur ses travaux sur les series´ gen´ eratrices´ liees´ aux automates temporises.´ Jean-Eric Pin (Automates) sera orateur en Octobre 2012. Nous etudierons´ les interactions possibles avec les gens autour de Paul-Andre´ Mellies` a` PPS. Nous avons aussi des interactions naturelles avec le departement´ de mathematiques´ de l’Universite´ Paris-Diderot avec des chercheurs du LPMA (S. Pech´ e,´ J. Salez) et de l’IMJ (B. Keller, M. Vergne). Nous avons des collaborations avec des chercheurs et enseignants-chercheurs de Paris 6, Paris 13, Marne la Vallee,´ Orsay, Polytechnique, Marseille, Bordeaux et Lyon. Notre positionnement geographique´ central fait que plusieurs chercheurs franciliens participent a` nos activites´ scientiﬁques et ceci amenent` beaucoup de discussions et de collaborations. De plus, notre equipe´ est naturellement internationale puisque certains de nos membres viennent de Madagascar, d’Italie et des Etats-Unis. Memeˆ si nos collaborations sont principalement avec ces pays, nous collaborons aussi avec des chercheurs d’Espagne, du Canada et de l’Irlande. Les themes` de recherche de l’equipe´ se declinent´ autour de plusieurs axes que nous presenterons´ ci- dessous. Neanmoins´ tous les membres participent a` plusieurs axes et cela fait notre force. Nous pouvons ainsi attaquer les problemes` avec les techniques appropriees´ et collaborer activement. – Combinatoire enum´ erative´ et bijective (B, Ch, Co, D, L, Ma, Mi, P, Ro) – Combinatoire algebrique´ (Ch, Co) – Combinatoire analytique (Co, Ra) – Combinatoire des cartes planaires et de genre superieur´ (B, Ch, Mi, P) – Structures aleatoires´ (Ch, Ra) – Algorithmes de gen´ eration´ aleatoire´ et exhaustive (D, Ma, P) – Algorithmes combinatoires (Mi, P, Ro) –S eries´ hypergeom´ etriques´ (Co, L)

202 CHAPITRE 1. RAPPORT SCIENTIFIQUE : COMBINATOIRE

(Code : B=Bouttier, Ch=Chapuy, Co=Corteel, D=Duchi, L=Lovejoy, M=Mantaci, Mi=Micheli, P=Poulalhon, Ra=Ravelomanana, Ro=Rossin) Dans la partie suivante, nous mettrons en avant quelques resultats´ signiﬁcatifs dans la plupart des themes` present´ es´ ci-dessous.

1.2 Exemples de resultats´ signiﬁcatifs

C. Alfes (Cologne, Allemagne), K. Bringmann (Cologne, Allemagne), J. Lovejoy (LIAFA) et R. Osburn (UCD, Irlande) ; q-series´ et fonctions Mock Theta Dans une serie´ d’articles en collaboration avec C. Alfes, K. Bringmann, et R. Osburn, nous etudions´ la mock-modularite´ des series´ basiques hypergeometriques´ (q-series).´ Nous trouvons des q-series´ qui sont a` la fois des formes mock modulaires de poids 3/2, a` la fois des eigenforms pour les operateurs´ de Hecke, et a` la fois des fonctions gen´ eratrices´ pour les nombres de classes de Hurwitz. Nous nous laissons guider par la combinatoire. Par exemple, notre premier exemple est la fonction gen´ eratrice´ pour les surpartitions ponder´ ees´ de la parite´ du rang de Dyson. Nous trouvons egalement´ des fonctions mock theta,ˆ dont certaines familles inﬁnies construites a` partir de la chaˆıne de Bailey. Certains resultats´ ont et´ e´ publies´ dans Math. Proc. Cambridge Phil. Soc. et les autres sont soumis a` un journal international (voir arXiv :1008.3474 et arXiv :1201.6194).

M. Albenque (LIX) et J. Bouttier (LIAFA) ; Cartes et constellations. Dans l’article ”Constellations and multicontinued fractions” co-ecrit´ avec M. Albenque (LIX), nous developpons´ une extension de la theorie´ combinatoire des fractions continues introduite par Flajolet. L’objectif est de prouver une formule conjecturee´ par P. Di Francesco (CEA) reliant combinatoire enum´ erative´ (comptage d’une fa- mille de cartes planaires appelees´ constellations) et systemes` integrables´ (equations´ KP, originellement introduites en physique ondulatoire). Notre premier resultat´ est la preuve, par une methode´ bijective el´ ementaire,´ de la formule dans le cas des ”triangulations euleriennes”.´ Nous obtenons egalement´ des expressions determinantales´ dans le cas gen´ eral.´ Ce travail sera present´ e´ a` FPSAC2012 (voir arXiv :1112.6379).

M. Bousquet-Melou´ (LABRI), G. Chapuy (LIAFA) et L.F. Preville-Ratelle´ (Montreal)´ ; Demonstration´ des conjectures de Franc¸ois Bergeron sur les intervalles de Tamari. Il s’agit de la realisation´ d’un projet de recherche ambitieux demarr´ e´ en 2010 avec M. Bousquet-Melou´ (Bordeaux) and L.-F. Preville-´ Ratelle (Montreal).´ Ces conjectures trouvent leur origine dans la theorie´ tres` active outre-Atlantique des algebres` coinvariantes, et dans les gen´ eralisations´ de la fameuse “conjecture n!” demontr´ ee´ par Haiman en 2002. Elles concernent l’enum´ eratio´ n d’objets appeles´ intervalles de Tamari, et plus gen´ eralement´ l’etude´ ﬁne d’une representation´ associee´ du groupe symetrique.´ La resolution´ du probleme` repose sur l’application inattendue de techniques trouvant leur origine dans le domaine de l’enum´ eration´ de cartes combinatoires, ce qui suggere` un lien fructueux entre les deux domaines et d’importantes possibilites´ d’ouvertures et de developpements´ futurs. Ce travail sera present´ e´ a` FPSAC2012 (voir arXiv :1109.2398 et arXiv :1202.5925 ).

S. Corteel (LIAFA) et L. Williams (Berkeley) ; Combinatoire des moments des polynomesˆ orthogonaux. Sylvie Corteel (LIAFA) et Lauren Williams (Berkeley) ont recemment´ propose´ une interpretation´ combinatoire des moments des polynomesˆ d’Askey Wilson. Ces travaux sont principalement combinatoires, bien que ces moments ne soient ni des entiers, ni a` coefﬁcients positifs. C’est grace a` la physique statistique et au modele` d’exclusion, que ce probleme a pu etreˆ resolu. Ces travaux permettent de boucler un chantier engage´ par P. Flajolet en 1980 et mis sous forme de theorie´ par X. Viennot dans les annees´ 80 sur la combinatoire des fractions continues et des moments des polynomesˆ orthogonaux.

203 CHAPITRE 1. RAPPORT SCIENTIFIQUE : COMBINATOIRE

En effet les polynomesˆ d’Askey Wilson sont les polynomesˆ orthogonaux les plus gen´ eraux.´ Ces travaux sont publies´ dans Duke Mathematical Journal (2011) et Transactions of the AMS (2012).

H. Daude´ (Marseille), V. Ravelomanana (LIAFA) ; Analyse d’algorithmes et transition de phase Nous considerons´ le probleme` de satisfiabilite´ des formules 2− XOR ou` chaque instance est une conjonction d’equations´ booleennes´ (clauses) de la forme x ⊕ y = 0 ou x ⊕ y = 1. Une formule de m clauses impliquant n variables booleennes´ est constituee´ de m clauses choisies aleatoirement´ uniformement´ n(n−1) parmi toutes les m clauses possibles. Quand n tend vers l’infini et m approche n/2, la formule est sujette a` une transition de phase : la probabilite´ de satisfiabilite´ decro´ ˆıt vers zero.´ En utilisant une approche combinatoire et analytique, nous proposons une description precise´ des regions´ sous-critique et critique de la transition de phase des formules 2−XOR. Ce travail est publie´ dans Algorithmica (2011).

F. Disanto (Sienna), E. Duchi (LIAFA), S. Rinaldi (Sienna), G. Schaeffer (LIX) ; Sur les permutations avec un nombre fixe´ de points interieurs.´ Nous definissons´ les records d’une permutation σ comme ses minima (resp. maxima) de gauche a` droite et de droite a` gauche. Un point (i, j) avec j = σ(i) est un point interieur´ de la permutation si et seulement si ce n’est pas un record. Les permutations n’ayant pas de points interieurs´ sont appellees´ carrees.´ On considere` l’enum´ eration´ des permutations avec un nombre fixe´ de points interieurs.´ En etendant´ une construction obtenue avec D. Poulalhon pour l’enum´ eration´ des permutations carrees,´ on arrive a` montrer que la serie´ gen´ eratrice´ des permutations avec un nombre fixe´ i de points interieurs´ est algebrique´ de degre´ 2. Plus precisement´ elle est rationelle en la serie´ gen´ eratrice´ de Catalan. Notre approche est constructive et permet aussi d’enum´ erer´ les permutations selon leurs differents´ types de records. Ce travail a et´ e´ present´ e´ a` EuroComb 2011.

J. Mairesse (LIAFA), A. Micheli (LIAFA) et Dominique Poulalhon (LIX) ; Algorithme de minimisation de tresses a` 4 brins. La theorie´ des tresses, sous-ensemble de la theorie´ des nœuds, est liee´ a` des problemes` algebriques,´ ainsi que des problemes` de mecanique´ statistique. Le probleme` de l’isotopie est un probleme` central en theorie´ des nœuds tres` difficile dans le cas gen´ eral´ qui devient plus facile (mais non trivial) dans le cas des tresses graceˆ a` la structure de groupe de l’ensemble. Le probleme` consiste a` determiner´ si deux diagrammes de tresse (ou deux mots de tresse) definissent´ la memeˆ tresse. Un autre probleme` en theorie´ des tresses consiste a` se demander si etant´ donne´ un mot de tresse, il existe un representant´ de la memeˆ tresse plus court en nombre de gen´ erateurs.´ Ce probleme,` qui ne semble pas tres` eloign´ e´ du probleme` de l’isotopie de deux mots de tresse, est pourtant un probleme` NP-complet. Ce qui n’interdit pas l’existence d’un algorithme polynomial a` nombre de brins fixes.´ C’est le cas lorsque le nombre de brins est egal´ a` 3, mais, avant nos travaux, aucun algorithme polynomial n’etait´ connu pour les tresses avec un plus grand nombre de brins : le seul algorithme connu, exponentiel, ne peut repondre´ a` cette question pour 4 brins que si le mot de tresse est de longueur inferieure´ ou egale´ a` 13. Depuis 3 ans, nous travaillons sur ce probleme` de minimisation dans le cas de 4 brins, pour lequel nous avons decrit´ un algorithme cubique ; la preuve de la correction de l’algorithme est en cours de redaction.´

R. Mantaci (LIAFA), P. Massazza (Universite´ de l’Insubria, Italie) et J-B. Yunes (LIAFA) ; Algorithmes de gen´ eration´ exhaustive. R. Mantaci s’est recemment´ interess´ e´ a` la gen´ eration´ exhaustive de structures combinatoires au moyen d’algorithmes CAT (constant amortized time). Dans les travaux communs avec Paolo Massazza (Universite´ de l’Insubria, Varese, Italie) et avec Jean-Baptiste Yunes (LIAFA) l’approche choisie est celle de trouver un ordre lineaire´ qui etend´ l’ordre partiel deﬁni´ naturellement sur les posets que ces objets forment. Ceci a permis la gen´ eration´ de certaines familles de partitions lineaires,´ telles que les conﬁgurations accessibles des systemes` dynamiques discrets SPM (Piles de sable) et IPM (pile de glace) aussi bien dans leur variante unilaterale´ que bilaterale,´ de l’ensemble de toutes les partitions planes d’un entier n ou de certaines familles de polyominos tels que le polyomi-

204 CHAPITRE 1. RAPPORT SCIENTIFIQUE : COMBINATOIRE nos parallelogramme.´ Tout recemment,´ une nouvelle approche a et´ e´ utilise´ dans les travaux en cours avec Wenjie Fang (etudiant´ M2 en stage au LIAFA), permettant d’obtenir des algorithmes CAT pour la gen´ eration´ des piles de sable et de glace. Cette approche est basee´ sur des propriet´ es´ combinatoires des objets, plutotˆ que sur la dynamique du systeme.`

1.3 Animation scientiﬁque, rayonnement, prix et recompenses´

La conference´ la plus importante pour notre equipe´ est la conference´ FPSAC : Formal Po- wer Series and Algebraic Combinatorics. Nous participons activement a` cette conference´ par des soumissions chaque annee.´ Par exemple, Guillaume Chapuy fait deux exposes´ cette annee´ (avec des coauteurs differents)´ et Adeline Pierrot et Robin Langer presentent´ un poster. Nous sommes aussi actifs dans l’organisation de cette conference.´ Jeremy Lovejoy a fait partie du comite´ de programme en 2008 et Sylvie Corteel en 2006, 2010 et 2012. Toute l’equipe´ parti- cipera a` l’organisation de cette conference´ en 2013 qui aura lieu a` l’Universite´ Paris-Diderot http://www.liafa.univ-paris-diderot.fr/fpsac13. Les autres conferences´ importantes auxquelles nous participons sont SODA, STACS et AofA. Vlady Ravelomanana a present´ e´ un papier a` SODA cette annee´ par exemple. Nous organisons aussi des conferences´ et ateliers ponctuels : en 2011 un atelier sur les piles de sable organises´ par Roberto Mantaci et Jean-Baptiste Yunes` (equipe´ automates) http://www.liafa.jussieu.fr/ yunes/WSPM/WSPM/Main.html et en 2012 une conference´ internationale sur les series´ hypergeom´ etriques´ organisee´ par Jeremy Lovejoy et Tanguy Rivoal (Lyon) http://www.liafa.jussieu.fr/ lovejoy/hypergeometric.html. Au niveau national, nous participons fortement au GDR-IM et en particulier aux groupes de travail ALEA et Combinatoire algebrique.´ A` peu pres` toute l’equipe´ se deplace´ au CIRM pour les journees´ ALEA en Mars chaque annee.´ Anne Micheli et Dominique Poulalhon ont organise´ les journees´ ALEA 2009 en collaboration avec Jean Mairesse de l’equipe´ automates (avec un financement de l’ANR GAMMA). L’ANR IComb a participe´ au financement des journees´ ALEA 2012. Au niveau francilien, nous participons activement au rapprochement de la communaute´ francilienne par l’intermediaire´ du seminaire´ de combinatoire Philippe Flajolet. Ce seminaire´ bimestriel a lieu a` l’Institut Henri Poincare.´ Il a et´ e´ creé´ par Sylvie Corteel et Michele` Soria sous l’impul- sion de Philippe Flajolet en Octobre 2010. Il propose a` chaque seance´ trois seminaires´ de chercheurs confirmes´ et en gen´ eral´ les thematiques´ sont diverses : combinatoire enum´ erative,´ combinatoire analytique, analyse d’algorithmes, combinatoire algebrique,´ physique combinatoire. Le but de ce seminaire´ est de rassembler la communaute´ francilienne, mais des chercheurs provinciaux de Bordeaux, Caen, Calais, Rouen et Lyon viennent aussi reguli´ erement.` Page web du seminaire´ : http://www-apr.lip6.fr/sem-comb-anal-enum.html. Bien que relativement jeune, l’equipe´ a deja´ obtenu quelques recompenses.´ Guillaume Chapuy a obtenu le prix du meilleur article etudiant´ a` la conference´ FPSAC 2009 et le prix de these` de l’ecole´ polytechnique en 2010 avant d’etreˆ recrute´ au CNRS. Sylvie Corteel a obtenu un bon classement (dans les 400 premiers sur plus de 9000) a` l’ERC starting grant en 2008 et a ainsi obtenu une ANR Jeune Chercheur. Jeremy Lovejoy a obtenu aussi un bon classement a` l’ERC starting grant en 2009 mais l’ANR n’a plus souhaite´ finance´ les jeunes bien classes´ a` l’ERC.

1.4 Fonctionnement interne

Le seminaire´ hebdomadaire de combinatoire, commence´ en Mars 2010, est organise´ par S. Corteel et V. Ravelomanana. Le groupe de lecture hebdomadaire, commence´ en Septembre 2010, est organise´ par G. Chapuy. L’equipe´ a et´ e´ officialisee´ en Janvier 2011. Pour les credits´ obtenus, la periode´ prec´ edente´ a et´ e´ tres` ben´ efique.´ S. Corteel et J. Lovejoy sont finances´ par l’ANR JCJC IComb (2008-2013) obtenu suite a` un bon classement a` l’ERC starting grant 2008.

205 CHAPITRE 1. RAPPORT SCIENTIFIQUE : COMBINATOIRE

Cette ANR finance aussi la plupart des activites´ de l’equipe´ (stages, missions, seminaires,´ organisation de colloque). Plusieurs membres de l’equipe´ participent aussi a` l’ANR blanc Magnum (2010-2014), en particulier V. Ravelomanana et A. Micheli. Quelques missions ont aussi et´ e´ payees´ par le laboratoire et l’ERC starting grant Explore Maps (G. Schaeffer LIX). Nous venons egalement´ d’obtenir une ANR JCJC portee´ par G. Chapuy. Les professeurs invites´ par l’Universite´ Paris-Diderot dans l’equipe´ sont : – 2011 : R. Osburn (UCD, Irlande) collaboration avec J. Lovejoy – 2012 : O. Bernardi (MIT, USA) collaboration avec G. Chapuy – 2013 : A. Rechnitzer (UCB, Canada) collaboration avec S. Corteel – 2013 : S. Rinaldi (Sienne, Italie) collaboration avec E. Duchi Notre principal source pour le recrutement de doctorants est le MPRI, graceˆ aux deux cours auxquels nous participons : C2-10 et C2-15. Mais nous avons aussi recrute´ une australienne sur un financement ANR et un professeur de lycee.´ Pour les post-doctorants, nous avons recrute´ J.S. Kim sur un financement ANR et nous avons choisi ensemble qui soutenir pour la FSMP (2012 : A. Morales (MIT) pour collaborer avec G. Chapuy). Malheureusement, l’offre a et´ e´ faite tard et notre candidat avait dej´ a` accepte´ un autre poste. Il n’y a pas eu de poste de Maˆıtre de Conferences´ en combinatoire a` l’Universite´ Paris Diderot sur la periode.´ Nous avons soutenu de tres` bons candidats CR pour les concours CNRS (V. Pilaud, A. Sportiello et J. Salez). Ils ont tous et´ e´ classes.´ Sportiello a et´ e´ recrute´ CR1 et nomme´ au LIPN, Pilaud a et´ e´ recrute´ CR2 en section 01 et nomme´ au LIX et J. Salez a et´ e´ recrute´ maˆıtre de conferences´ en math a` Paris-Diderot.

206 Chapitre 2

Fiche resum´ e´ : Combinatoire

Intitule´ de l’unite´ : LIAFA, UMR 7089 Nom du Directeur de l’unite´ : Pierre Fraigniaud Nom du responsable de l’equipe´ : Sylvie Corteel

2.1 Effectifs

L’equipe´ combinatoire a et´ e´ creée´ en Janvier 2011. Elle est formee´ de huit permanents : – Guillaume Chapuy (CR) – Sylvie Corteel (DR) – Enrica Duchi (MdC) – Jeremy Lovejoy (CR) – Roberto Mantaci (MdC - HDR) – Anne Micheli (MdC) – Dominique Poulalhon (MdC) en del´ egation´ au LIX – Vlady Ravelomanana (Pr) et de cinq doctorants : – 2009- : Adeline Pierrot (direction de D. Rossin) AMN – 2010- : Sandrine Dasse-Hartaut (direction S. Corteel) AM – 2011- : Robin Langer (direction S. Corteel) ANR IComb – 2011- : Elie de Panafieu (direction V. Ravelomanana) AMN – 2011- : Antoine Crouzet (direction V. Ravelomanana) Prof en lycee´ 2.2 Production scientifique

1. E. Duchi a obtenu en collaboration avec D. Poulalhon et G. Schaeffer une preuve bijective de la formule d’Hurwitz. 2. A. Micheli a obtenu en collaboration avec D. Poulalhon et J. Mairesse un algorithme de minimisation de tresses a` quatre brins. 3. G. Chapuy a obtenu avec V. Feray´ et E. Fusy un modele` d’arbres pour les cartes unicellulaires. 4. J. Lovejoy a obtenu avec K. Bringmann un lien entre surpartitions et nombres de classe. 5. V. Ravelomanana a obtenu avec H. Daude´ des resultats´ de transition de phase pour Random 2- XORSAT.

207 CHAPITRE 2. FICHE RESUM´ E´ : COMBINATOIRE

2.3 Bilan quantitatif

Cinq doctorants en Juin 2012. Deux nouveaux a` partir de Septembre 2012. Trois candidats CR (V. Pilaud, J. Salez et A. Sportiello) classes´ en 2011 et 2012 mais pas affectes´ dans l’equipe.´ Recrutement de G. Chapuy (CR CNRS), V. Ravelomanana (Pr P7) et promotion de S. Corteel (DR CNRS). Production : 61 articles journaux, 21 conferences´ avec actes

2.3.1 Publications

1. S. Ahlgren, K. Bringmann, J. Lovejoy. `-adic properties of smallest parts functions ?. Adv. Math. 228.1 (2011), pp. 629-645. 2. G. Borot, J. Bouttier, E. Guitter. A recursive approach to the O(n) model on random maps via nested loops. J. Phys. A : Math. Theor. 45.045002 (2012). 3. S. Corteel, L. K. Williams. Tableaux combinatorics for the asymmetric exclusion process and Askey-Wilson polynomials. Duke Math. J. 159.3 (2011), pp. 385 ?415. 4. M. Bousquet-Melou,´ G. Chapuy, Louis-Franc¸ois Preville-Ratelle.´ The representation of the symmetric group on m-Tamari intervals. In : Proceedings of the 24th International Conference on Formal Power Series and Algebraic Combinatorics. Nagoya, Japan, 2012. 5. H. Daude,´ C. Martinez, V. Rasendrahasina, V. Ravelomanana. The MAX-CUT of sparse random graphs. In : SODA. 2012, pp. 265-271.

2.3.2 Rayonnement

– Organisation d’un groupe de lecture et d’un seminaire´ hebdomadaire pour l’equipe´ et plusieurs chercheurs franciliens de Marne la Vallee,´ Polytechnique et le CEA Saclay (Guillaume Chapuy, Sylvie Corteel et Vlady Ravelomanana) – Canadam 2009 : Conference´ pleni´ ere` (S. Corteel) – 2012 : Organisation de la conference´ “Hypergeometric series and their generalizations in algebra, geometry, number theory and physics” (Jeremy Lovejoy) – 2010-2014 : ANR Blanc Magnum (Paris 6, Paris 7, Paris 13) – 2009 : Prix du meilleur papier etudiant´ a` FPSAC 2009 (Guillaume Chapuy)

2.3.3 Actions de formation

L’equipe´ participe a` un cours de combinatoire au niveau Licence et a` deux cours de niveau 2 du MPRI : analyse d’algorithmes et aspects algorithmiques de la combinatoire. Le Master Pro proposera au prochain quinquennal un cours en analyse d’algorithmes.

208 Chapitre 3

Executive Summary : Combinatorics

Laboratory’s name : LIAFA, UMR 7089 Laboratory director’s name : Pierre Fraigniaud Team leader’s name : Sylvie Corteel

3.1 Members

The team was created in Januray 2011. We have eight permanent members : – Guillaume Chapuy (CR) – Sylvie Corteel (DR) – Enrica Duchi (MdC) – Jeremy Lovejoy (CR) – Roberto Mantaci (MdC - HDR) – Anne Micheli (MdC) – Dominique Poulalhon (MdC) en del´ egation´ au LIX – Vlady Ravelomanana (Pr) 5 graduate students : – 2009- : Adeline Pierrot (supervised by D. Rossin) AMN – 2010- : Sandrine Dasse-Hartaut (supervised by S. Corteel) AM – 2011- : Robin Langer (supervised by S. Corteel) ANR IComb – 2011- : Elie de Panaﬁeu (supervised by V. Ravelomanana) AMN – 2011- : Antoine Crouzet (supervised by V. Ravelomanana) Hight school teacher

3.2 Scientiﬁc outcomes

1. E. Duchi gave a bijective proof of Hurwitz formula with D. Poulalhon and G. Schaeffer. 2. A. Micheli has obtained a minimization algorithm for 4 braids with D. Poulalhon and J. Mairesse. 3. G. Chapuy proposed with V. Feray´ and E. Fusy a tree model for unicellular maps. 4. J. Lovejoy in collaboration with K. Bringmann proposed a link between overpartitions and class numbers. 5. V. Ravelomanana obtained with H. Daude´ some results on phase transition for Random 2- XORSAT.

209 CHAPITRE 3. EXECUTIVE SUMMARY : COMBINATORICS

3.3 Quantitative assessment

Five PhD students in 2012. Two new from September 2012 (supervised by J. Lovejoy and G. Chapuy). Three candidates for CNRS were ranked and/or hired (V. Pilaud, J. Salez and A. Sportiello) in 2011 and 2012. Hiring : G. Chapuy (CR CNRS), V. Ravelomanana (Pr P7) and promotion of S. Corteel (DR CNRS). Production : 61 journal papers, 21 conference papers

3.3.1 Publications

3.3.2 Software, patents, reports, etc. Habilitation a` Diriger des Recherches : Sylvie Corteel (Mai 2010)

3.3.3 Inﬂuence of the team

– Reading group and seminar organized for the team members and several conﬁrmed researchers from Marne la Vallee,´ Polytechnique end CEA Saclay (Organizers : Guillaume Chapuy, Sylvie Corteel et Vlady Ravelomanana) – Canadam 2009 : Plenary speaker (S. Corteel) – Editorial work : editorial committee of Annals of Combinatorics – 2012 : Organisation of the conference “Hypergeometric series and their generalizations in algebra, geometry, number theory and physics” (Jeremy Lovejoy) at IHP – 2010-2014 : ANR Blanc Magnum (Paris 6, Paris 7, Paris 13) – 2009 : Best student paper, FPSAC 2009 (Guillaume Chapuy)

3.3.4 Teaching

The team participates in one undergraduate class at the Universite´ Paris-Diderot, sophomore level, in combinatorics and two graduate classes at the MPRI : analysis of algorithms and algorithmic aspects of combinatorics. The “Master pro” at the Universite´ Paris-Diderot will propose an analysis of algorithms class from 2013.

210 Chapitre 4

Projet scientiﬁque : Combinatoire

4.1 Objectifs scientiﬁques

4.1.1 Auto-evaluation´

L’equipe´ combinatoire est jeune et est en cours de structuration. Les theme` centraux de l’equipe´ sont la combinatoire enum´ erative´ et l’analyse d’algorithmes ; mais de nombreux autres themes` sont presents´ dans l’equipe.´ Pour les annees´ a` venir, notre objectif est de proﬁter au maximum de nos forces presentes´ pour former un groupe fort. Nous souhaitons aussi nous renforcer par notre politique de membres associes´ et nos interactions avec, entre autres, nos partenaires franciliens mais aussi par l’attraction de nouveaux membres (doctorants, post-doctorants et permanents. Ainsi deux nouveaux doctorants arrive- ront en 2012 sous la direction de G. Chapuy et J. Lovejoy. Des post-doctorants seront embauches´ sur l’ANR Cartaplus. Nous utiliserons aussi les possibilites´ de la Fondation Sciences Mathematiques´ de Pa- ris, de la Mairie de Paris, du DIM mathematiques,´ de l’Universite´ Paris-Diderot et des projets inter-Idex pour le recrutement de non-permanents et l’invitation de chercheurs etrangers.´ Nous continuerons aussi d’inciter les jeunes docteurs brillants a` candidater dans notre equipe.´ Nous resumons´ l’auto-evaluation´ de l’equipe´ dans la ﬁgure 4.1.

4.1.2 Evolution par rapport a` la periode´ prec´ edente´

En 2007, la partie “combinatoire” de l’equipe´ Algorithmique et Combinatoire etait´ assez affaiblie suite au depart´ de Daniel Krob et de Michel Morvan. De plus, quasiment tous les recrutements et les mutations avaient et´ e´ effectue´ dans les thematiques´ de l’algorithmique des graphes, de l’algorithmique distribuee´ et des reseaux.´ Suite au recrutement de V. Ravelomanana (Pr P7), puis a` l’arrivee´ de S. Corteel (CNRS) et au recrutement de G. Chapuy (CNRS), nous avons atteint une masse critique et forme´ une equipe.´ Notre grande evolution´ est en matiere` de doctorants. En effet il y a eu deux theses` (plus une en cotutelle) soutenues dans la thematique´ combinatoire entre 2003 et 2007. Actuellement cinq theses` sont en preparation´ encadrees´ par D. Rossin (1), S. Corteel (2) et V. Ravelomanana (2). A la rentree´ 2012, nous prevoyons´ l’arrivee´ de deux nouveaux etudiants´ encadres´ respectivement par G. Chapuy et J. Lo- vejoy : W. Fang (ENS) et J. Dousse (ENS Lyon). Cette evolution´ du groupe a evidemment´ inﬂuence´ une evolution´ scientiﬁque. Le groupe se concentre dorenavant´ sur des aspects liant combinatoire bijective, analytique, algebrique´ et enum´ erative´ mais aussi avec de fortes interactions avec la physique, les probabilites´ et la theorie´ des nombres.

4.1.3 Objectifs de l’equipe´

Les objectifs de l’equipe´ sont de nous placer comme un des intervenants incontournables dans la recherche franc¸aise et internationale, mais aussi de fonctionner comme un groupe ou` chaque membre a sa place. Nous venons de pays et de domaines differents´ et travaillons reguli´ erement` avec des

211 CHAPITRE 4. PROJET SCIENTIFIQUE : COMBINATOIRE mathematiciens´ et des physiciens. Notre but en tant qu’equipe´ est de garder notre bonne humeur en offrant une place a` tous (locaux et visiteurs). Pour cela nous organisons le groupe de lecture du mardi avec une thematique´ differente´ chaque annee.´ En 2012, nous avons ainsi etudier´ les equations´ KP provenant de la physique thorique´ et leur lien avec l’enum´ eration´ de carte. Ce groupe a ainsi reuni´ les doctorants et permanents de lequipe´ mais aussi des doctorants et permanents de du CEA, de l’IGM et du LIX. Nous gardons avant tout en teteˆ notre objectif principal : des resultats´ de recherche judicieux. Ainsi nous presentons´ en 2012 de nombreux resultats´ a` SODA et FPSAC.

4.1.4 Programme prevu´ dans le contexte local, national et international

Notre particularite´ actuelle est d’etreˆ un groupe qui a des forces dans differents´ domaines de la combinatoire : bijective, analytique, algebrique´ et enum´ erative´ tout en collaborant avec des physiciens et des mathematiciens.´ Nos objectifs a` moyen terme sont de continuer nos travaux de recherche dans nos domaines d’excellence et de nous positionner comme des experts mondiaux de ces domaines. Nous detaillons´ ci-dessous trois de nos domaines d’excellence.

4.1.4.1 Combinatoire des cartes

Le but de ce theme` est de continuer le developpement´ de la combinatoire bijective des cartes et de concevoir une approche gen´ erale´ pour expliquer des formules d’enum´ eration´ mysterieuse´ apparues recemment.´ En plus de l’ingredient´ bijectif, le but est aussi d’y ajouter de la combinatoire algebrique´ et de la physique theorique´ pour obtenir de nouveaux resultats´ et en particulier les propriet´ es´ statistiques. Enﬁn un objectif est d’utiliser les objects combinatoires pour resoudre´ des problemes` venant de la combinatoire algebrique.´ Une these` commencera sur ce theme` en 2012 et l’ANR JCJC Cartaplus commencera en 2013.

4.1.4.2S eries´ hypergeom´ etriques´ et fonctions symetriques´

Dans ce theme,` nous souhaitons continuer nos recherches sur les series´ hypergeom´ etriques´ et leur lien avec la combinatoire et la theorie´ des nombres ; et en particulier les fonctions Mock-Theta. Nous souhaitons aussi nous diversiﬁer avec des gen´ eralisations´ de ces questions par des methodes´ et des problemes` de physiques, de polynomesˆ orthogonaux (multivaries)´ et des fonctions symetriques.´ Ceci donne lieu a` beaucoup de tres` jolis problemes` enum´ eratifs.´ Deux theses` sont en cours sur ces themes` et une these` commencera en 2012. Ce theme` est ﬁnance´ par l’ANR IComb.

4.1.4.3 Analyse d’algorithmes et combinatoire analytique

Le but de ce theme` est de poursuivre les recherches dans la lignee´ lancee´ par Philippe Flajolet : l’analyse d’algorithmes en utilisant la combinatoire analytique. Nous souhaitons aussi aller plus loin et attaquer des problemes` lies´ fortement a` l’informatique actuelle. En particulier, nous souhaiterions developper´ les etudes´ des reseaux´ aleatoires´ et la candidature de J. Salez au CNRS cette annee´ allait dans ce sens. Nous souhaitons aussi developper´ nos interactions avec les probabilistes. Deux theses` sont en cours sur ces themes.` Ce theme` est ﬁnance´ par l’ANR Magnum.

Tous ces themes` sont des themes` pointus et extremement` actifs mondialement. Nous sommes en bonne place pour relever ces deﬁs´ avec nos collaborateurs. D’autres themes` seront developp´ es´ dans l’equipe´ comme les algorithmes de gen´ eration,´ la combinatoire des permutations, les jolies bijections. . .

4.1.5 Prospective, positionnement dans la communaute´ scientiﬁque, et evolution´ a` moyen terme

La combinatoire est par essence une discipline d’interfaces. Ses techniques et ses problematiques´ sont constamment renouvelees´ par de tres` nombreuses interactions avec d’autres domaines de l’informatique

212 CHAPITRE 4. PROJET SCIENTIFIQUE : COMBINATOIRE theorique,´ mais aussi avec les autres sciences dures. Pour se maintenir au plus haut niveau dans ce renouvellement constant, trois el´ ements´ cles´ sont l’attractivite´ vis a` vis de l’exterieur,´ l’effervescence au sein du groupe, et l’encadrement de doctorants. Ces trois el´ ements´ complementaires´ reposent sur un etat´ d’esprit tourne´ vers la remise en question permanente via de nombreux groupes de travail et seminaires,´ via la participation a` l’organisation de conferences,´ et via la complementarit´ e´ toujours nourrie des themes` de recherche et des competences´ mutuelles des membres de l’equipe.´ Notre projet est de nous positionner comme une equipe-cl´ e´ de la combinatoire en France et dans la region´ parisienne. Nous pouvons y parvenir du fait des competences´ de notre groupe, mais aussi de notre situation geographique.´ Ainsi, plusieurs chercheurs franciliens (Polytechnique, Marne la Vallee)´ assistent a` notre groupe de lecture et a` notre seminaire.´ Ce seminaire´ est par ailleurs une etape´ naturelle dans la visite en France de nombreux chercheurs etrangers.´ Cette attractivite´ n’est pas un objectif isole,´ elle est la condition de l’epanouissement´ de notre recherche, elle en est le ferment. Developper´ ce cycle vertueux (attractivite´ → meilleure recherche → attractivite),´ dej´ a` initie´ ces dernieres` annees,´ comme le montre la frequentation´ croissante de nos seminaires´ et la qualite´ de nos membres associes,´ est un important objectif a` moyen terme. Sur le plan scientifique, nos succes` futurs s’appuieront sur la complementarit´ e´ des competences´ mutuelles des membres de l’equipe´ : notre specificit´ e´ est d’etreˆ pluridisciplinaires au sein memeˆ de la combinatoire. Si nous restions individuellement isoles,´ cette variet´ e´ pourrait etreˆ une faiblesse, mais du fait de l’effervescence qui regne` dans nos groupes de travail qu’il est notre projet d’entretenir, elle fait notre force. Nous voulons devenir une equipe´ moteur qui allie les techniques de combinatoire enum´ erative´ (historiquement LABRI - Xavier Viennot), de combinatoire algebrique´ (historiquement LITP - Alain Lascoux et Marcel-Paul Schutzenberger)¨ et de combinatoire analytique (historiquement INRIA Roc- quencourt - Philippe Flajolet). Nous pourrons ainsi saisir les opportunites´ de recherche qui s’ouvriront dans ces domaines et a` leurs interfaces, mais aussi les initier (comme nous l’avons fait ces dernieres` annees´ dans les domaines des polynomesˆ orthogonaux, ou des graphes aleatoires´ ou des cartes). Pour atteindre ces objectifs, nous comptons sur nos permanents, nos membres associes´ mais aussi sur nos partenaires franciliens, nationaux et internationaux. L’essentiel sera pour nous de maintenir une ambiance scientifique bouillonnante. Dans cet esprit, nous souhaitons nous impliquer fortement dans la formation des jeunes chercheurs et leur accompagnement vers une carriere` prometteuse. Cela repose sur l’enseignement de la combinatoire (des` la licence puis dans les cours specialis´ es´ du M2 MPRI), sur l’encadrement de doctorants et leur association a` toutes nos activites,´ et plus largement sur le recrutement eventuels´ de postdocs ou permanents en fonction des opportunites´ que nous saurons saisir, ou creer.´ Plus gen´ eralement,´ en plus de nos activites´ de recherche, nous participons au rayonnement et a` l’organisation du domaine par d’autres activites´ scientifiques. Nous sommes a` l’origine du seminaire´ de Combinatoire Philippe Flajolet a` l’Institut Henri Poincare´ qui a lieu tous les deux mois et regroupe la communaute´ combinatoire francilienne et accueille de prestigieux orateurs internationaux. Nous allons aussi organiser la conference´ internationale FPSAC en 2013 qui est la conference´ la plus importante du domaine (environ 180 a` 200 participants par an). Nous participons aussi a` une proposition de trimestre combinatoire a` l’IHP en collaboration avec des chercheurs de Paris 6, de Paris-Sud et de Marne la Vallee.´

4.1.6 Prospective, positionnement dans la communaute´ scientiﬁque, d’evolution´ a` long terme

Comme le montre notre projet a` moyen terme, nous souhaitons devenir une plaque tournante de la combinatoire française et mondiale, visible et incontournable. A` long terme, nous imaginons une equipe´ combinatoire forte, inscrite dans une large structure dedi´ ee´ a` l’informatique theorique,´ avec une reelle´ existence geographique´ (un lieu de visite naturel pour les combinatoristes du monde entier), et porteuse d’une vision de la combinatoire. Nous esperons´ avoir une influence sur une, puis plusieurs gen´ erations´ de jeunes chercheurs, en leur insufflant notre conception de la combinatoire tournee´ vers la variet´ e´ des

213 CHAPITRE 4. PROJET SCIENTIFIQUE : COMBINATOIRE techniques, la prise de recul dans les problematiques,´ et l’innovation. En termes de placement et de communautes,´ nous souhaitons rester pour longtemps a` la pointe des communautes´ FPSAC et AofA, c’est a` dire de la combinatoire algebrique,´ bijective, et analytique, sans man- quer de saisir les opportunites´ qui se presenteront´ dans la constitution de nouveaux groupes de recherche nationaux et internationaux. Nous souhaitons ainsi contribuer au developpement´ de notre domaine en concertation et en collaboration avec les acteurs franciliens (LIX, LIP6, LIPN, IGM), nationaux (LA- BRI, ICJ) europeens´ et internationaux. Enfin, nous imaginons developper´ une politique de membres associes´ similaire a` celle initiee´ il y a longtemps par le LaCIM, a` Montreal,´ qui a su construire au fil des annees´ une longue liste de partenaires prestigieux au sein de plusieurs gen´ erations.´ Aujourd’hui, presque tout combinatoriste dans le monde a un lien, fut-ilˆ tenu,´ avec cette equipe´ de Montreal.´ Par exemple, quatre membres de lequipe´ font partie du LIRCO (LIA entre le CNRS et le LaCIM), et un membre de lequipe´ est membre associe´ du LaCIM. Notre projet a` long terme est de nous retrouver dans vingt ou trente ans dans une situation comparable a` celle du LaCIM aujourd’hui, tout en conservant le dynamisme et la specificit´ e´ de notre vision de la combinatoire.

4.2 Mise en œuvre du projet

4.2.1 Politique scientiﬁque

Notre politique scientiﬁque est en cours d’elaboration.´ Pour le moment, nous fonctionnons en mode collegial´ et prenons des decisions´ pour les etudiants´ postdocs, invites´ et candidats CNRS ensemble. Pour les collaborations et discussions scientiﬁques, tout se fait naturellement car nous echangeons´ et communiquons quotidiennement.

4.2.2 Partenariats dans la recherche et l’enseignement superieur´

Nos partenariats dans la recherche englobent tous les laboratoires français ou` la combinatoire est represent´ ee´ : IGM, LIP6, LIX, LaBRI, LIPN, ICJ. Nous continuerons ces interactions ainsi que la participation aux groupes de travail du GDR-IM ALEA et combinatoire algebrique.´ Nous veillerons a` continuer nos collaborations internationales et mettre en place des partenariats officiels avec nos pays de predilections.´ En particulier, plusieurs membres de l’equipe´ ont un lien etroit´ avec Madagascar et des partenariats officiels d’enseignement se mettent en place. De plus, nous continuerons nos liens privilegi´ es´ avec les Etats-Unis, le Canada, l’Allemagne, l’Italie. . .

4.2.3 Vie de l’equipe´

Nous sommes tres` actifs dans le recrutement de doctorants graceˆ aux cours de combinatoire et d’analyse d’algorithmes du MPRI mais aussi par d’autres ﬁlieres.` Ainsi nous avons actuellement une doctorante australienne (Master U. of Melbourne) et un doctorant professeur en lycee´ (M2 proba). Nous continuerons notre prospective. Au niveau postdoctoral, nous proposons des candidats au concours de la FSMP (une dizaine de candidats serieux´ nous ont contacte´ en 2011) et avons recrute´ JS Kim graceˆ a` l’ANR IComb. Nous aurons de bons candidats dans les annees´ a` venir. Nous sommes aussi actifs pour accueillir des professeurs invites´ chaque annee´ et nous continuerons cette politique qui permet de mettre en oeuvre des collaborations a` long terme. Pour continuer a` fonctionner comme un bon groupe, nous souhaitons encourager et soutenir les enseignants-chercheurs dans leur recherche et encourager nos maˆıtres de conferences´ a` (co)-encadrer les etudiants´ et a` plus collaborer avec les chercheurs. Nous soutiendrons les demandes de del´ egation.´ Nous devons permettre aux maˆıtres de conference´ d’avoir une activite´ de recherche importante. Pour developper´ nos competences,´ nous comptons aussi sur le recrutement de nouveaux permanents. Ainsi depuis notre creation,´ nous avons eu plusieurs candidats brillants qui ont

214 CHAPITRE 4. PROJET SCIENTIFIQUE : COMBINATOIRE propose´ notre equipe´ comme equipe´ d’affectation potentielle pour un recrutement CNRS : Vincent Pi- laud (2011), Justin Salez (2012) et Andrea Sportiello (2011-2012 et qui avait aussi candidate´ dans notre equipe´ a` une chaire junior de la FSMP et a et´ e´ classe´ deuxieme).` Ils ont tous et´ e´ classes´ aux concours CNRS. Nous continuerons cette politique d’incitation de jeunes chercheurs brillants et nous esperons´ que l’Institut INS2I choisira a` l’avenir d’affecter un nouveau chercheur CNRS dans notre equipe.´ Nous esperons´ aussi a` moyen terme pouvoir accueillir un nouveau maˆıtre de conferences.´ En particulier, nous cherchons quelqu’un dans le domaine des structures aleatoires´ qui pourrait travailler et collaborer en particulier avec V. Ravelomanana mais aussi avec G. Chapuy.

4.2.4 Recherche de moyens

Pour la recherche de moyens, deux membre de l’equipe´ ont postule´ aux ERC starting grants et ont et´ e´ bien classes.´ Neanmoins´ a` part quelques petits projets bilateraux,´ l’ANR est notre ﬁnanceur principal. Nous continuerons a` soumettre a` l’ANR. Par exemple, G. Chapuy vient d’obtenir une ANR JCJC avec des chercheurs du CEA et du LIX. Il est le porteur de ce projet. En 2012, nous soumettrons d’autres demandes a` l’ANR. Nous avons d’autres projets. En particulier, nous comptons multiplier nos projets bilateraux´ europeens´ : Espagne, Allemagne, Irlande. . . et aussi en Amerique´ du Nord, en particulier avec le France-Berkeley fund. Nous serons aussi attentifs aux ﬁnancements europeens´ (ESF et ERC).

4.2.5 Diffusion des resultats´

Notre strategie´ de publication restera classique : soumission aux conferences´ importantes (AofA, SODA, FPSAC) et aux journaux internationaux.

215 CHAPITRE 4. PROJET SCIENTIFIQUE : COMBINATOIRE

INTERNE

–Soutien aux ma

–Peu deconf publications communes erence´

ˆıtres de

– Jeunesse Faiblesse – Interactions scientiﬁques – Miseprojets en place communs de

– Beaucoup de doctorantsForce NEGATIF S W

POSITIF O T –Forte attractivit Opportunit –Collaborations internationales –Collaborations nationales –Bons candidats postdoc Menace ´ et CNRS e´ equipe e´

– Peu de recrutements – Peu d’affectations dans l’

EXTERNE

FIGURE 4.1 – Analyse SWOT de l’equipe´ combinatoire

216 Chapitre 5

Liste des publications : Combinatoire

ACL : Articles dans des revues internationales ou nationales

[ABDH12a] J.-C. Aval, A. Boussicault, S. Dasse-Hartaut. “Dyck tableaux”. Theoretical Computer Science (2012). to appear. [ABL11a] S. Ahlgren, K. Bringmann, J. Lovejoy. “`-adic properties of smallest parts functions”. Adv. Math. 228.1 (2011), pp. 629–645. [ABL11b] C. Alfes, K. Bringmann, J. Lovejoy. “Automorphic properties of generating functions for generalized odd rank moments and odd Durfee symbols”. Math. Proc. Cambridge Philos. Soc. 151.3 (2011), pp. 385–406. [ACS09] G. E. Andrews, S. Corteel, C. D. Savage. “On q-series identities arising from lecture hall partitions”. Int. J. Number Theory 5.2 (2009), pp. 327–337. [BBG12] G. Borot, J. Bouttier, E. Guitter. “A recursive approach to the O(n) model on random maps via nested loops”. J. Phys. A: Math. Theor. 45.045002 (2012). [BBLNOPR11] F. Barsi, A. A. Bertossi, C. Lavault, A. Navarra, S. Olariu, M. Cristina Pinotti, V. Ravelomanana. “Efficient Location Training Protocols for Heterogeneous Sensor and Actor Networks”. IEEE Trans. Mob. Comput. 10.3 (2011), pp. 377–391. [BBPR10b] F. Bassino, M. Bouvel, A. Pierrot, D. Rossin. “Deciding the finiteness of the number of simple permutations contained in a wreath-closed class is polynomial”. Pure Mathematics and Applications 21.2 (2010). [BBR11] F. Bassino, M. Bouvel, D. Rossin. “Enumeration of Pin-Permutations”. Electronic Journal of Combinatorics 18.1 (2011). Paper P57. [BC11a] O. Bernardi, G. Chapuy. “A bijection for covered maps, or a shortcut between Harer- Zagiers and Jacksons formulas”. J. Comb. Theory, Ser. A 118.6 (2011), pp. 1718–1748. [BC11b] O. Bernardi, G. Chapuy. “Counting unicellular maps on non-orientable surfaces”. Adv. Appl. Math. 47.2 (2011), pp. 259–275. [BDPR07] A. Bernini, F. Disanto, R. Pinzani, S. Rinaldi. “Permutations defining convex permutominoes”. J. Integer Seq. 10.9 (2007), Article 07.9.7, 26. [BG12] J. Bouttier, E. Guitter. “Planar maps and continued fractions”. Comm. Math. Phys. 303.3 (2012), pp. 623–662. [BHL11] K. Bringmann, K. Hikami, J. Lovejoy. “On the modularity of the unified WRT invariants of certain Seifert manifolds”. Adv. in Appl. Math. 46.1-4 (2011), pp. 86–93. [BL08] K. Bringmann, J. Lovejoy. “Rank and congruences for overpartition pairs”. Int. J. Number Theory 4.2 (2008), pp. 303–322.

217 CHAPITRE 5. LISTE DES PUBLICATIONS : COMBINATOIRE

[BL09] K. Bringmann, J. Lovejoy. “Overpartitions and class numbers of binary quadratic forms”. Proc. Natl. Acad. Sci. USA 106.14 (2009), pp. 5513–5516. [BLO09] K. Bringmann, J. Lovejoy, R. Osburn. “Rank and crank moments for overpartitions”. J. Number Theory 129.7 (2009), pp. 1758–1772. [BLO10] K. Bringmann, J. Lovejoy, R. Osburn. “Automorphic properties of generating functions for generalized rank moments and Durfee symbols”. Int. Math. Res. Not. IMRN 2 (2010), pp. 238–260. [BP08b] M. Bouvel, E. Pergola. “Posets and Permutations in the Duplication-Loss Model”. Pure Mathematics and Applications 19.2-3 (2008), pp. 71–80. [BP10] M. Bouvel, E. Pergola. “Posets and Permutations in the Duplication-Loss Model: Minimal Permutations with d Descents”. Theoretical Computer Science 411.26-28 (2010). [BR09] M. Bouvel, D. Rossin. “A variant of the tandem duplication - random loss model of genome rearrangement”. Theoretical Computer Science 410 (2009), pp. 847–858. [CFGMN11] G. Chapuy, E.´ Fusy, O. Gimenez,´ B. Mohar, M. Noy. “Asymptotic enumeration and limit laws for graphs of ﬁxed genus”. J. Comb. Theory, Ser. A 118.3 (2011), pp. 748–777. [Cha11] G. Chapuy. “A new combinatorial identity for unicellular maps, via a direct bijective approach”. Adv. Appl. Math. 47.4 (2011), pp. 874–893. [CJVW11] S. Corteel, M. Josuat-Verges,` L. K. Williams. “The matrix ansatz, orthogonal polynomials, and permutations”. Adv. in Appl. Math. 46.1-4 (2011), pp. 209–225. [CK11a] G. Chapuy, I. Klimann. “On the supports of recognizable series over a ﬁeld and a single letter alphabet”. Inf. Process. Lett. 111.23-24 (2011), pp. 1096–1098. [CK11b] S. Choi, J.-S. Kim. “Combinatorial rigidity of 3-dimensional simplicial polytopes”. Inter- nation Mathematics Research Notices 8 (2011), pp. 1935–1951. [CK11c] S. Corteel, J.-S. Kim. “Combinatorics on permutation tableaux of type A and type B”. European J. Combin. 32.4 (2011), pp. 563–579. [CKL09] D. Choi, S.-Y. Kang, J. Lovejoy. “Partitions weighted by the parity of the crank”. J. Com- bin. Theory Ser. A 116.5 (2009), pp. 1034–1046. [CL09] S. Corteel, J. Lovejoy. “Overpartitions and the q-Bailey identity”. Proc. Edinb. Math. Soc. (2) 52.2 (2009), pp. 297–306. [CLM08] S. Corteel, J. Lovejoy, O. Mallet. “An extension to overpartitions of the Rogers- Ramanujan identities for even moduli”. J. Number Theory 128.6 (2008), pp. 1602–1621. [CN09] S. Corteel, P. Nadeau. “Bijections for permutation tableaux”. European J. Combin. 30.1 (2009), pp. 295–310. [CRVP10] J. Cardinal, V. Ravelomanana, M. Valencia-Pabon. “Minimum sum edge colorings of mul- ticycles”. Discrete Applied Mathematics 158.12 (2010), pp. 1216–1223. [CSV11] S. Corteel, C. Savelief, M. Vuletic.´ “Plane overpartitions and cylindric partitions”. J. Com- bin. Theory Ser. A 118.4 (2011), pp. 1239–1269. [CW10] S. Corteel, L. K. Williams. “Staircase tableaux, the asymmetric exclusion process, and Askey-Wilson polynomials”. Proc. Natl. Acad. Sci. USA 107.15 (2010), pp. 6726–6730. [CW11] S. Corteel, L. K. Williams. “Tableaux combinatorics for the asymmetric exclusion process and Askey-Wilson polynomials”. Duke Math. J. 159.3 (2011), pp. 385–415. [DDPR12] F. Disanto, E. Duchi, R. Pinzani, S. Rinaldi. “Polyominoes Determined by Permutations: Enumeration via Bijections”. Annals of Combinatorics 16.1 (2012), pp. 57–75.

218 CHAPITRE 5. LISTE DES PUBLICATIONS : COMBINATOIRE

[DFPR07] F. Disanto, A. Frosini, R. Pinzani, S. Rinaldi. “A closed formula for the number of convex permutominoes”. Electron. J. Combin. 14.1 (2007), Research Paper 57, 17. [DFPR08] F. Disanto, A. Frosini, M. Poneti, S. Rinaldi. “A poset structure for row convex permuto- minides”. Pure Math. Appl. (PU.M.A.) 19.2-3 (2008), pp. 81–91. [DFPR10] F. Disanto, L. Ferrari, R. Pinzani, S. Rinaldi. “Catalan pairs: A relational-theoretic approach to Catalan numbers”. Adv. in Appl. Math. 45.4 (2010), pp. 505–517. [DFR11] F. Disanto, A. Frosini, S. Rinaldi. “Square involutions”. J. Integer Seq. 14.3 (2011), Article 11.3.5, 15. [DFRP08] F. Disanto, A. Frosini, S. Rinaldi, R. Pinzani. “The combinatorics of convex permutominoes”. Southeast Asian Bull. Math. 32.5 (2008), pp. 883–912. [DHH12] S. Dasse-Hartaut, P. Hitczenko. “Greek letters in random staircase tableaux”. Random Structures and Algorithms (2012). to appear. [DR11] H. Daude,´ V. Ravelomanana. “Random 2 XORSAT Phase Transition”. Algorithmica 59.1 (2011), pp. 48–65. [DRS08] E. Duchi, S. Rinaldi, G. Schaeffer. “The number of Z-convex polyominoes”. Adv. in Appl. Math. 40.1 (2008), pp. 54–72. [DS08] E. Duchi, G. Schaeffer. “A combinatorial approach to jumping particles: the parallel TA- SEP”. Random Structures Algorithms 33.4 (2008), pp. 434–451. [FPP11] J. Ferte,´ V. Pilaud, M. Pocchiola. “On the number of simple arrangements of ﬁve double pseudolines”. Discrete Comput. Geom. 45.2 (2011), pp. 279–302. [FPS08] E. Fusy, D. Poulalhon, G. Schaeffer. “Dissections, orientations, and trees with applications to optimal mesh encoding and random sampling”. ACM Trans. Algorithms 4.2 (2008), Art.19, 48pp. [FPS09] E. Fusy, D. Poulalhon, G. Schaeffer. “Bijective counting of plane bipolar orientations and Schnyder woods”. European J. Combin. 30.7 (2009), pp. 1646–1658. [Kim11a] J.-S. Kim. “Chain enumeration of k-divisible noncrossing partitions of classical types”. J. Comb. Theory, Ser. A 118 (2011), pp. 879–898. [Kim11b] J.-S. Kim. “Front representation of set partitions”. SIAM Journal Discrete Mathematics 25 (2011), pp. 447–461. [Kim11c] J.-S. Kim. “New interpretations for noncrossing partitions of classical types”. J. Comb. Theory, Ser. A 118 (2011), pp. 1168–1189. [LM08a] J. Lovejoy, O. Mallet. “n-color overpartitions, twisted divisor functions, and Rogers- Ramanujan identities”. South East Asian J. Math. Math. Sci. 6.2 (2008), pp. 23–36. [LM08b] J. Lovejoy, O. Mallet. “Overpartition pairs and two classes of basic hypergeometric series”. Adv. Math. 217.1 (2008), pp. 386–418. [LO08] J. Lovejoy, R. Osburn. “Rank differences for overpartitions”. Q. J. Math. 59.2 (2008), pp. 257–273.

[LO09] J. Lovejoy, R. Osburn. “M2-rank differences for partitions without repeated odd parts”. J. Theor.´ Nombres Bordeaux 21.2 (2009), pp. 313–334.

[LO10] J. Lovejoy, R. Osburn. “M2-rank differences for overpartitions”. Acta Arith. 144.2 (2010), pp. 193–212. [LO11] J. Lovejoy, R. Osburn. “Quadratic forms and four partition functions modulo 3”. Integers 11 (2011), A4, 6.

219 CHAPITRE 5. LISTE DES PUBLICATIONS : COMBINATOIRE

[Lov08b] J. Lovejoy. “Rank and conjugation for a second Frobenius representation of an overpartition”. Ann. Comb. 12.1 (2008), pp. 101–113. [Lov10a] J. Lovejoy. “On identities involving the sixth order mock theta functions”. Proc. Amer. Math. Soc. 138.7 (2010), pp. 2547–2552. [Lov10b] J. Lovejoy. “Partitions with rounded occurrences and attached parts”. Ramanujan J. 23.1-3 (2010), pp. 307–313. [Lov12a] J. Lovejoy. “Ramanujan-type partial theta functions and conjugate Bailey pairs”. Ramanu- jan J. (2012). to appear. [MMR10] R. Mantaci, S. Mantaci, A. Restivo. “Balance Properties and Distribution of Squares in Circular Words.” Int. J. Found. Comput. Sci. 21.4 (2010), pp. 647–664. [MPP11] B. Matschke, J. Pfeiﬂe, V. Pilaud. “Prodsimplicial-neighborly polytopes”. Discrete Com- put. Geom. 46.1 (2011), pp. 100–131. [NPRSC10] A. Navarra, M. C. Pinotti, V. Ravelomanana, F. B. Sorbelli, R. Ciotti. “Cooperative training for high density sensor and actor networks”. IEEE Journal on Selected Areas in Com- munications 28.5 (2010), pp. 753–763. [PS09] V. Pilaud, F. Santos. “Multitriangulations as complexes of star polygons”. Discrete Com- put. Geom. 41.2 (2009), pp. 284–317. [Rav10a] V. Ravelomanana. “Birth and growth of multicyclic components in random hypergraphs”. Theor. Comput. Sci. 411.43 (2010), pp. 3801–3813.

Publication [CK11a] is joint with team ”Automata”. C-INV : Conferences´ invitees´

[Cor09] S. Corteel. “Enumeration of Fillings of Young Diagrams”. Canadam 09. Montreal,´ Ca- nada, 2009.

C-ACTI : Communications avec actes de conferences´ internationales

[AB12] M. Albenque, J. Bouttier. “Constellations and multicontinued frc-actions: application to Eulerian triangulations”. Proceedings of the 24th International Conference on Formal Po- wer Series and Algebraic Combinatorics. Nagoya, Japan, 2012. [BCMR09] M. Bouvel, C. Chauve, M. Mishna, D. Rossin. “Average-Case Analysis of Perfect Sorting by Reversals”. CPM’ 09: Proceedings of the 20th annual symposium on Combinatorial Pattern Matching. Vol. 5577. Lecture Notes in Computer Science. Springer, 2009, pp. 314– 325. [BDGR11] N.-R. Beaton, F. Disanto, A. Guttmann, S. Rinaldi. “On the enumeration of column-convex permutominoes”. 23rd International Conference on Formal Power Series and Algebraic Combinatorics (FPSAC 2011). Discrete Math. Theor. Comput. Sci. Proc., AO. Assoc. Dis- crete Math. Theor. Comput. Sci., Nancy, 2011, pp. 111–122. [BMCPR12] M. Bousquet-Melou,´ G. Chapuy, Louis-Franc¸ois Preville-Ratelle.´ “The representation of the symmetric group on m-Tamari intervals”. Proceedings of the 24th International Conference on Formal Power Series and Algebraic Combinatorics. Nagoya, Japan, 2012.

[BP11] J. Bokowski, V. Pilaud. “On the generation of topological (nk)-conﬁgurations”. 23rd Ca- nadian Conference on Computational Geometry (CCCG’11). 2011.

220 CHAPITRE 5. LISTE DES PUBLICATIONS : COMBINATOIRE

[BRV07] M. Bouvel, D. Rossin, S. Vialette. “Longest Common Separable Pattern Among Permuta- tions”. CPM ’07: Proceedings of the 18th annual symposium on Combinatorial Pattern Matching. Vol. 4580. Lecture Notes in Computer Science. London, Canada: Springer- Verlag, 2007, pp. 316–327. [CFF12] G. Chapuy, V. Feray,´ E.´ Fusy. “A simple model of trees for unicellular maps”. Proceedings of the 24th International Conference on Formal Power Series and Algebraic Combinato- rics. Nagoya, Japan, 2012. [CJVPR09] S. Corteel, M. Josuat-Verges,` T. Prellberg, M. Rubey. “Matrix ansatz, lattice paths and rook placements”. 21st International Conference on Formal Power Series and Algebraic Combinatorics (FPSAC 2009). Discrete Math. Theor. Comput. Sci. Proc., AK. Assoc. Dis- crete Math. Theor. Comput. Sci., Nancy, 2009, pp. 313–324. [CN08] S. Corteel, P. Nadeau. “Bijections for permutation tableaux”. 20th Annual International Conference on Formal Power Series and Algebraic Combinatorics (FPSAC 2008). Dis- crete Math. Theor. Comput. Sci. Proc., AJ. Assoc. Discrete Math. Theor. Comput. Sci., Nancy, 2008, pp. 13–24. [DDRS11] F. Disanto, E. Duchi, S. Rinaldi, G. Schaeffer. “Permutations with few internal points”. The Sixth European Conference on Combinatorics, Graph Theory and Applications, Euro- Comb 2011. Vol. 38. Electronic Notes in Discrete Mathematics. Elsevier, 2011, pp. 291– 296. [DFPR09] F. Disanto, L. Ferrari, R. Pinzani, S. Rinaldi. “Combinatorial properties of Catalan pairs”. European Conference on Combinatorics, Graph Theory and Applications (EuroComb 2009). Vol. 34. Electron. Notes Discrete Math. Elsevier Sci. B. V., Amsterdam, 2009, pp. 429–433. [DMRR12] H. Daude,´ C. Mart´ınez, V. Rasendrahasina, V. Ravelomanana. “The MAX-CUT of sparse random graphs”. SODA. 2012, pp. 265–271. [DP08] E. Duchi, D. Poulalhon. “On square permutations”. Fifth Colloquium on Mathematics and Computer Science. Discrete Math. Theor. Comput. Sci. Proc., AI. Assoc. Discrete Math. Theor. Comput. Sci., Nancy, 2008, pp. 207–222. [GBN07] D. Gouyou-Beauchamps, P. Nadeau. “Growth diagrams, Ribbon tableaux, Involution principle”. Proceedings of the 19th International Conference on Formal Power Series and Algebraic Combinatorics. Tianjin, 2007. [Lan12] R. Langer. “Enumeration of Cylindric Plane Partitions”. Proceedings of the 24th Interna- tional Conference on Formal Power Series and Algebraic Combinatorics. Nagoya, Japan, 2012. [Mal08] O. Mallet. “n-color overpartitions, lattice paths, and multiple basic hypergeometric series”. 20th Annual International Conference on Formal Power Series and Algebraic Combinato- rics (FPSAC 2008). Discrete Math. Theor. Comput. Sci. Proc., AJ. Assoc. Discrete Math. Theor. Comput. Sci., Nancy, 2008. [MM11] R. Mantaci, P. Massazza. “From Linear Partitions to Parallelogram Polyominoes.” Deve- lopments in Language Theory. Ed. by Giancarlo Mauri and Alberto Leporati. Vol. 6795. Lecture Notes in Computer Science. Springer, 2011, pp. 350–361. [MMR08] R. Mantaci, S. Mantaci, A. Restivo. “Balance Properties and Distribution of Squares in Circular Words.” Developments in Language Theory. Ed. by Masami Ito and Masafumi Toyama. Vol. 5257. Lecture Notes in Computer Science. Springer, 2008, pp. 504–515.

221 CHAPITRE 5. LISTE DES PUBLICATIONS : COMBINATOIRE

[PRW11] A. Pierrot, D. Rossin, J. West. “Adjacent transformations in permutations”. proceedings of FPSAC 2011 (23th International Conference on Formal Power Series and Algebraic Combinatorics), DMTCS proc. AO. 2011, pp. 765–776. [PS11] V. Pilaud, F. Santos. “The brick polytope of a sorting network”. 23th Annual International Conference on Formal Power Series and Algebraic Combinatorics (FPSAC 2011). 2011. [RR10] V. Rasendrahasina, V. Ravelomanana. “Limit Theorems for Random MAX-2-XORSAT”. LATIN. 2010, pp. 320–331.

C-COM : Communications orales sans actes en conferences´ internationales ou nationales

[ABDH12b] J.-C. Aval, A. Boussicault, S. Dasse-Hartaut. “The tree structure in staircase tableaux”. Conference Gen´ eration´ aleatoire´ de structures combinatoires (GASCom). 2012. [BBPR09] F. Bassino, M. Bouvel, A. Pierrot, D. Rossin. “Deciding the ﬁniteness of simple permutations contained in a wreath-closed class is polynomial.” Permutation Patterns. 2009. [BBPR10a] F. Bassino, M. Bouvel, A. Pierrot, D. Rossin. “A polynomial algorithm for deciding the ﬁniteness of the number of simple permutations in permutation classes.” Permutation Pat- terns. 2010. [BBR09] F. Bassino, M. Bouvel, D. Rossin. “Permutations en epingles´ et structure dans les classes de permutations”. Journees´ annuelles du GT-Alea´ du GdR-IM. 2009. [BMMR09] M. Bousquet-Melou, R. Mantaci, F. Rakotondrajao. “Polynomial classes of permutations avoiding exactly two patterns.” Permutation Patterns. 2009. [Bou12a] J. Bouttier. “The nested loop approach to the O(n) model on random maps”. Workshop on Statistical Mechanics and Conformal Invariance, MSRI Berkeley, 2012. [Bou12b] J. Bouttier. “The nested loop approach to the O(n) model on random maps”. Conference on Conformal Invariance, Discrete Holomorphicity and Integrability. Helsinki, Finland, 2012. [BP08a] M. Bouvel, E. Pergola. “Posets and Permutations in the duplication-loss model”. Confe- rence Gen´ eration´ aleatoire´ de structures combinatoires (GASCom). 2008. [BR07] M. Bouvel, D. Rossin. “A variant of the tandem duplication - random loss model of genome rearrangement”. Permutation Patterns. 2007. [Cha10] G. Chapuy. “Combinatorics and Analysis in Spatial Probability”. Eurandom. Eindhoven, Netherlands, 2010. [Cha12] G. Chapuy. “Perspective in Discrete Mathematics”. Centre de Recerca Matematica` . Bar- celona, Spain, 2012. [CJVK12] S. Corteel, M. Josuat-Verges, J.S. Kim. “Combinatorics of permutation tableaux of type B”. GAScom 2012. 2012. [Cor10] S. Corteel. “Tableaux escaliers et polynomes d’Askey Wilson”. Journees´ de Combinatoire de Bordeaux 2010. 2010. [CPR11] G. Chapuy, A. Pierrot, D. Rossin. “On growth rates of wreath-closed permutation classes”. Permutation Patterns. 2011. [Duc12] E. Duchi. “Preuve bijective de la formule d’Hurwitz a` l’aide de mobiles.” Expose´ invite´ aux journes´ X.G. Viennot. 2012. [Lov08a] J. Lovejoy. “Andrews’ generalization of Selberg’s q-difference equations”. Combinatory Analysis 2008: Partitions, q-series, and Applications. 2008.

222 CHAPITRE 5. LISTE DES PUBLICATIONS : COMBINATOIRE

[Lov09] J. Lovejoy. “Q-series and class numbers, Mock theta functions and applications in combinatorics”. Algebraic geometry and mathematical physics. Max Planck Institute, Bonn, Germany, 2009. [Lov11] J. Lovejoy. “Congruences for smallest parts functions, Modular Forms and Mock Modular Forms and their Applications in Arithmetic”. Geometry and Physics. Trieste, Italy, 2011. [Lov12b] J. Lovejoy. “Ramanujan’s identities for the sixth order mock theta functions”. Symposium on Modular Forms, Mock Theta Functions, and Applications. Cologne, Germany, 2012. [MMP11a] J. Mairesse, A. Micheli, D. Poulalhon. “Comment minimiser une tresse”. Journees´ de Combinatoire de Bordeaux. 2011. [MMP11b] J. Mairesse, A. Micheli, D. Poulalhon. “Minimizing braids on four strands”. Braids. 2011. [OKNPPP11] A. Guiedes Oliviera, E. Kim, M. Noy, A. Padrol, J. Pfeiﬂe, V. Pilaud. “Polytopal complexes realizing products of graphs”. XIV Encuentros de Geometria Computacional. 2011. [PR11] A. Pierrot, D. Rossin. “On two-stack sorting”. Permutation Patterns. 2011. [PS10] V. Pilaud, F. Santos. “The brick polytope of a sorting network”. Culminating Workshop of the Semester on Discrete and Computation Geometry in Lausanne. 2010. [Rav10b] V. Ravelomanana. “Random 2-XOR-SAT and MAX-2-XOR-SAT and their phase transitions”. Expose´ long au groupe de travail Alea´ . 2010.

223 CHAPITRE 5. LISTE DES PUBLICATIONS : COMBINATOIRE

224 Chapitre 6

Annexes : Combinatoire

6.1 Composition et vie scientiﬁque

Responsable : Sylvie Corteel (DR CNRS)

6.1.1 Liste actuelle des membres

6.1.1.1 Membres permanents (2012)

Guillaume Chapuy (CR) Sylvie Corteel (DR) Enrica Duchi (MdC) Jeremy Lovejoy (CR) Roberto Mantaci (MdC - HDR) Anne Micheli (MdC) Dominique Poulalhon (MdC - en detachement´ 2009-2013) Vlady Ravelomanana (Pr)

6.1.1.2 Doctorants et post-doctorants (2012)

2011- : Antoine Crouzet (direction Vlady Ravelomanana) Prof lycee´ 2010- : Sandrine Dasse-Hartaut (direction Sylvie Corteel) AM 2010- : Elie de Panaﬁeu (direction Vlady Ravelomanana) AMN 2011- : Robin Langer (direction Sylvie Corteel) CNRS 2009- : Adeline Pierrot (direction Dominique Rossin) AMN

6.1.1.3 Visiteurs de longue duree´ (2012)

Pour l’annee´ 2011-2012, en detachement´ du CEA. Jer´ emie´ Bouttier (CEA)

6.1.1.4 Autres (2012)

Membres associes´ Philippe Biane (DR CNRS) Jer´ emie´ Bouttier (CEA)

225 CHAPITRE 6. ANNEXES : COMBINATOIRE

6.1.2 Anciens membres

6.1.2.1 Membres permanents (2007-2011)

Dominique Rossin (CR - HDR) mutation au LIX en 2009.

6.1.2.2 Doctorants et post-doctorants (2007-2011)

Doctorants 2006-2009 : Mathilde Bouvel (direction Dominique Rossin) CR CNRS au LABRI 2005-2008 : Olivier Mallet (direction Jeremy Lovejoy) Maˆıtre de Conferences´ a` Rouen 2009-2010 : Matthieu Josuat-Verges` (direction Sylvie Corteel, these` soutenue a` Paris-Sud) CR CNRS a` l’IGM. 2007-2010 : Filippo Di Santo (cotutelle direction Enrica Duchi) Post-doctorants 2008-2010 : Jang Soo Kim, Postdoc (ANR IComb) maintenant Assistant Professor University of Min- nesota (USA) 2008-2009 : Olivier Mallet, Ater (Paris-Diderot) maintenant Maˆıtre de Conferences´ a` Rouen 2007-2008 : Philippe Nadeau, Ater (Paris Diderot) maintenant CR CNRS a` l’ICJ 2010-2011 : Vincent Pilaud, Ater (Paris-Diderot) maintenant CR CNRS au LIX 2008-2009 : Yann Ponty, Postdoc (ANR Gamma) maintenant CR CNRS au LIX

6.1.2.3 Visiteurs de longue duree´ (2007-2011)

2010-2011 : Olivier Bodini (Paris 6) en del´ egation´ CNRS

6.1.3 Visiteurs

Olivier Bernardi (Prof invite,´ 2 semaines) Robert Osburn (University College Dublin - Prof invite,´ 1 mois) Juan Jose´ Rue´ (ICMAT, Madrid, ANR Magnum 4 mois) Marc Noy (UPC Barcelona, ANR Magnum 3 semaines) Lauren Williams (Berkeley, ANR Gamma, 1 mois)

6.1.4 Vie de l’equipe´

La vie scientiﬁque de l’equipe´ s’organise autour du groupe de lecture du mardi (organise´ par Guillaume Chapuy) et du seminaire´ du Jeudi (organise´ par Sylvie Corteel et Vlady Ravelomanana). Le groupe de lecture est un groupe hebdomadaire qui dure environ deux heures et qui est un presentation´ de chapitre de livre ou d’article prepar´ e´ par un des membres du groupe. Le theme` de 2010-2011 etait´ la combinatoire des (q, t)-Catalan base´ sur un livre de Jim Haglund (University of Pennsylvania) et celui de 2011-2012 est l’enum´ eration´ de cartes et les equations´ KP et est base´ sur les travaux d’Okounkov et de Goulden et Jackson. La plupart des membres de lequipe´ et principalement les doctorants participent au groupe de lecture mais il accueille aussi des autres chercheurs de la region´ parisienne : Polytehcnique, Orsay et Marne la Vallee.´ Le seminaire´ lui est plus classique. Il dure une heure et est un expose´ de travaux recents´ de l’orateur. Les orateurs sont locaux, nationaux ou internationaux. Depuis sa creation´ en Mars 2010, il a lieu environ 28 fois par an. Nous invitons particulierement` des jeunes chercheurs. L’equipe´ participe aussi a

226 CHAPITRE 6. ANNEXES : COMBINATOIRE l’organisation du seminaire´ de combinatoire Philippe Flajolet a` l’Institut Henri Poincare.´ Ce seminaire´ est bimestriel et s’organise autour de trois exposes´ faits par des chercheurs conﬁrmes.´ Il a et´ e´ cre´e´ a` l’Automne 2010 par Sylvie Corteel (LIAFA) et Michele` Soria (LIP6). Son but est de regrouper la communaute´ francilienne de combinatoire tous les deux mois.

6.1.4.1 Implication dans l’animation scientiﬁque et les responsabilites´ administratives locales, nationales et internationales

UFR : -2008 : Membre du conseil de l’UFR, de la commission des enseignements, responsable des moniteurs, representante´ de l’UFR aupres` du Departement´ Sciences Exactes, Dominique Poulalhon. 2007-2009 : Responsable du master Isifar, mention Informatique-Finance, Anne Micheli. 2010-2011 : Commission de suivi des etudiants´ des trois annees´ de licence, Anne Micheli. 2012- : Co-responsable des classes preparatoires´ aux Ecoles d’Ingenieurs´ de l’Universite´ Paris Diderot, Vlady Ravelomanana. 2012- : Membre du conseil de l’UFR et du bureau de l’UFR, Anne Micheli. Conseil scientifique de l’UFR, Sylvie Corteel (2010-2011) Guillaume Chapuy (2011- ) et Vlady Rave- lomanana (2010-). Laboratoire : Chargee´ de communication du LIAFA, Sylvie Corteel. Conseil du laboratoire, Enrica Duchi et Vlady Ravelomanana. Animation scientifique : 2010- : Seminaire´ hebdomadaire, Sylvie Corteel et Vlady Ravelomanana. 2011- : Groupe de lecture hebdomadaire, Guillaume Chapuy. 2010- : Seminaire´ Philippe Flajolet, Sylvie Corteel. 6.2 Contrats et projets scientifiques

6.2.1 Responsabilite´ de projets nationaux

Projet ICOMB. Type de projet : ANR JCJC. Titre detaill´ e´ : Interaction of Combinatorics Partenaires : LIAFA (CNRS et Univ. Diderot). Montant : 340Ke, Sylvie Corteel et Jeremy Lovejoy.

6.2.2 Participation a` des projets internationaux

Creation´ de l’Ecole Doctorale en Mathematiques´ et Informatique a` l’Universite´ d’Antananarivo, Vlady Ravelomanana. Projet franco-tunisien 09/R 15-7 DGRSRT-CNRS, Vlady Ravelomanana. ”Ramanujan-type congruences for overpartitions and overpartition pairs”, Ulysses - PHC Franco- Irlandais, Jeremy Lovejoy. Arithmetic Properties of Coeffcients of Modular Forms, Science Foundation Ireland Research Frontiers Programme, Jeremy Lovejoy.

6.2.3 Participation a` des projets nationaux

2007-2010 : ANR blanc Gamma : titre : Gen´ eration´ Aleatoire´ : Modeles,` Methodes,´ Algorithmes, partenaires : LIAFA, LIP6, IGM, LIPN, LRI, responsables : Dominique Rossin (LIAFA), Michele` Soria (LIP6), Fred´ erique´ Bassino (LIPN), Sylvie Corteel, Jeremy Lovejoy, Anne Micheli, Domi- nique Poulalhon, Vlady Ravelomanana.

227 CHAPITRE 6. ANNEXES : COMBINATOIRE

2009-2012 : ANR blanc BOOLE (ANR C9 BLAN 0011 01) responsable : Daniele` Gardy (PRISM – UVSQ), Vlady Ravelomanana. 2010-2013 : ANR blanc Magnum : titre : Methodes´ Algorithmiques pour la Gen´ eration´ aleatoire´ Non Uniforme : Modeles` et applications, partenaires : LIP6, INRIA, LIAFA, LIX, LIPN, IGM, responsables : Dominique Rossin (LIAFA), Michele` Soria (LIP6), Fred´ erique´ Bassino (LIPN). Roberto Mantaci, Anne Micheli, Adeline Pierrot, Vlady Ravelomanana.

6.3 Administration de la recherche

6.3.1 Activites´ editoriales´

Comite´ editorial´ de Annals of Combinatorics, Sylvie Corteel.

6.3.2 Gestion scientiﬁque de conferences´

Conference on “Prospects in q-series and modular forms,” July 14-16, 2010, University College Dublin, Ireland, Jeremy Lovejoy. Conference´ Hypergeometric series and their generalizations in algebra, geometry, number theory and physics, 29 Mai - 1er Juin 2012, Institut Henri Poincare,´ Jeremy Lovejoy. Seminaire´ Philippe Flajolet, Institut Henri Poincare,´ Sylvie Corteel. Formal Power Series and Algebraic Combinatorics, Universite´ Paris Diderot, 24-28 Juin 2013, toute l’equipe.´

6.3.2.1 Participation a` des comites´ de programmes

Formal Power Series and Algebraic Combinatorics 2008, 2010, 2012, Sylvie Corteel et Jeremy Love- joy. Canadam 2013, Sylvie Corteel. ACM-SIAM ANALCO 2012 (Analytic Algorithmics and Combinatorics), Vlady Ravelomanana.

6.3.3 Organisation d’ev´ enements´ scientiﬁques

6.3.3.1 Presidence´ de comites´ d’organisation

Formal Power Series and Algebraic Combinatorics, Uiversite´ Paris Diderot, 24-28 Juin 2013.

6.3.3.2 Participation a` des comites´ d’organisation

Journees´ ALEA 2009, Mars 2009, Anne Micheli et Dominique Poulalhon TGGT 2008 (Topological and Geometric Graph Theory), Paris, 19 au 23 mai 2008, Dominique Pou- lalhon

6.3.4 Participant a` des comites´ et jurys scientiﬁques

6.3.4.1 Au niveau international

Combinatorics Panel, National Science Foundation, Washington DC 2011, Sylvie Corteel.

6.3.4.2 Au niveau national

Comite´ de pilotage du groupe GDR-IM ALEA, Sylvie Corteel et Vlady Ravelomanana.

228 CHAPITRE 6. ANNEXES : COMBINATOIRE

6.3.4.3 Commissions de specialistes´

IUT de Marne-la-Vallee´ (2009,2010) et l’Universite´ de Marne-la-Vallee´ (2008), Anne Micheli. Universite´ Paris Nord (2010) et Universite´ Bordeaux I (2010), Sylvie Corteel. Paris Diderot (2007, 2008) et Paris Nord (2011), Dominique Poulalhon. Universite´ Descartes (2010, 2011, 2012), IUT Paris 5 (2011), Universite´ Paris-Nord (2010), Vlady Ravelomanana

6.3.4.4 Rapport de these`

2009 Francesca de Carli (Universite´ de Savoie, Enrica Duchi et Dominique Rossin) 2011 Hayat Cheballah (Paris Nord, Sylvie Corteel) 2011 Samuele Giraudo (Marne la Vallee,´ Sylvie Corteel) 2012 Adel Hamdi (Lyon, Sylvie Corteel)

Jury de these` : Marc Sage (2012, Sylvie Corteel et Vlady Ravelomanana). Jury d’habilitation : Fred´ eric´ Jouhet (2010, Jeremy Lovejoy). 6.4 Activites´ de formation, encadrement et evaluation´

6.4.1 Liste des theses` et HdR soutenues

6.4.1.1 Habilitations a` diriger les recherches

2010 : Sylvie Corteel, Diagrammes de Ferrers decor´ es.´

6.4.1.2 Theses` de doctorat

2008 : Olivier Mallet Autour des surpartitions et des identites´ de type Rogers-Ramanujan (sous la direction de Jeremy Lovejoy). Olivier est maˆıtre de conferences´ a` l’Universite´ de Rouen. 2009 : Mathilde Bouvel, Quelques problemes` combinatoires et algorithmiques sur les classes de permutations (sous la direction de Renzo Pinzani et Dominique Rossin). Mathilde est CR CRNS au LABRI. 2010 : Filippo Disanto, Some combinatorial problems on permutations, polyominoes and partially ordered sets (sous la direction de Enrica Duchi et Simone Rinaldi)

(Co-)encadrements de these` : Hichem Kenniche (Paris Nord, Vlady Ravelomanana, soutenance 2011), Vonjy Rasendrahasina (Paris Nord, Vlady Ravelomanana, soutenance prevue´ en 2012).

6.4.2 Enseignement dispense´

6.4.2.1 Cours universitaires en M2R

Cours C2-10 Algorithmique de la Combinatoire, MPRI, Dominique Poulalhon (2007), Sylvie Corteel (2009-2011), Guillaume Chapuy (2011-2012), Jeremy Lovejoy (2012). Cours C2-15 Analyse d’algorithmes, MPRI, Vlady Ravelomanana (2011-).

6.4.2.2 Ecoles thematiques´ et cours specialis´ es´

2011 : Conferencier´ invite´ a` l’ecole´ de Combinatoire et Algorithmique de Madagascar (ECAM). Res- ponsable du cours d’algorithmique, Roberto Mantaci.

229 CHAPITRE 6. ANNEXES : COMBINATOIRE

2011 : Cours d’Analyse de performance et simulations en Master Recherche Econometrie´ a` l’Universite´ d’Antananarivo, Vlady Ravelomanana. 2011 : Cours de Combinatoire Analytique au Departement´ des Mathematiques´ de Monastir, Vlady Ravelomanana. 2011 : Quasimodular forms and applications, Besse et Saint-Anastaise, Jeremy Lovejoy.

230 Part VI

Modeling and Veriﬁcation team

231

Chapter 1

Research report: Modeling and Veriﬁcation

1.1 General context and objectives Motivation and challenges: Computing systems are ubiquitous. Their reliability is a crucial issue since their misbehaviors can have unacceptable impact. The complexity of modern software/hardware systems implies the necessity of adopting formal and automated verification methods allowing either to detect subtile bugs that may occur in these systems, or to establish their correctness w.r.t. precisely defined criteria and specifications. It also important to develop such methods taking into account qualitative aspects (e.g., input-output relations, order constraints between events, termination of computation phases, etc.) as well as quantitative aspects (time separating occurrences of events, cost of computations in terms of resource consumption, etc.). Model checking is a well established formal approach for automatic verification. It has been successfully applied to various classes of systems, including hardware systems and some classes of software systems such as communication protocols, device drivers, and real-time controllers. However, its extension to wider classes of software systems, taking into account complex data and control aspects, remains a major challenge, both from the theoretical and practical viewpoints. Another important issue for the design of reliable systems is synthesis, that is, constructing a component (of a system) that is able to behave in conformance with some specification (of the whole system), what- ever its environment (i.e., the rest of the system) may do at each point in time. This problem is reducible to game solving (i.e., finding a winning strategy against the environment). Closely related problems are the verification of open systems (i.e., systems that must interact permanently with an uncontrollable environment), and compositional model checking.

Approach and objectives: The MV team aims at developing advanced algorithmic verification methods. Her work includes investigating theoretical and foundational issues as well as developing innovative techniques and efficient tools for automatic verification: We define automata-based formal models and logics for specifying the computations or the configurations of these systems, and we study the fundamental properties of these modeling and specification formalisms. We investigate in particular the decidability and the complexity of their verification problems, and the issue of designing efficient model-checking algorithms for them. In addition, we develop powerful analysis procedures that are able to handle wide classes of systems, either for bug detection (using under-approximations) or for establishing correctness (using abstraction techniques).

1.2 Main results in the period 2007-2012 Automata-Based Techniques: Regular Model Checking (RMC) is a generic, automata-based, symbolic verification approach for infinite-state systems. Finite-state word/tree automata are used to represent (potentially infinite) sets of configurations and transformations. RMC is applicable to various classes of systems such as networks of concurrent processes, programs with dynamic data structures, programs with integer variables, etc. Our contributions to RMC in 2007-12 concern mainly:

233 CHAPTER 1. RESEARCH REPORT: MODELING AND VERIFICATION

• Algorithms for nondeterministic automata: These automata provide more compact representations of regular languages/relations than canonical automata. We have developed an efficient algorithm for inclusion checking between tree automata, extending the approach of antichains originally defined for word automata 1. Moreover, we have developed efficient algorithms for tree automata reduction. Our approach is based on defining good approximations of language equivalence that can be checked in polynomial time [ABHKV08a; ABHKV08b; ABHKV09] 2. • Complexity of decision problems on automatic structures, i.e., structures for which basic relations are representable by finite-state automata, which allows to get an automata-based decision procedure for their first-order logic. An example is Presburger arithmetic (PA). While the complexity of deciding PA using quantifier elimination is known (there is a double-exponential non-deterministic time lower bound and a triple exponential deterministic time upper bound), the complexity of the automata-based decision procedure was unknown. We show in [DGH10] that it is triple- exponential as well. In [DGH12], we establish a general complexity result for the model checking of first-order formulas on automatic structures, by a thorough analysis (using Ehrenfeucht-Fra¨ısse´ games) of the construction of an automaton recognizing the models of a formula. Verification of Concurrent Systems: Verifying concurrent programs is hard even in the case of boolean programs. Boolean programs with two threads and recursive procedures are Turing powerful. Dynamic creation of threads, as well as the adopted memory model (which may not ensure sequential consistency), are other sources of complexity. Our main contributions on this topic in 2007-12 are: Decidability and complexity: We have identified classes of programs for which verification problems, mainly reachability queries, are decidable. We have investigated the effect of assumptions about (1) the network topology: acyclic networks of communicating pushdown systems [ABT08b], (2) the interaction between recursion and concurrency/task creation: asynchronous programs with task priorities and preemption [ABT08a], ordered use of stacks [ABH08; Ati10a; Ati10b], and (3) the transmission of information and accesses to shared memory between tasks: recursively parallel programs, a family of programs with isolated hierarchical parallel computations corresponding to concurrency constructs present in explicitly parallel programming languages such as CILK and X10 [BE12a]. Under approximate analysis for bug detection: Context bounding 3 is a popular bounding concept suitable for bug detection in multi-threaded programs. Importantly, it has been shown 4 that context-bounded analysis is compositionally reducible (by a code-to-code translation) to sequential program analysis. This allows to leverage existing analysis tools for sequential programs to the concurrent case. However, these works considered only programs with a fixed number of threads. In our work (in collaboration with S. Qadeer), we have extended context-bounding to programs with dynamic creation of threads, where the bound is defined per thread and not globally. We have established decidability and complexity results for this case [ABQ09; ABQ11], and also proposed a new concept, called delay bounding, which leads to a more scalable analysis[EQR11]. In [BEP11] we provide a unifying framework for bounded analysis of concurrent programs that is compositionally reducible to sequential analysis. Weak Memory Models: For performance reasons, modern multi-microprocessors implement weak memory consistency models that relax the program order between actions of a processor. Therefore, computations are not sequentially consistent (SC) in general, while most of the programmers are used to reason in SC. Then, given a memory model M, two problems must be addressed: (P1) checking whether a program running under M satisfies a specification, and (P2) checking whether a program is robust against M, that is, all its computations under M have counterparts under SC. We have established the first decidability and complexity results for these problems:

1. M. De Wulf et al.: Antichains: A New Algorithm for Checking Universality of Finite Automata. CAV’06, LNCS 4144. 2. Paper [ABHKV08a] received the best paper award at CIAA’08. 3. S. Qadeer, J. Rehof: Context-Bounded Model Checking of Concurrent Software. TACAS’05, LNCS 3440, 2005. 4. A. Lal, T. Reps: Reducing concurrent analysis under a context bound to sequential analysis. FMSD 35(1), 2009.

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• The state reachability problem is undecidable when writes are allowed to overtake speculatively reads, and it becomes decidable when this relaxation is forbidden, like in TSO for instance. (TSO is the model adopted, e.g., in SPARC and Intel x86 machine.) However, this problem is highly complex in general (non-primitive recursive) [ABBM10; ABBM12]. • The trace-robustness problem for TSO, i.e., checking if all computations possible under TSO are also possible under SC, is, surprisingly, only PSPACE-complete [BMM11]. We show that checking trace-robustness against TSO can be reduced to checking state reachability under SC. Verification of programs manipulating data structures: Reasoning about configurations of data structures requires the use of rich logics allowing to express various kind of constraints such as shape constraints (e.g., acyclicity, disjointness, etc.), size constraints (e.g., preservation of the length), set/multiset constraints (e.g., preservation of the elements), and data constraints (e.g., sortedness). Decidable logics: We have investigated logics offering a good trade-off between, on one hand, expressiveness and relevance for program specification, and on the other hand, decidability and closure properties that are useful for automatic verification. In [HIV08a; HIV08b], we introduce decidable logics for reasoning about arrays of integers, providing a decision procedure through a translation to flat counter automata. In [BDES09], we introduce a logic for reasoning about composite multi-linked structures, such as lists of lists or lists of doubly-linked lists for instance, carrying data over a domain with a decidable theory. The decision procedure is by a non-trivial small model argument. Invariant synthesis: In [BDERS10; BDES11], we develop a powerful approach, based on abstract- interpretation, for automatic synthesis of invariants of programs with dynamic singly-linked lists of integers. We introduce new abstract domains for reasoning about various kinds of constraints on the contents of lists, and we use them to define an efficient modular inter-procedural analysis that is ac- curate enough to generate, fully automatically, complex invariants for a wide class of programs. This class includes for instance sorting algorithms such as insertion and merge-sort and the particularly challenging quick-sort, and all usual list manipulation procedures. We have implemented our approach in a verification tool for C programs called CELIA. Automata-based approach: In [HHRSV11], we introduce a novel class of tree automata, called forest automata, that is suitable for the analysis, within the RMC approach, of heap manipulating programs with complex shapes. A heap is split into several “separated” parts such that each of them can be represented by a tree automaton, and a hierarchical representation of heaps is considered by allowing alphabets of the tree automata to contain other, nested tree automata. This approach has been implemented (by T. Vojnar’s group at TU Brno) and tested successfully on multiple non-trivial case studies, showing that it compares favorably with existing automated verification tools such as Space Invader 5. A Model Checking-based Approach for Malware Detection: Existing antivirus systems use either code emulation or signature detection. These techniques are limited since emulation-based systems can only check programs for a bounded time, whereas signature-based systems are easy to get around using obfuscation. Many of the known obfuscation techniques rely on operations on the stack such as inserting dead code by adding useless push and pop instructions, hiding calls to the operating system, etc. We propose in [ST12a; ST12c] 6 a novel approach for malware detection based on model checking that takes into account the behavior of the stack. Our approach consists in (1) modeling the program as a pushdown system, (2) using a new temporal logic, SCTPL, as a generic description language for malicious behaviors, and (3) detecting these behaviors using model-checking of pushdown systems against SCTPL. We solve this problem by a reduction to emptiness checking of Symbolic Alternating Buchi¨ Pushdown Sys- tems, for which we provide an efficient algorithm 7. We have implemented our techniques in a tool

5. J. Berdine et al.: Shape Analysis for Composite Data Structures. CAV’07, LNCS 4590. 6. [ST12c] received the EASST – Europ. Assoc. of Software Science and Technology – best paper award at ETAPS’12. 7. We extend our work in [ST11] that improves the known upper-bound for model checking pushdown systems against CTL.

235 CHAPTER 1. RESEARCH REPORT: MODELING AND VERIFICATION

(called VIDEC) that was able to automatically detect more than 400 viruses, many of which could not be detected by known antivirus systems such as Avast, Avira, and Kaspersky. Model Checking for Extended Temporal Logics: We have investigated extensions of temporal logics in order to take into account various aspects such as: Timed constraints [BCL11; BLMO07; JSL08]: We have studied in particular temporal logics allowing to express the controllability of a timed system, i.e., the fact that there exists a controller which ensures the satisfaction of some given property. Counting constraints [DDS12; LMP10a; LMP10b]: Correctness may depend from the satisfaction of tight arithmetical constraints on numbers of occurrences of events in computations. We have defined various extensions of the logics LTL and CTL with counting mechanisms, and we have investigated the complexity of their model checking problem, establishing a wide panorama, from P to undecidability. Open and multi-agent systems [BLLM09; Lar10; LLM10; LMO08]: Specifying open systems requires extending temporal logics to express the fact that a system has a strategy that ensures a property, what- ever the environment can do. We have produced several results on the expressiveness and the complexity of such logics. In particular, we have proposed an expressive extension of ATL 8 allowing to reason about complex properties on the existence of strategies for coalitions of agents. Games: We have investigated important classes of games, taking into account various aspects such as (1) higher-order stack manipulation [CHMOS08], (2) memory use in randomized strategies for infinite games [CHH09; CHH11; Hor07a; Hor07b; Hor08; HTW08], (3) stochasticity and quantitative aspects [GH08a; GH08b; GH10], and (4) fairness in 2-player games, inspired by Banach-Mazur games, and leading to a novel class of 3-player (ABM) games: We show that winning in an ABM-game (i.e. against a fair player) is equivalent to winning with probability one against the randomized adversary [ACYFV10]. Entropy of timed languages: In [AD09a; AD09b] 9, we have initiated a new research line on size, entropy and information in timed languages. For timed languages, measures of their size were defined: volume for a fixed finite number of events, and entropy (growth rate) as asymptotic measure for an unbounded number of events. These measures can be used for comparison of languages, and the entropy can be viewed as information contents of a timed language. For deterministic timed automata languages, exact formulas for volumes were given. Next, the entropy was characterized using methods of functional analysis, as a logarithm of the leading eigenvalue (spectral radius) of a positive integral operator. Several methods to compute the entropy were devised. Subsequently, the approach was extended to automata with some degeneracy [AD10a]. On the other hand, the notion of entropy helps in classical problems on languages and automata: For timed automata whose entropy is not too small most trajectories have good properties (pumping lemma, discretizability) [BA11]. To study precisely the growth of timed languages, we associate with them generating functions and investigate their properties [ABDP12]. 1.3 Scientific services, international visibility, and collaborations Scientific production: (1) Publications in renown journals (34) and major conferences 10 (>100). Three best paper awards (CIAA’08, FORMATS’09, and ETAPS’12).

(2) New tools: CELIA http://www.liafa.univ-paris-diderot.fr/celia/ (Veriﬁcation of C programs with data structures), PUMOC [ST12b] http://www.liafa.univ-paris-diderot.fr/∼song/PuMoC/ (CTL model-checker for C/C++/Java programs), and VIDEC http://www.liafa.univ-paris-diderot.fr/∼song/videc/ (Virus detector). Position of the team and collaborations: (1) The MV team is well recognized in the communities of computer aided veriﬁcation, concurrency, real-time and hybrid systems. She has several collabora-

8. R. Alur, T. Henzinger, O. Kupferman: Alternating-time Temporal Logic. JACM 49(5), 2002. 9. Paper [AD09a] received the best paper award at FORMATS’09 10. e.g., CAV, CONCUR, FORMATS, FOSSACS, FSTTCS, ICALP, LICS, MFCS, PLDI, POPL, STACS, TACAS, VMCAI.

236 CHAPTER 1. RESEARCH REPORT: MODELING AND VERIFICATION tions, nationally (VERIMAG, LaBRI, LSV, LIGM, LIP6, IRCCyN, IRISA, etc.) and internationally (U. Uppsala, TU Munich, TU Brno, U. Lubeck,¨ Microsoft Research (Redmond and India), Chennai Math Inst., U. Wisc.-Madison, IST Austria, U. Torino, U. Genoa, etc.). The team is member of the LIA Inﬁnis (Argentina), and of the LEA Struco (Czech Rep.). She is associated member of the LIA Informel (India). (2) The MV team has participated to 8 (RNTL/ANR) national collaboration projects, coordinating 4 of them. Additionally, she has participated to a COST european collaboration action, and to several bilateral collaboration projects with international teams. In the context of (RNTL/ANR) national research projects, our team has established collaborations with industrials such as EDF, and also with CEA 11. (3) Our team has 5 common works with other teams in LIAFA and PPS 12. (4) F. Laroussinie is junior member of the IUF (Institut Universitaire de France). A. Bouajjani is member of IFIP Working Group 2.2 Formal Description of Programming Concepts.

Invited contributions and stays: (1) Several invited talks in international conferences and (open/closed) workshops, e.g., FCT, LATA, VMCAI, etc. as well as in national and international schools for PhD students and young researchers: ECI (Buenos Aires), ECNU Summer School (Shanghai), ETR (Paris) FSFLA (Tarragona), InfoMath (Nancy), MOVEP (Marseille), VTSA (MPI-Saarbrucken).¨ (2) Several invited stays in international laboratories, e.g., CMI, Microsoft research (Redmond, India), Reykjavik, Stuttgart, Taipei, Tel Aviv, Uppsala, etc. (3) Two invited contributions to the Handbook of Model-Checking: A. Bouajjani and T. Touili.

Editorial and evaluation activities: (1) Membership of editorial boards of international journals, e.g., FMSD 13 (A. Bouajjani), MSCS 14 (E. Asarin), and of steering committees: FORMATS 15 (E. Asarin), MOVEP 16 (F. Laroussinie). Membership of the CAV Award committee 17 (A. Bouajjani). (2) PC-chairing of major intern. conferences of our community: CAV’09, ATVA’10 (A. Bouajjani), CAV’10 (T. Touili), CONCUR’10 (F. Laroussinie), and participation in several PC committees, e.g., CAV, CONCUR, FOSSACS, FSTTCS, HSCC, ICALP, LICS, POPL, STACS, TACAS, VMCAI, etc. (3) Participation in intern. project/institution evaluation boards (FP7-ICT FET-Open prog., DFG, ULB). (4) Participation in selection committees for professor/assist. prof. appointment in France (U. de Provence, U. Bordeaux, U. Grenoble, INP Grenoble, INRIA) and Germany (MPI). (5) Reviewing and/or membership of multiple PhD and Habilitation juries in France (ENS Cachan, U. Grenoble, U. Rennes, U. Bordeaux, U. de Provence, etc.). Reviewing PhD theses in foreign universities, e.g., TU Brno, U. Buenos Aires, U. Libre Brussels, TU Munich, U. Tel Aviv, U. Uppsala. 1.4 Internal organization and management The team: At this date, the team is composed of 12 permanent members (3 UP7 Prof., 1 UP6 Prof.- Emeritus, 6 UP7 Ass. prof. and 2 CNRS researchers), 2 post-docs, and 6 PhD students. Organization: The MV team is organized around three closely related research topics: (T1) Model checking, temporal logics and synthesis, (T2) Timed and hybrid systems, and (T3) Program veriﬁcation. The activities in these axes are headed and organized respectively by F. Laroussinie, E. Asarin, and A. Bouajjani. The number of permanent members working on each of the three topics are roughly 3, 3, and

11. CELIA implemented by our team is a plug-in of Frama-C, a platform for C program analysis developed by CEA. 12. AA [CH08a; CH08b; CHMOS08], ADG [CDGFS11], and PPS [ACYFV10]. 13. Formal Methods in System Design, Springer. This is the main journal of the CAV community. 14. Mathematical Structures in Computer Science, Cambridge Journals. 15. Intern. Conf. on Formal Modeling and Analysis of Timed Systems. 16. School for young researchers on Modeling and Verifying Parallel processes. 17. Annual award, which recognizes a fundamental contribution or a series of outstanding contributions to the CAV ﬁeld.

237 CHAPTER 1. RESEARCH REPORT: MODELING AND VERIFICATION

6 respectively. Most of the work in the team is carried out collegially within small collaborative groups. The team has a weekly seminar 18. (Talk announcements are broadly diffused in the area.) The ﬁrst goal is to attract talks by external researchers on recent work or tutorials by experts on various topics of interest. The second goal is to allow locals to expose their work and get feedback, which contributes to the communication inside the team. The ﬁrst slot of each month is reserved to a local speaker. Students are encouraged to attend doctoral schools, and members of the team are encouraged to attend at least once every year a major conference in our area such as CAV, CONCUR, ETAPS, or POPL, even if they do not have a paper to present at that event. (For instance, all students have been sent to ETAPS’12.) Students are also encouraged to visit other research groups. (For instance, Antoine Durand-Gasselin is visiting Rajeev Alur at U Penn for 4 months this year.) Students are closely supervised and encouraged to defend their theses within 3 to 4 years. Six PhD theses have been defended. Assistant professors (MdC) and researchers (CR) are encouraged to develop a research project and to present a Habilitation. Two Habilitations have been defended (P. Habermehl and T. Touili) and one is in preparation (M. Sighireanu).

Evolution of the permanent staff: In 2007 (end of previous period), Luc Boasson (Pr) and Jean- Baptiste Yunes (MdC) left MV to join AA, and Carole Delporte (MdC) and Hugues Fauconnier (MdC) moved to ADG. During 2007-12, two MdC’s left our team: Thierry Cachat who, for personal reasons, is in leave since Sept. 2008, and Antoine Meyer who got in Aug. 2009 a CNRS “chair position” and moved to LIGM at U. Marne-la-Vallee.´ In this period, our team hired one professor: Franc¸ois Laroussinie in 2007 19 and three MdC’s: Constantin Enea (T3) in 2009, Arnaud Sangnier (T1 and T3) in 2010, and Aldric Degorre (T2) in 2011. She has also hired a CNRS researcher, Florian Horn (T1 and T2) in 2009.

Post-docs: Our team had in this period six post-docs, each of whom stayed for 1 to 2 years, working on topic T3: Severine´ Fratani (now MdC at Marseille), Ahmed Rezine (now Assit. Prof. at Linkoping,¨ Sweden), Constantin Enea (MdC in the team), Roland Meyer (Junior-Prof. at Kaiserslautern, Germany), Gennaro Parlato (Lecturer at Southampton, UK), and Michael Emmi (still with us for a 3rd year).

Evolution of the scientific topics: In the last few years, our team has strengthened her activities in formal verification, and she has also developed new research directions, mainly: • A new activity has been lunched recently in T2 on the use of entropy and information theory to develop an original approach for quantitative reasoning. The current work concerns timed systems, but the approach has many potential applications: defining quality measures for abstractions, notion of approximate satisfaction, probabilistic model-checking, etc. • The activity in T3 expanded from infinite-state verification (for abstract automata-based models) to source-code program verification, leading to new contacts in other communities. While the team maintains her strong presence in conferences where she is used to publish like CAV, CON- CUR, TACAS, ICALP, FSTTCS, etc., she is also publishing in conferences of the programming languages and program analysis communities such as POPL, PLDI, ESOP, SAS, etc. In addition to partners in the model-checking community, our team has collaborations with academic researchers in the program analysis community as well as with researchers at Microsoft Research. Funding and financial management: The main funding source of the team is through its participation in ANR projects. The team got this way funding for several post-doc and PhD grants, as well as for consumables, equipment, and travels expenses. In addition, F. Laroussinie has a financial support from IUF. The management of the resources is made by the responsible of each project, in agreement with the head of the team. In normal time, (almost) every member of the team is involved in a funded project. A solidarity principle is applied within the team which consists in using, as much as possible, available resources to cover the needs of those who are not involved in a funded project.

18. http://www.liafa.univ-paris-diderot.fr/web9/manifsem/listmanifannee en.php?typecongres=4. 19. 2 professors left our team in 2003-07: P. Gastin (2004) and A. Muscholl (2006), and one joined: E. Asarin (2003).

238 Chapter 2

Fiche resum´ e:´ Modelisation´ et Veriﬁcation

Intitule´ de l’unite:´ LIAFA, UMR 7089 Directeur de l’unite:´ Pierre Fraigniaud Responable de l’equipe:´ Ahmed Bouajjani

2.1 Effectifs

2007: 1 CR CNRS, 3 PR UP7, 1 PR UP6, 8 MdC UP7, 2 post-docs, 8 doctorants 2012: 2 CR CNRS, 3 PR UP7, 1 PR-Emerite´ UP6, 6 MdC, 1 post-doc, 6 doctorants Personnels ayant quitte´ l’equipe:´ 2007: L. Boasson (PR) et J-B. Yunes (MdC) rejoignent AA, C. Del- porte (MdC) et H. Fauconnier (MdC) rejoignent ADG. 2008: T. Cachat (MdC) en detachement.´ 2009: A. Meyer (MdC) obtient une chaire CNRS au LIGM. 6 Doct. (166m), 5 PostDocs (69m). Recrutement: 2007: F. Laroussinie (PR, UP7). 2009: C. Enea (MdC, UP7) et F. Horn (CNRS CR). 2010: A. Sangnier (MdC, UP7). 2011: A. Degorre (MdC, UP7).

2.2 Production scientifique Verification´ de programmes avec structures de donnees:´ Complexite´ de problemes` sur les structures automatiques [DGH10; DGH12]. Decidabilit´ e´ de logiques pour raisonner sur des programmes manipulant un tas de memoire´ [BDES09; HIV08b]. Techniques de verification´ basees´ sur les automates/logiques/interpretation´ abstraite [BDES11; BHIKV09; HHRSV12]. Outil CELIA. Verification´ de programmes concurrents: Decidabilit´ e´ et complexite´ [ABQ11; ABT08a; Ati10a; Ati10b; BE12a]. Procedures´ efficaces de detection´ de bugs basees´ sur une sequentialisation´ composition- nelle [ABEL12; BE12b; BEP11]. Decidabilit´ e,´ complexite,´ et techniques efficaces pour la verification´ de programmes s’executant´ sur des modeles` memoire´ faibles [ABBM10; ABBM12; ABP11; BMM11]. Malware Detection: Approche basee´ sur le model checking, utilisant une logique temporelle appropriee´ pour la description des comportement malicieux, et des algorithmes efficaces de model checking pour automates a` pile (modelisant´ les programmes) [ST12a; ST12c]. Deux outils: PUMOC, un model-checker pour programmes C/C++/Java avec procedures´ [ST11; ST12b], et VIDEC, un detecteur´ de virus. Logiques temporelles et jeux: Decidabilit´ e´ et complexite´ pour des logiques temporelles etendues:´ Logiques temporisees´ [BCL11; JSL08], logiques a` compteurs [DDS12; LMP10a; LMP10b], et logiques de jeux pour raisonner sur les strategies´ et les comportements de systemes` multi-agents [BLLM09; LLM10]. Ccomplexite´ pour resoudre´ differentes´ sortes de jeux, e.g., [CHH09; CHL10; GH10]. Systemes` temporises´ et hybrides: Decidabilit´ e´ pour des classes de systemes` hybrides [AMPS12; APSY08; ASY07]. Nouvelle approche quantitative basee´ sur la definition´ de notions d’entropie et de volume de langages temporises.´ Resulats´ sur la caracterisation et le calcul de ses mesures, sur l’etude´ de la croissance de langages temporises,´ etc. [ABDP12; AD09a; AD09b; AD10a; BA11].

239 CHAPTER 2. FICHE RESUM´ E:´ MODELISATION´ ET VERIFICATION

2.3 Bilan quantitatif 2.3.1 Publications Journaux: 34 ; Conf. Int. avec CL: 101 ; W. Int. avec CL: 5 ; Conf. Int. Inv.: 3 ; Chap. ouvrages: 3. [BDES11] Ahmed Bouajjani, Cezara Dragoi, Constantin Enea, Mihaela Sighireanu. “On inter-procedural analysis of programs with lists and data.” Proceedings of the 32nd ACM SIGPLAN Conference on Programming Language Design and Implementation (PLDI’11). ACM, 2011, pp. 578–589. [HHRSV12] Peter Habermehl, Lukas´ Hol´ık, Adam Rogalewicz, Jir´ı Simacek,´ Tomas´ Vojnar. “Forest automata for verification of heap manipulation”. Formal Methods in System Design 41.1 (2012), pp. 83–106. [BE12a] Ahmed Bouajjani, Michael Emmi. “Analysis of recursively parallel programs.” Proceedings of the 39th ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages (POPL’12). ACM, 2012, pp. 203–214. [ST12c] Fu Song, Tayssir Touili. “Pushdown Model Checking for Malware Detection.” Proceedings of Tools and Algorithms for the Construction and Analysis of Systems - 18th International Conference (TACAS’12). Vol. 7214. Lecture Notes in Computer Science. Springer, 2012, pp. 110–125. [AD10a] Eugene Asarin, Aldric Degorre. “Two Size Measures for Timed Languages.” Proceedings of IARCS Annual Confer- ence on Foundations of Software Technology and Theoretical Computer Science (FSTTCS’10). Vol. 8. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2010, pp. 376–387. 2.3.2 Logiciels, brevets, rapports, etc. Habilitations a` Diriger les Recherches soutenues: − P. Habermehl, Verification´ de systemes` avec structures de donnees´ complexes a` l’aide d’automates. Dec. 2009. − T. Touili, Modelisation´ et analyse d’accessibilite´ des programmes recursifs´ concurrents. Dec. 2009. Outils: (1) CELIA : Prog. avec tas, (2) PUMOC : MC de prog. proced.,´ (3) VIDEC :Detecteur´ de virus. 2.3.3 Rayonnement 1. Membres de comites´ editoriaux´ de 5 journaux (e.g., FMSD, MSCS). Direction de comites´ de prog. de 4 confs majeures (e.g., CAV, CONCUR), participations a` des CP de confs prestigieuses. 2. Invitations a` des confs et workshops internationaux. Invitations a` des sejours´ dans labos etrangers.´ 3. 8 projets nationaux (7ANR+RNTL), 1 projet europeen´ COST coll. action (48 membres), 5 projets bilateraux´ europeen´ (Tchequie.,´ Allemagne), et 2 projets de coll. intern. (Tunisie, Russie). Implication dans 3 LIA/LEA du CNRS: Argentine, Tchequie,´ Inde. 4. F. Laroussinie est membre junior de l’Institut Universitaire de France (IUF). A. Bouajjani est membre du groupe de travail IFIP WG 2.2. Formal Description of Programming Concepts. 5. Prix du meilleur papier a` CIAA’08, FORMATS’09, et TACAS’12 (prix de l’EASST a` ETAPS’12). 2.3.4 Interactions de l’equipe´ avec son environnement 1. Direction de l’UFR informatique de UP7 (F. Laroussinie). 2. Direct. adjoint, responsabilite´ de l’informatique, de l’Ecole Doctorale “Sci. Math. Paris Centre” regroupant l’informatique de UP7, ENS Paris, et INRIA Rocquencourt (A. Bouajjani). 3. Membre CA de UP7 (2005-09), co-responsabilite´ de la Commision de Moyens (M. Sighireanu). 4. Responsabilite´ (2004-2013) du parcours professionnalisant “Logiciels Critiques” du Master Info. de UP7: Formation d’ingenieurs´ competants´ en “genie´ logiciel rigoureux”, pour entreprises dans le secteur de pointe des systemes` embarques.´ 5. Responsabilite´ (depuis 2010) du parcours Informatique de la nouvelle Ecole d’Ingenieurs´ de UP7: Formation d’ingenieurs´ en logiciel, specialis´ es´ dans les systemes` embarques.´ Appui et implication d’industriels tels que AdaCore, EADS, Trusted logics, et du CEA. 2.3.5 Actions de formation 1. Master recherche MPRI: 2 cours. ENS Paris: 1 cours. 2. Cours avances:´ Escuela de Ciencias Informaticas´ (Buenos Aires), East China National Univ. Summer School (Shanghai), Ecole Jeunes Chercheurs Info. et Math. (Nancy), Ecole Temps Reel´ (Paris), School for young researchers on MOdeling and VErification of Parallel processes (CIRM, Marseille), School on Verification Technology, Systems and Applications (MPI, Saarbrucken).¨ 3. Formation (Academie´ de Paris, IREM P7) de Prof. de Math. au lycee´ sur l’enseignement d’Info.

240 Chapter 3

Executive Summary: Modeling and Veriﬁcation

Laboratory: LIAFA, UMR 7089 Director of the laboratory: Pierre Fraigniaud Responsible of the team: Ahmed Bouajjani

3.1 Members

2007: 1 CNRS researcher, 3 PR UP7, 1 PR UP6, 8 MdC UP7, 2 post-docs, 8 PhD students 2012: 2 CNRS researchers, 3 PR UP7, 1 PR-Emeritus UP6, 6 MdC, 1 post-doc, 6 PhD students Members who left the team: 2007: L. Boasson (PR) and J-B. Yunes (MdC) moved to AA, C. Delporte (MdC) and H. Fauconnier (MdC) moved to ADG. 2008: T. Cachat (MdC) on leave. 2009: A. Meyer (MdC) got a CNRS-chair position at LIGM-UMLV. 6 PhDs (166m), 5 PostDocs (69m). Hiring: 2007: F. Laroussinie (PR, UP7). 2009: C. Enea (MdC, UP7) and F. Horn (CNRS CR). 2010: A. Sangnier (MdC, UP7). 2011: A. Degorre (MdC, UP7).

3.2 Scientific outcomes Verification of Programs with Data Structures: Complexity of decision problems on automatic structures [DGH10; DGH12]. Decidability of (graph) logics for reasoning about heap manipulating programs [BDES09; HIV08b]. Automata/logic/abstract interpretation techniques for the verification of these programs [BDES11; BHIKV09; HHRSV12]. Advanced C program verification tool CELIA. Verification of Concurrent Programs: Decidability and complexity of various verification problems [ABQ11; ABT08a; Ati10a; Ati10b; BE12a]. Powerful bug detection procedures based on compositional reduction to sequential analysis [ABEL12; BE12b; BEP11]. Decidability, complexity, and efficient techniques for verifying programs under weak memory models [ABBM10; ABBM12; ABP11; BMM11]. Malware Detection: Model checking-based approach using a suitable temporal logic for describing malicious behaviors, and efficient model checking algorithms for pushdown systems (modeling programs) [ST12a; ST12c]. Development of two novel tools: PUMOC, a (general purpose) CTL model-checker for procedural C/C++/Java programs [ST11; ST12b], and VIDEC, a virus detector. Temporal Logics and Games: Decidability and complexity of satisfiability/model checking problems for extended temporal logics: Timed logics [BCL11; JSL08], logics with counters [DDS12; LMP10a; LMP10b], and game logics for reasoning about strategies and behaviors of multi-agent systems [BLLM09; LLM10]. Complexity of solving various classes of games, e.g., [CHH09; CHL10; GH10]. Timed and hybrid systems: Decidability results for classes of hybrid systems [AMPS12; APSY08; ASY07]. Novel approach for quantitative reasoning based on the introduction of notions of entropy and volume of timed languages. Results on the characterization and the computation of these measures, on the study of the growth of times languages, etc. [ABDP12; AD09a; AD09b; AD10a; BA11].

241 CHAPTER 3. EXECUTIVE SUMMARY: MODELING AND VERIFICATION

3.3 Quantitative assessment 3.3.1 Publications Journals: 34 ; Int. Conf. with PC: 101 ; Int. W. with PC: 5 ; Inv. Int. Conf.: 3 ; Chapt. in books: 3. [BDES11] Ahmed Bouajjani, Cezara Dragoi, Constantin Enea, Mihaela Sighireanu. “On inter-procedural analysis of programs with lists and data.” Proceedings of the 32nd ACM SIGPLAN Conference on Programming Language Design and Implementation (PLDI’11). ACM, 2011, pp. 578–589. [HHRSV12] Peter Habermehl, Lukas´ Hol´ık, Adam Rogalewicz, Jir´ı Simacek,´ Tomas´ Vojnar. “Forest automata for verification of heap manipulation”. Formal Methods in System Design 41.1 (2012), pp. 83–106. [BE12a] Ahmed Bouajjani, Michael Emmi. “Analysis of recursively parallel programs.” Proceedings of the 39th ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages (POPL’12). ACM, 2012, pp. 203–214. [ST12c] Fu Song, Tayssir Touili. “Pushdown Model Checking for Malware Detection.” Proceedings of Tools and Algorithms for the Construction and Analysis of Systems - 18th International Conference (TACAS’12). Vol. 7214. Lecture Notes in Computer Science. Springer, 2012, pp. 110–125. [AD10a] Eugene Asarin, Aldric Degorre. “Two Size Measures for Timed Languages.” Proceedings of IARCS Annual Confer- ence on Foundations of Software Technology and Theoretical Computer Science (FSTTCS’10). Vol. 8. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2010, pp. 376–387. 3.3.2 Software, patents, reports, etc. Habilitations: − P. Habermehl, Verification of systems with complex data structures using automata. Dec. 2009. − T. Touili, Modeling and reachability analysis of concurrent recursive programs. Dec. 2009. Tools: (1) CELIA : Programs with heaps, (2) PUMOC : MC proced. prog., (3) VIDEC : Virus detector. 3.3.3 Influence of the team 1. Members of editorial boards of 5 journals (e.g., FMSD and MSCS). PC-chairs of 4 major intern. confs (e.g., CAV and CONCUR), numerous participations in PC committees of prestigious confs. 2. Invited talks in intern. conf., workshops, and upon-invitation-only events. Invited long-stay visits. 3. Involved in 8 national collab. projects (7ANR+RNTL), 1 COST europ. collab. action (48 members), 5 europ. bilateral coop. projects (Czech Rep., Germany), and 2 intern. bilateral coop. projects (Tunisa, Russia). Involved in 3 CNRS LIA/LEA: Argentina, Czech Rep., India. 4. F. Laroussinie is junior member of Institut Universitaire de France (IUF). A. Bouajjani is member of the IFIP Working Group 2.2. Formal Description of Programming Concepts. 5. Best paper awards at CIAA’08, FORMATS’09, and TACAS’12 (EASST award at ETAPS’12). 3.3.4 Interactions between the team and its environment 1. Director of the CS dept. (UFR informatique) of the UP7 (F. Laroussinie). 2. Deputy dir., responsible of Computer Science, of the Doctoral School “Sci. Math. Paris Centre” covering CS at UP7, ENS Paris, and INRIA Roquencourt (A. Bouajjani). 3. Admin. Council of UP7 (2005-09), co-resp. of the Funding Commission of UP7 (M. Sighireanu). 4. Responsibility (2004-13) of the professional specialization “Critical Software” of the CS master of UP7: Education of engineers with advanced skills in rigorous software engineering for high-tech companies in embedded systems and security. 5. Responsibility (since 2010) of the CS program of the new Engineering School of UP7: Education of CS engineers in software design, specialized in embedded systems. Involvement of industrials such as AdaCore, EADS, Trusted logics, and of CEA. 3.3.5 Educational activities 1. Research master MPRI: 2 courses. ENS Paris: 1 course. 2. Advanced lectures: Escuela de Ciencias Informaticas´ (Buenos Aires), East China National Univ. Summer School (Shanghai), Ecole Jeunes Chercheurs Info. et Math. (Nancy), Ecole Temps Reel´ (Paris), School for young researchers on MOdeling and VErification of Parallel processes (CIRM, Marseille), School on Verification Technology, Systems and Applications (MPI, Saarbrucken).¨ 3. Lectures and training (Paris Academy, IREM of UP7) in CS for high school Math. professors.

242 Chapter 4

Research project: Modeling and Veriﬁcation

4.1 Introduction Software verification is a major research domain, addressing issues that raise when reasoning about various classes of systems such as safety critical embedded systems as well as concurrent and distributed software, motivated in particular by the recent development of muticores and cloud computing. Indeed, as processor manufacturers reach clock-speed limits, computations are parallelized across multiple processor cores to improve performance. Moreover, due to the ubiquity of mobile devices and widespread decentralized networks, applications are executing collaboratively, distributed across a vast network of peers. These developments raise a tremendous number of problems concerning, e.g., consistency and conformance with expected behaviors, performances, security, etc. Numerous challenges must be attacked to face the complexity of these systems: New specification and verification techniques are needed for reasoning efficiently about both complex configurations and complex computations. They should lead to automatic tools allowing (1) to find bugs in programs w.r.t. various correctness criteria and classes of specifications, (2) to have substantial help in correcting these bugs, i.e., getting useful diagno- sis and (proposals for) program repairs, and (3) to establish program correctness. Moreover, quantitative reasoning is important in this context since performances and cost optimization (in terms of execution time, memory consumption, etc.) are crucial in many cases. So, verification and synthesis/program repair techniques should take into account these aspects. In the next period, our team will continue and expand her activities, addressing foundational and practical issues related to automated verification and design of software systems. Her main objectives are: 1. Extending the applicability of model checking to wider classes of systems and properties. We will consider new practically-relevant formal models and specification formalisms, and investigate their expressiveness as well as their decision problems and their complexity. In particular, we intend to investigate in depth the links between game logics (such as ATL) and quantified branching-time temporal logics, and their application in the verification of open systems. 2. Broadening and strengthening our activities on program verification. We intend: • to develop verification algorithms for concurrent and distributed programs, targeting in particular software for multicores and for cloud computing platforms. • to generalize our work on the verification of heap manipulating programs to the case of more complex heap structures (such as composite data structures), and to other types of programs (such as functional and concurrent programs). In particular, we aim at developing verification techniques and tools of libraries of concurrent and/or distributed data structures. • to extend our model checking-based approach for automatic malware detection, and to investigate other applications of advanced model checking techniques to the area of security. 3. Developing new methods for quantitative reasoning and applying them to, e.g., resource-aware analysis, probabilistic verification, performance optimization, etc. In particular, we will deepen our investigations on our recently initiated approach for entropy and information theory-based analysis of computational systems, and explore its multiple applications.

243 CHAPTER 4. RESEARCH PROJECT: MODELING AND VERIFICATION

4.2 Reasoning about complex data structures Programs can be classified with respect to the level of abstraction under which they handle memory. It is possible to identify three different levels of abstraction of dynamically allocated data-structures: Axiomatically-defined data structures that are exclusively defined and manipulated through a high-level API exhibiting simple algebraic properties. This level corresponds to programs using libraries of “containers” (vector, list, set, map, array, stack, etc.), assuming that these containers are correctly implemented. Containers libraries are available in almost all languages, e.g., STL in C++, Java Standard Collections, Ada Standard Libraries, OCaml, etc. Imperative data structures with explicit manipulation of dynamically-allocated memory: Data structures are manipulated via mutable references, pointers and statically typed records, as well as dynamic memory creation and deletion, as in languages such as Java, Ada and some (limited) dialects of C and C++. This level corresponds, e.g., to libraries of containers implementing various data-structures. Machine-level data structures which are basically imperative data-structures with additional features tightly related to the machine representation: Memory addresses can be manipulated with numerical offsets (pointer arithmetics), types cannot be fully trusted (type casts), and addresses can be accessed differently when manipulating objects of different types (unions in C or “type-punning”). C and C++ are examples of languages allowing such operations. This level corresponds to low-level programs.

This classification corresponds, roughly, to three paradigms of programming: functional, imperative and low-level programming. It is possible to identify verification techniques which pertain mostly to one of these classes, such as for instance, the use of abstract data types at the axiomatic level, versus the use of graph logics at the imperative level, or the use of modulo arithmetics at the machine level. Our aim is to develop verification algorithms and techniques that are applicable to each of the three levels described above. In the last period, our work has mainly focused on the second level (i.e., imperative programs manipulating dynamic data structures). In the next period, we intend to generalize this work and to extend it to the other (higher and lower) levels. We will address mainly the following issues:

Approximate/exact decision procedures: Besides investigating the decidability and complexity of relevant specification (automata/logic-based) formalisms, we intend developing powerful algorithms for checking satisfiability and entailment based on approximate but sound techniques that are applicable to wide classes of programs and properties (beyond known decidable classes) and that provide a good trade-off between generality, accuracy and scalability. We will define new abstract domains corresponding to different kinds of constraints, and we will define operations for their composition. We will investigate in particular techniques combining automata-based abstract representations of complex heap graphs (e.g., forest automata), with logic-based constraints on various aspects such as sizes, multisets of elements, number of occurrences of elements, arithmetical relations between elements, etc. We will also investigate combining our abstraction-based decision procedures with SMT solving techniques.

Analysis of imperative programs with composite data structures: Programs manipulate in general heaps composed of several overlapping structures sharing objects. The simplest case is the one of hierarchical data structures (such as lists of lists), where it is possible to reason about each level in isolation. However, this situation does not always hold. We intend to deﬁne abstraction methods and compositional techniques allowing to reason efﬁciently about such complex structures.

Modular analysis of functional programs with abstract data structures: We intend extending our work on inter-procedural analysis of imperative programs to the case of functional programs (and even further to higher-order programs). We will investigate summarization-based analysis techniques for these programs, and will combine them with appropriate abstract domains for reasoning about the manipulated, recursively deﬁned, data structures.

244 CHAPTER 4. RESEARCH PROJECT: MODELING AND VERIFICATION

4.3 Concurrent and distributed systems Parallelism and concurrency are present at all levels on computer systems, from distributed applications on large-scale networks, to multi-threaded software in operating systems, to low-level code for multicore hardware architectures. In the last few years, many concurrent programming languages and frameworks have appeared, providing various high-level synchronization mechanisms and task-isolating abstractions for reactive, parallel, and distributed programming, such as for instance, transactions, asynchronous programming, revisions, etc. These abstractions relieve (high-level) application programmers from error-prone handling of in- tricate task interactions by allowing to reason about interleavings of well-delimited atomic blocks that are executed in isolation. Still, nondeterminism in the execution order between these atomic blocks can make program reasoning fairly complex. At the lower level of software implementing shared-memory concurrency libraries of high-level synchronization primitives, complexity arises from relaxations of the atomicity assumptions in order to increase parallelism (using fine-grain locking and non-blocking (lock- free) techniques), which allows to improve performances while ensuring to users at the application level the notion of atomicity they expect. The correctness of non-blocking algorithms is established w.r.t. correctness criteria such as linearizability and serializability. Moreover, again for the sake of efficiency, compilers and modern multi-microprocessors may reorder certain accesses to the shared memory, implementing relaxed memory models where behaviors are not necessarily sequentially consistent (SC). Non-SC behaviors appear in presence of data races, which must be allowed in many situations, especially for implementors of synchronization operations, who must be aware of the hardware relaxations to ensure sufficient ordering guarantees, as well as for implementors of transactional memories, concurrency libraries, and other performance-critical system services, who bypass conventional locking protocols and employ lock-free synchronization techniques instead. Such programs may either be immune to the relaxations by design, or contain explicit memory ordering fences where these relaxations may have harmful effects. Applications offering services over the web are running over distributed software infrastructures. Clients of these applications typically modify and query informations stored in distributed data structures, the latter being replicated in different locations of the network in order to ensure information availability to the users. Ideally, all replicas must see the same sequence of updates. However, this would require permanent synchronizations through the network, which is unfeasible. Consequently, a weaker consistency model, called eventual consistency is adopted, ensuring that all replicas eventually see all updates and converge to the same configuration. At the higher level, abstraction mechanisms such as (distributed) transactions can be provided to application programmers. Then, assuming coherence models such as eventual consistency for update management, the implementation of these mechanisms must ensure correctness criteria such as serializability, or the weaker snapshot isolation or causal consistency that are often adopted in this context for performance reasons. Our aim in the next period is, being permanently guided by the current trends in the design of reactive, parallel, and distributed programming languages and systems, to develop advanced methods for automatic verification of concurrent and distributed software, targeting important classes of systems such as concurrent software running on multicores, and distributed software for cloud computing platforms. We will develop verification techniques that are applicable to various kind of concurrent software, at different levels of the software stack, taking into account various concurrency paradigms and synchronization mechanisms, as well as various practically-relevant memory models and correctness criteria. Furthermore, we intend to develop methods and tools for automatic synthesis of synchronization actions (e.g., locking actions, memory fences) in order to correct concurrency bugs. These methods must take into account the performance penalty associated with a bug fix (as an additional lock or fence may have an important impact on the performances), and propose optimal repairs. We will address mainly:

245 CHAPTER 4. RESEARCH PROJECT: MODELING AND VERIFICATION

Models for concurrent programs and their verification problems: We will pursue our investigations on formal models corresponding to significant classes of concurrent/distributed programs. There is a variety of (continuously emerging) programming patterns/languages used in multicore software programming and in cloud computing. It is important to understand the basic formal models behind these patterns and languages, to study in depth the complexity of verification problems for these models, and to develop efficient techniques and tools for their analysis.

Verifying correctness of libraries of concurrent and distributed data structures: We will investigate the decidability and the complexity of checking correctness criteria such as linearizability, serializability, snapshot isolation, eventual consistency, etc., taking into account various unbounded parameters such as the size of the dynamic data structures, the number of threads, the size of the network, etc. Be- yond the decidability issues, our aim is to develop efficient algorithmic techniques for these verification problems based on on-the-fly behavior exploration techniques, and efficient symbolic representations of concrete/abstract program configurations.

Verifying programs under weak memory models: We will investigate fundamental issues related to the decidability and the complexity of verification problems, such as satisfaction of safety/liveness properties, under realistic and complex weak memory models such as Power and ARM for hardware, and the C++ memory model. Since we have shown that basic problems such as reachability are highly complex even for (the strongest weak memory model) TSO, an important issue is to develop scalable algorithmic verification techniques allowing to check program assertions either by detecting violations using under-approximate analysis, generalizing for instance the promising approach we introduced in [ABP11], or by establishing their validity using adequate abstraction techniques. We will also investigate the issue of checking program robustness against weak memory models such as those mentioned above. The limits of decidability, and the complexity, of the robustness problem are unknown beyond TSO (for which we have established that it is PSPACE-complete). Our aim is to explore and draw precisely the decidability frontier, and to characterize the class of models for which robustness checking is PSPACE-complete and can be effectively reduced to state-reachability checking under SC (allowing the use in this context of state-of-the-art verification tools for concurrent programs).

Synchronization synthesis and fence insertion: Based on the verification algorithms mentioned above, we intend developing efficient techniques for automatic repair of concurrency bugs by inserting necessary synchronization actions (such as locks or CAS actions) and memory fences. These techniques should synthesize a set of synchronization actions, inserted at appropriate program locations, in order to enforce correctness. A minimal requirement from the program repair is irreducibility, i.e., minimal w.r.t. set inclusion. Other optimality criteria taking into account performances, must be investigated. 4.4 Malware detection Malware detection is an important, highly challenging problem. Classical virus detection techniques such as signature-based detection have serious limitations. In particular, virus writers use obfuscation (such as dead-code insertion and register reassignment) and frequently update their viruses to make them undetectable by these antivirus systems. To overcome these limitations, we proposed recently a novel and quite powerful approach for automatic malware detection based on model checking. We intend to develop this promising approach in the following ways: • We will enlarge our capabilities of characterizing malicious behaviors. In particular, we will address the cases of self modifying malware (i.e. malicious codes which mutate their own code whenever they propagate), and of distributed web malware that exploit vulnerabilities in the web infrastructure. For that, we will extend our approach by defining appropriate models for representing the behaviors of the analyzed programs (that can be sequential, concurrent, or distributed), and expressive logics for compact description of malicious behaviors of various families of malware.

246 CHAPTER 4. RESEARCH PROJECT: MODELING AND VERIFICATION

• We will design efficient malware detection algorithms based on model checking techniques for the considered program models and malware specification logics. In particular, we will investigate adequate abstraction and symbolic techniques allowing to improve scalability. 4.5 Quantitative Reasoning Estimating resource consumption: Computing bounds on the amount of resource used by a program is a problem of the highest importance in software design in a variety of domains, ranging from embedded systems to cloud computing. Critical resources can be, e.g., execution time, memory, power, bandwidth, etc. A crucial issue is to characterize a worst-case bound on the resource consumption of a program as a function of its input parameters. It is a difficult problem due to complex control structures such as nested loops, recursion, etc, as well as to complex data and heap manipulations. It is important to provide good approximations of consumption-bound functions that can be quite complex (polynomials, exponentials, etc.). We will investigate the extension of our program analysis techniques to this problem. In particular, we intend 1 to define (1) abstract domains for reasoning about various kind of measures, and (2) analysis procedures using these abstract domains able to generate consumption-bounds functions. Entropy and quantitative analysis: We will continue our investigations on entropy/information theory-based analysis for models of computational systems. This analysis will lead to a substantial progress in three directions which constitute three facets of the main objectives of our project: Theoretical study of entropy in new classes of dynamical systems: We aim to obtain important theoretical contributions concerning entropy of (generalized) dynamical systems associated to transducers, games, timed and cellular automata etc. Implications on conjugacy and expressiveness problems, as well as relations to other information measures, such as Kolmogorov complexity, will be addressed. Study of information processes in computational systems: It is a commonplace that computational systems process and transmit information. In this project we will measure the quantity of information circulating in or generated by such systems. This would shed new light on computational systems, and provide new tools to assess computer security and performance of communication protocols, and new approaches to data compression. Quantitative analysis and quantitative verification of computational systems: We believe that, com- pared to more usual probability-based approaches, entropy methods have two important advantages: they do not require exact knowledge of probabilities of all the events in the system, and they can be much easier to implement.

The concepts and the techniques developed during this work will be useful for adjacent areas of computer science, especially theory of automata and formal languages, and probabilistic veriﬁcation. We intend to investigate their use in deﬁning adequate measures for the quality of an implementation w.r.t. a correctness criterion. This is important, e.g., in resource/performance-aware program repair/synthesis.

4.6 Implementation of the project Manpower: The project is a continuation of the present activities of the team, addressing topics where the team has strong expertise, and expanding to adjacent topics in a natural way. The team has a wide network of collaborators. Though, the following issues must be addressed during the next period: • The team has developed in the last few years a strong activity on the veriﬁcation of formal models for concurrent programs, and more recently on source-code concurrent programs. However, in the last cou- ple of years, the main manpower on this research topic was constituted by post-docs and PhD students. (T. Touili, who contributed a lot to this topic, shifted recently her main interests to the topic of malware detection and security.) Although, we are keeping active collaboration with these former members of our

1. Work in collaboration with Diego Garbervetsky and Sergio Yovine from U. Buenos Aires in the frame of LIA Inﬁnis.

247 CHAPTER 4. RESEARCH PROJECT: MODELING AND VERIFICATION team, maintaining in our team a strong and expanding activity on the topic of concurrent and distributed program verification requires recruiting young permanent members. • So far, the development of verification tools is our team has been done mainly by Mihaela Sighireanu, with help of students, e.g., Cezara Dragoi during her PhD thesis. This task constitutes a huge, time con- suming effort, especially that Mihaela has also teaching obligations. It is crucial to strengthen our team by other members who have a balanced profile combining strong skills in both theoretical and practical aspects, and who are able to conduct a research activity related to software development. • Members playing key roles in our team such as Peter Habermehl and Mihaela Sighireanu have good chances to get promoted in the next few years as Professors in other institutions. However, both Peter and Mihaela are now essential contributors to the topic of infinite-state verification, decision procedures, and verification programs with data structures. Moreover, as mentioned above, Mihaela is our main person in tool development. Therefore, the move of these two members will be an important lost that our team will need to compensate by recruiting young talented members for their replacement. • Malware detection and security is a recent, important research direction in our team that we want to develop. For that, we need to strengthen the group working on this direction, by recruiting post-docs and students in the short term, and a young permanent member within the next 4/5 years. • Our team lacks full-time permanent researchers. We will continue our efforts for attracting excellent candidates, hoping that CNRS will eventually consider helping our team. • In general, our team will need to recruit post-docs in replacement of those who left the team recently (and who contributed a lot to her achievements), and to increase the number of her PhD students orig- inating both from the research master MPRI and from foreign institutions. We hope that we will get financial support (from ANR, Fond. Sci. Math. de Paris, etc.) for that. Financial resources: • The work concerning entropy and information-based analysis of computational systems is carried out in the framework of a new 4-year ANR project EQINOCS coordinated by Eugene` Asarin, in collaboration with LIGM (Marne La-Vallee),´ LACL (Paris 12) and VERIMAG (Grenoble). • Currently, our team is participating to two other ANR projects Veridyc (program verification) and ImpRo (timed systems). We intend submitting next year funding applications for continuations of the Veridyc project: (1) Verification of multicore software, and (2) Decision procedures and analysis techniques for the verification of programs manipulating data structures. • In addition to ANR project applications, we are participating to the definition of a european project on the verification multicore software (with partners such as Uppsala university, ETH Zurich, etc.) • We will also encourage our young researchers to apply to ERC starting grants on topics such as verification of distributed data structures, and multiware detection. New collaborations: We will develop several recently established contacts in our environment, e.g.: • Open-source software deployment: We are defining a collaboration project with Ralf Treinen and Roberto Di Cosmo (INRIA-PPS) on the verification of Unix Scripts, that are programs interacting with the OS used, e.g., for maintaining (installing, removing, upgrading) software packages. • Programs with data structures: We are defining a collaboration project with the AdaCore company (e.g., Yannick Moy) on the verification of programs with complex data structures. • Weak memory models: We intend defining a collaboration project with Luc Maranget (INRIA) on formal modeling and automatic verification of hardware weak memory models. • Distributed algorithms, distributed data structures: We have initiated discussions with Marc Shapiro (INRIA-LIP6) on replicated, distributed data structures. Our aim is to understand semantical issues related to the design of such data structures in order to develop verification methods for their implementations. We also intend collaborating with the ADG team on the verification of distributed algorithms. (Notice that we have produced recently a common publication [CDGFS11]). • Higher-order functional programs: We intend interacting with the AA team (e.g., Olivier Serre) on the verification of higher-order functional programs, especially in the case of data manipulating programs.

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INTERNAL

• • Funding mainly based on ANR Lack of permanent assist. staff on concurrent/distributed • program veriﬁcation Number of CNRS researchers

Cohesion of the team, • coherent set of research topics Strong expertise, Weakness • complementary skills Mainstream topics • in CAV and PL ﬁelds

Strength NEGATIVE Balance theory/applications • S W

• O T POSITIVE • Large collaborationOpportunity network • Participation in 3 LIA/LEA Many emerging topics: Quantitative reasoning, Malware detection, Threat Multicores, Cloud computing, Software deployment

Departure, non replacement • of key members Funding cuts • Load due to administrative tasks • e.g., Dir. of CS depart. (UFR)

EXTERNAL

Figure 4.1: SWOT analysis of the scientiﬁc project

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250 Chapter 5

List of publications: Modeling and Veriﬁcation

ACL : Articles in international or national journals

[ABd08] Parosh Aziz Abdulla, Ahmed Bouajjani, Julien d’Orso. “Monotonic and Downward Closed Games.” J. Log. Comput. 18.1 (2008), pp. 153–169. [ABHKV09] Parosh Aziz Abdulla, Ahmed Bouajjani, Lukas´ Hol´ık, Lisa Kaati, Tomas´ Vojnar. “Com- posed Bisimulation for Tree Automata.” Int. J. Found. Comput. Sci. 20.4 (2009), pp. 685– 700. [ABQ11] Mohamed Faouzi Atig, Ahmed Bouajjani, Shaz Qadeer. “Context-Bounded Analysis For Concurrent Programs With Dynamic Creation of Threads”. Logical Methods in Computer Science 7.4 (2011). [AD10b] Eugene Asarin, Catalin Dima. “On the computation of covert channel capacity.” RAIRO - Theor. Inf. and Applic. 44.1 (2010), pp. 37–58. [ADG07] Eugene Asarin, Thao Dang, Antoine Girard. “Hybridization methods for the analysis of nonlinear systems.” Acta Inf. 43.7 (2007), pp. 451–476. [ADHR09] Parosh Aziz Abdulla, Giorgio Delzanno, Noomene Ben Henda, Ahmed Rezine. “Mono- tonic Abstraction: on Efficient Verification of Parameterized Systems.” Int. J. Found. Com- put. Sci. 20.5 (2009), pp. 779–801. [ADR09b] Parosh Aziz Abdulla, Giorgio Delzanno, Ahmed Rezine. “Approximated parameterized verification of infinite-state processes with global conditions.” Formal Methods in System Design 34.2 (2009), pp. 126–156. [AH11] Mohamed Faouzi Atig, Peter Habermehl. “On Yen’s Path Logic for Petri Nets.” Int. J. Found. Comput. Sci. 22.4 (2011), pp. 783–799. [AMPS12] Eugene Asarin, Venkatesh Mysore, Amir Pnueli, Gerardo Schneider. “Low dimensional hybrid systems - decidable, undecidable, don’t know.” Inf. Comput. 211 (2012), pp. 138– 159. [APSY08] Eugene Asarin, Gordon J. Pace, Gerardo Schneider, Sergio Yovine. “Algorithmic analysis of polygonal hybrid systems, Part II: Phase portrait and tools.” Theor. Comput. Sci. 390.1 (2008), pp. 1–26. [ASY07] Eugene Asarin, Gerardo Schneider, Sergio Yovine. “Algorithmic analysis of polygonal hybrid systems, part I: Reachability.” Theor. Comput. Sci. 379.1-2 (2007), pp. 231–265. [BBHIMV11] Ahmed Bouajjani, Marius Bozga, Peter Habermehl, Radu Iosif, Pierre Moro, Tomas´ Vojnar. “Programs with lists are counter automata.” Formal Methods in System Design 38.2 (2011), pp. 158–192.

251 CHAPTER 5. LIST OF PUBLICATIONS: MODELING AND VERIFICATION

[BCL11] Patricia Bouyer, Franck Cassez, François Laroussinie. “Timed Modal Logics for Real- Time Systems - Specification, Verification and Control.” Journal of Logic, Language and Information 20.2 (2011), pp. 169–203. [BDEJS09] Ahmed Bouajjani, Cezara Dragoi, Constantin Enea, Yan Jurski, Mihaela Sighireanu. “A Generic Framework for Reasoning about Dynamic Networks of Infinite-State Processes”. Logical Methods in Computer Science 5.2 (2009). [BHRV12] Ahmed Bouajjani, Peter Habermehl, Adam Rogalewicz, Tomas´ Vojnar. “Abstract regular (tree) model checking.” STTT 14.2 (2012), pp. 167–191. [BHV08] Ahmed Bouajjani, Peter Habermehl, Tomas´ Vojnar. “Verification of parametric concurrent systems with prioritised FIFO resource management.” Formal Methods in System Design 32.2 (2008), pp. 129–172. [BMT07] Ahmed Bouajjani, Anca Muscholl, Tayssir Touili. “Permutation rewriting and algorithmic verification.” Inf. Comput. 205.2 (2007), pp. 199–224. [BT12] Ahmed Bouajjani, Tayssir Touili. “Widening techniques for regular tree model checking.” STTT 14.2 (2012), pp. 145–165. [CGM08] Patrick Cegielski,´ Irene` Guessarian, Yuri Matiyasevich. “Tree inclusion problems.” ITA 42.1 (2008), pp. 5–20. [CHH09] Krishnendu Chatterjee, Thomas A. Henzinger, Florian Horn. “Finitary winning in omega- regular games.” ACM Trans. Comput. Log. 11.1 (2009). [DDHL11] Ajoy Kumar Datta, Stephane´ Devismes, Florian Horn, Lawrence L. Larmore. “Self- Stabilizing k-out-of-l Exclusion in Tree Networks.” Int. J. Found. Comput. Sci. 22.3 (2011), pp. 657–677. [FG09] Eugenie´ Foustoucos, Irene` Guessarian. “Inf-datalog, Modal Logic and Complexities.” ITA 43.1 (2009), pp. 1–21. [GDE11] Dimitar P. Guelev, Catalin Dima, Constantin Enea. “An alternating-time temporal logic with knowledge, perfect recall and past: axiomatisation and model-checking.” Journal of Applied Non-Classical Logics 21.1 (2011), pp. 93–131. [HHRSV12] Peter Habermehl, Lukas´ Hol´ık, Adam Rogalewicz, Jir´ı Simacek,´ Tomas´ Vojnar. “Forest automata for verification of heap manipulation”. Formal Methods in System Design 41.1 (2012), pp. 83–106. [HIV10] Peter Habermehl, Radu Iosif, Tomas´ Vojnar. “Automata-based verification of programs with tree updates.” Acta Inf. 47.1 (2010), pp. 1–31. [Hor07a] Florian Horn. “Dicing on the Streett.” Inf. Process. Lett. 104.1 (2007), pp. 1–9. [JSL08] Marcin Jurdzinski, Jeremy Sproston, François Laroussinie. “Model Checking Probabilistic Timed Automata with One or Two Clocks.” Logical Methods in Computer Science 4.3 (2008). [KLTR11] Nicholas Kidd, Peter Lammich, Tayssir Touili, Thomas W. Reps. “A decision procedure for detecting atomicity violations for communicating processes with locks.” STTT 13.1 (2011), pp. 37–60. [Lar10] François Laroussinie. “Temporal Logics for Games.” Bulletin of the EATCS 100 (2010), pp. 79–98. [LMO08] François Laroussinie, Nicolas Markey, Ghassan Oreiby. “On the Expressiveness and Com- plexity of ATL.” Logical Methods in Computer Science 4.2 (2008). [Mey08] Antoine Meyer. “Traces of term-automatic graphs.” ITA 42.3 (2008), pp. 615–630.

252 CHAPTER 5. LIST OF PUBLICATIONS: MODELING AND VERIFICATION

[TA10] Tayssir Touili, Mohamed Faouzi Atig. “Verifying parallel programs with dynamic communication structures.” Theor. Comput. Sci. 411.38-39 (2010), pp. 3460–3468. [Tou12b] Tayssir Touili. “Computing transitive closures of hedge transformations.” IJCCBS 3.1/2 (2012), pp. 132–150. [YRSMB07] Greta Yorsh, Alexander Moshe Rabinovich, Mooly Sagiv, Antoine Meyer, Ahmed Bouajjani. “A logic of reachable patterns in linked data-structures.” J. Log. Algebr. Program. 73.1-2 (2007), pp. 111–142.

C-INV : Invited talks/papers in international conferences and workshops

[AB09] Mohamed Faouzi Atig, Ahmed Bouajjani. “On the Reachability Problem for Dynamic Networks of Concurrent Pushdown Systems.” Proceedings of Reachability Problems - 3rd International Workshop (RP’09). Vol. 5797. Lecture Notes in Computer Science. Springer, 2009, pp. 1–2. [Asa12] Eugene Asarin. “Measuring Information in Timed Languages.” Proceedings of Lan- guage and Automata Theory and Applications - 6th International Conference (LATA’12). Vol. 7183. Lecture Notes in Computer Science. Springer, 2012, pp. 1–2. [BDES12] Ahmed Bouajjani, Cezara Dragoi, Constantin Enea, Mihaela Sighireanu. “Abstract Do- mains for Automated Reasoning about List-Manipulating Programs with Infinite Data.” Proceedings of Verification, Model Checking, and Abstract Interpretation - 13th Interna- tional Conference (VMCAI’12). Vol. 7148. Lecture Notes in Computer Science. Springer, 2012, pp. 1–22. [BHJS07] Ahmed Bouajjani, Peter Habermehl, Yan Jurski, Mihaela Sighireanu. “Rewriting Systems with Data.” Proceedings of Fundamentals of Computation Theory - 16th International Symposium (FCT’07). Vol. 4639. Lecture Notes in Computer Science. Springer, 2007, pp. 1–22. [Bou07a] Ahmed Bouajjani. “Automata-based techniques for shape analysis”. International Sympo- sium on Automatic Heap Analysis (AHA 2007). 2007. [Bou07b] Ahmed Bouajjani. “Automata-based techniques for the Verification of Programs with Linked Data Structures”. International Workshop on Heap Analysis and Verification (HAV 2007). 2007. [Bou08] Ahmed Bouajjani. “Rewriting systems with data: a framework for reasoning about unbounded networks of infinite-state processes”. International Workshop on Rewriting Logic and its Applications (WRLA 2008). 2008. [Bou12] Ahmed Bouajjani. “Checking state reachability for weak memory models”. International Workshop on Memory Consistency Models (REORDER 2012). 2012. [Lar07] François Laroussinie. “Alternating-time Temporal Logic: Expressivity, Complexity, Ex- tensions”. International Workshop on Expressiveness in Concurrency (EXPRESS 2007). 2007.

C-ACTI : International conference proceedings

Publications [CH08a; CH08b; CHMOS08] are joint with the AA team, publication [CDGFS11] is joint with the ADG team, and publication [ACYFV10] is joint with PPS laboratory.

253 CHAPTER 5. LIST OF PUBLICATIONS: MODELING AND VERIFICATION

[AAGILS07] Yasmina Abdedda¨ım, Eugene Asarin, Matthieu Gallien, Felix´ Ingrand, Charles Lesire, Mihaela Sighireanu. “Planning Robust Temporal Plans: A Comparison Between CBTP and TGA Approaches.” Proceedings of the Seventeenth International Conference on Au- tomated Planning and Scheduling (ICAPS’07). AAAI, 2007, pp. 2–9. [AAS09] Yasmina Abdedda¨ım, Eugene Asarin, Mihaela Sighireanu. “Simple Algorithm for Simple Timed Games.” Proceedings of the 16th International Symposium on Temporal Represen- tation and Reasoning (TIME’09). IEEE Computer Society, 2009, pp. 99–106. [ABBDP12] Eugene Asarin, Nicolas Basset, Marie-Pierre Beal,´ Aldric Degorre, Dominique Perrin. “Toward Timed Theory of Codes.” Proceedings of Formal Modeling and Analysis of Timed Systems - 10th International Conference (FORMATS’12). Lecture Notes in Computer Sci- ence. Springer, 2012. [ABBM10] Mohamed Faouzi Atig, Ahmed Bouajjani, Sebastian Burckhardt, Madanlal Musuvathi. “On the verification problem for weak memory models.” Proceedings of the 37th ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages (POPL’10). ACM, 2010, pp. 7–18. [ABBM12] Mohamed Faouzi Atig, Ahmed Bouajjani, Sebastian Burckhardt, Madanlal Musuvathi. “What’s Decidable about Weak Memory Models?” Proceedings of Programming Lan- guages and Systems - 21st European Symposium on Programming (ESOP’12). Vol. 7211. Lecture Notes in Computer Science. Springer, 2012, pp. 26–46. [ABCHR08] Parosh Aziz Abdulla, Ahmed Bouajjani, Jonathan Cederberg, Fred´ eric´ Haziza, Ahmed Rezine. “Monotonic Abstraction for Programs with Dynamic Memory Heaps.” Proceedings of Computer Aided Verification - 20th International Conference (CAV’08). Vol. 5123. Lecture Notes in Computer Science. Springer, 2008, pp. 341–354. [ABDP12] Eugene Asarin, Nicolas Basset, Aldric Degorre, Dominique Perrin. “Generating Functions of Timed Languages.” Mathematical Foundations of Computer Science - 37th Interna- tional Symposium (MFCS’12). Lecture Notes in Computer Science. Springer, 2012. [ABEL12] Mohamed Faouzi Atig, Ahmed Bouajjani, Michael Emmi, Akash Lal. “Detecting Fair Non-termination in Multithreaded Programs”. Proceedings of Computer Aided Verifica- tion - 24th International Conference (CAV 2012). Vol. 7358. Lecture Notes in Computer Science. Springer, 2012, pp. 210–226. [ABH08] Mohamed Faouzi Atig, Benedikt Bollig, Peter Habermehl. “Emptiness of Multi-pushdown Automata Is 2ETIME-Complete.” Proceedings of Developments in Language Theory - 12th International Conference (DLT’08). Vol. 5257. Lecture Notes in Computer Science. Springer, 2008, pp. 121–133. [ABHKV08a] Parosh Aziz Abdulla, Ahmed Bouajjani, Lukas´ Hol´ık, Lisa Kaati, Tomas´ Vojnar. “Com- posed Bisimulation for Tree Automata.” Proceedings of Implementation and Applications of Automata - 13th International Conference (CIAA’08). Vol. 5148. Lecture Notes in Com- puter Science. Springer, 2008, pp. 212–222. [ABHKV08b] Parosh Aziz Abdulla, Ahmed Bouajjani, Lukas´ Hol´ık, Lisa Kaati, Tomas´ Vojnar. “Computing Simulations over Tree Automata.” Proceedings of Tools and Algorithms for the Construction and Analysis of Systems - 14th International Conference (TACAS’08). Vol. 4963. Lecture Notes in Computer Science. Springer, 2008, pp. 93–108. [ABKS12] Mohamed Faouzi Atig, Ahmed Bouajjani, K. Narayan Kumar, Prakash Saivasan. “Linear- Time Model-Checking for Multithreaded Programs under Scope-Bounding”. Proceedings of the 10th International Symposium on Automated Technology for Verification and Anal- ysis (ATVA 2012). Vol. 7561. Lecture Notes in Computer Science. Springer, 2012.

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[ABP11] Mohamed Faouzi Atig, Ahmed Bouajjani, Gennaro Parlato. “Getting Rid of Store-Buffers in TSO Analysis.” Proceedings of Computer Aided Verification - 23rd International Con- ference (CAV’11). Vol. 6806. Lecture Notes in Computer Science. Springer, 2011, pp. 99– 115. [ABQ09] Mohamed Faouzi Atig, Ahmed Bouajjani, Shaz Qadeer. “Context-Bounded Analysis for Concurrent Programs with Dynamic Creation of Threads.” Proceedings of Tools and Al- gorithms for the Construction and Analysis of Systems - 15th International Conference (TACAS’09). Vol. 5505. Lecture Notes in Computer Science. Springer, 2009, pp. 107–123. [ABT08a] Mohamed Faouzi Atig, Ahmed Bouajjani, Tayssir Touili. “Analyzing Asynchronous Pro- grams with Preemption.” Proceedings of IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS’08). Vol. 2. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2008, pp. 37–48. [ABT08b] Mohamed Faouzi Atig, Ahmed Bouajjani, Tayssir Touili. “On the Reachability Analysis of Acyclic Networks of Pushdown Systems.” Proceedings of Concurrency Theory - 19th International Conference (CONCUR’08). Vol. 5201. Lecture Notes in Computer Science. Springer, 2008, pp. 356–371. [ACSTL07] Eugene Asarin, Thierry Cachat, Alexander Seliverstov, Tayssir Touili, Vassily A. Lyubet- sky. “Attenuation Regulation as a Term Rewriting System.” Proceedings of Algebraic Bi- ology, Second International Conference (AB’07). Vol. 4545. Lecture Notes in Computer Science. Springer, 2007, pp. 81–94. [ACYFV10] Eugene Asarin, Raphael¨ Chane-Yack-Fa, Daniele Varacca. “Fair Adversaries and Ran- domization in Two-Player Games.” Proceedings of Foundations of Software Science and Computational Structures - 13th International Conference (FOSSACS’10). Vol. 6014. Lec- ture Notes in Computer Science. Springer, 2010, pp. 64–78. [AD09a] Eugene Asarin, Aldric Degorre. “Volume and Entropy of Regular Timed Languages: An- alytic Approach.” Proceedings of Formal Modeling and Analysis of Timed Systems - 7th International Conference (FORMATS’09). Vol. 5813. Lecture Notes in Computer Science. Springer, 2009, pp. 13–27. [AD09b] Eugene Asarin, Aldric Degorre. “Volume and Entropy of Regular Timed Languages: Dis- cretization Approach.” Proceedings of Concurrency Theory - 20th International Con- ference (CONCUR’09). Vol. 5710. Lecture Notes in Computer Science. Springer, 2009, pp. 69–83. [AD10a] Eugene Asarin, Aldric Degorre. “Two Size Measures for Timed Languages.” Proceedings of IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS’10). Vol. 8. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2010, pp. 376–387. [ADMN12] Eugene Asarin, Alexandre Donze,´ Oded Maler, Dejan Nickovic. “Parametric Identifica- tion of Temporal Properties.” Proceedings of Runtime Verification - 2nd International Con- ference (RV’11). Vol. 7186. Lecture Notes in Computer Science. Springer, 2012. [ADMT10] Eugene Asarin, Thao Dang, Oded Maler, Romain Testylier. “Using Redundant Con- straints for Refinement.” Proceedings of Automated Technology for Verification and Anal- ysis - 8th International Symposium (ATVA’10). Vol. 6252. Lecture Notes in Computer Sci- ence. Springer, 2010, pp. 37–51.

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[ADR09a] Parosh Aziz Abdulla, Giorgio Delzanno, Ahmed Rezine. “Approximated Context- Sensitive Analysis for Parameterized Verification.” Proceedings of Formal Techniques for Distributed Systems - Joint 11th IFIP WG 6.1 International Conference (FMOODS’09) and 29th IFIP WG 6.1 International Conference (FORTE’09). Vol. 5522. Lecture Notes in Computer Science. Springer, 2009, pp. 41–56. [ADR09c] Parosh Aziz Abdulla, Giorgio Delzanno, Ahmed Rezine. “Automatic Verification of Directory-Based Consistency Protocols.” Proceedings of Reachability Problems - 3rd In- ternational Workshop (RP’09). Vol. 5797. Lecture Notes in Computer Science. Springer, 2009, pp. 36–50. [ADRST11] Parosh Aziz Abdulla, Giorgio Delzanno, Othmane Rezine, Arnaud Sangnier, Riccardo Traverso. “On the Verification of Timed Ad Hoc Networks.” Proceedings of Formal Mod- eling and Analysis of Timed Systems - 9th International Conference (FORMATS’11). Vol. 6919. Lecture Notes in Computer Science. Springer, 2011, pp. 256–270. [AH09] Mohamed Faouzi Atig, Peter Habermehl. “On Yen’s Path Logic for Petri Nets.” Proceed- ings of Reachability Problems - 3rd International Workshop (RP’09). Vol. 5797. Lecture Notes in Computer Science. Springer, 2009, pp. 51–63. [AT09] Mohamed Faouzi Atig, Tayssir Touili. “Verifying Parallel Programs with Dynamic Com- munication Structures.” Proceedings of Implementation and Applications of Automata - 14th International Conference (CIAA’09). Vol. 5642. Lecture Notes in Computer Science. Springer, 2009, pp. 145–154. [Ati10a] Mohamed Faouzi Atig. “From Multi to Single Stack Automata.” Proceedings of Concur- rency Theory - 21th International Conference (CONCUR’10). Vol. 6269. Lecture Notes in Computer Science. Springer, 2010, pp. 117–131. [Ati10b] Mohamed Faouzi Atig. “Global Model Checking of Ordered Multi-Pushdown Systems.” Proceedings of IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS’10). Vol. 8. LIPIcs. Schloss Dagstuhl - Leibniz- Zentrum fuer Informatik, 2010, pp. 216–227. [BA11] Nicolas Basset, Eugene Asarin. “Thin and Thick Timed Regular Languages.” Proceedings of Formal Modeling and Analysis of Timed Systems - 9th International Conference (FOR- MATS’11). Vol. 6919. Lecture Notes in Computer Science. Springer, 2011, pp. 113–128. [BDERS10] Ahmed Bouajjani, Cezara Dragoi, Constantin Enea, Ahmed Rezine, Mihaela Sighireanu. “Invariant Synthesis for Programs Manipulating Lists with Unbounded Data.” Proceed- ings of Computer Aided Verification - 22nd International Conference (CAV’10). Vol. 6174. Lecture Notes in Computer Science. Springer, 2010, pp. 72–88. [BDES09] Ahmed Bouajjani, Cezara Dragoi, Constantin Enea, Mihaela Sighireanu. “A Logic-Based Framework for Reasoning about Composite Data Structures.” Proceedings of Concurrency Theory - 20th International Conference (CONCUR’09). Vol. 5710. Lecture Notes in Com- puter Science. Springer, 2009, pp. 178–195. [BDES11] Ahmed Bouajjani, Cezara Dragoi, Constantin Enea, Mihaela Sighireanu. “On inter- procedural analysis of programs with lists and data.” Proceedings of the 32nd ACM SIG- PLAN Conference on Programming Language Design and Implementation (PLDI’11). ACM, 2011, pp. 578–589. [BDKSS12] Nathalie Bertrand, Giorgio Delzanno, Barbara Konig,¨ Arnaud Sangnier, Jan Stuckrath.¨ “On the Decidability Status of Reachability and Coverability in Graph Transformation Sys- tems”. RTA. Vol. 15. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2012, pp. 101–116.

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[BE12a] Ahmed Bouajjani, Michael Emmi. “Analysis of recursively parallel programs.” Proceed- ings of the 39th ACM SIGPLAN-SIGACT Symposium on Principles of Programming Lan- guages (POPL’12). ACM, 2012, pp. 203–214. [BE12b] Ahmed Bouajjani, Michael Emmi. “Bounded Phase Analysis of Message-Passing Pro- grams.” Proceedings of Tools and Algorithms for the Construction and Analysis of Sys- tems - 18th International Conference (TACAS’12). Vol. 7214. Lecture Notes in Computer Science. Springer, 2012, pp. 451–465. [BEP11] Ahmed Bouajjani, Michael Emmi, Gennaro Parlato. “On Sequentializing Concurrent Pro- grams.” Proceedings of Static Analysis - 18th International Symposium (SAS’11). Vol. 6887. Lecture Notes in Computer Science. Springer, 2011, pp. 129–145. [BESS08] Ahmed Bouajjani, Javier Esparza, Stefan Schwoon, Dejvuth Suwimonteerabuth. “SD- SIrep: A Reputation System Based on SDSI.” Proceedings of Tools and Algorithms for the Construction and Analysis of Systems - 14th International Conference (TACAS’08). Vol. 4963. Lecture Notes in Computer Science. Springer, 2008, pp. 501–516. [BFQ07] Ahmed Bouajjani, Severine´ Fratani, Shaz Qadeer. “Context-Bounded Analysis of Multi- threaded Programs with Dynamic Linked Structures.” Proceedings of Computer Aided Verification - 19th International Conference (CAV’07). Vol. 4590. Lecture Notes in Com- puter Science. Springer, 2007, pp. 207–220. [BGH09] Benedikt Bollig, Manuela-Lidia Grindei, Peter Habermehl. “Realizability of Concurrent Recursive Programs.” Proceedings of Foundations of Software Science and Computational Structures - 12th International Conference (FOSSACS’09). Vol. 5504. Lecture Notes in Computer Science. Springer, 2009, pp. 410–424. [BHHTV08] Ahmed Bouajjani, Peter Habermehl, Lukas´ Hol´ık, Tayssir Touili, Tomas´ Vojnar. “Antichain-Based Universality and Inclusion Testing over Nondeterministic Finite Tree Automata.” Proceedings of Implementation and Applications of Automata - 13th Interna- tional Conference (CIAA’08). Vol. 5148. Lecture Notes in Computer Science. Springer, 2008, pp. 57–67. [BHIKV09] Marius Bozga, Peter Habermehl, Radu Iosif, Filip Konecny,´ Tomas´ Vojnar. “Automatic Verification of Integer Array Programs.” Proceedings of Computer Aided Verification - 21st International Conference (CAV’09). Vol. 5643. Lecture Notes in Computer Science. Springer, 2009, pp. 157–172. [BHKL09] Benedikt Bollig, Peter Habermehl, Carsten Kern, Martin Leucker. “Angluin-Style Learn- ing of NFA.” Proceedings of the 21st International Joint Conference on Artificial Intelli- gence (IJCAI’09). 2009, pp. 1004–1009. [BJS07] Ahmed Bouajjani, Yan Jurski, Mihaela Sighireanu. “A Generic Framework for Reason- ing About Dynamic Networks of Infinite-State Processes.” Proceedings of Tools and Al- gorithms for the Construction and Analysis of Systems - 13th International Conference (TACAS’07). Vol. 4424. Lecture Notes in Computer Science. Springer, 2007, pp. 690–705. [BLLM09] Thomas Brihaye, Arnaud Da Costa Lopes, François Laroussinie, Nicolas Markey. “ATL with Strategy Contexts and Bounded Memory.” Proceedings of Logical Foundations of Computer Science, International Symposium (LFCS’09). Vol.5407. Lecture Notes in Com- puter Science. Springer, 2009, pp. 92–106. [BLMO07] Thomas Brihaye, François Laroussinie, Nicolas Markey, Ghassan Oreiby. “Timed Con- current Game Structures.” Proceedings of Concurrency Theory - 18th International Con- ference (CONCUR’07). Vol. 4703. Lecture Notes in Computer Science. Springer, 2007, pp. 445–459.

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[BMM11] Ahmed Bouajjani, Roland Meyer, Eike Mohlmann.¨ “Deciding Robustness against Total Store Ordering.” Proceedings of Automata, Languages and Programming - 38th Interna- tional Colloquium (ICALP’11). Vol. 6756. Lecture Notes in Computer Science. Springer, 2011, pp. 428–440. [Cac07] Thierry Cachat. “Tree Automata Make Ordinal Theory Easy.” Algorithmic-Logical The- ory of Inﬁnite Structures. Vol. 07441. Dagstuhl Seminar Proceedings. Internationales Begegnungs- und Forschungszentrum fuer Informatik (IBFI), Schloss Dagstuhl, Germany, 2007. [CCGP11] Francesco Carrabs, Raffaele Cerulli, Monica Gentili, Gennaro Parlato. “A Tabu Search Heuristic Based on k-Diamonds for the Weighted Feedback Vertex Set Problem.” Pro- ceedings of Network Optimization - 5th International Conference (INOC’11). Vol. 6701. Lecture Notes in Computer Science. Springer, 2011, pp. 589–602. [CDGFS11] Julien Clement,´ Carole Delporte-Gallet, Hugues Fauconnier, Mihaela Sighireanu. “Guidelines for the Veriﬁcation of Population Protocols.” Proceedings of the Interna- tional Conference on Distributed Computing Systems (ICDCS’11). IEEE Computer So- ciety, 2011, pp. 215–224. [CG10] Patrick Cegielski,´ Irene` Guessarian. “Normalization of Some Extended Abstract State Ma- chines.” Fields of Logic and Computation, Essays Dedicated to Yuri Gurevich on the Occa- sion of His 70th Birthday. Vol. 6300. Lecture Notes in Computer Science. Springer, 2010, pp. 165–180. [CH08a] Julien Cristau, Florian Horn. “Graph Games on Ordinals.” Proceedings of IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS’08). Vol. 2. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2008, pp. 143–154. [CH08b] Julien Cristau, Florian Horn. “On Reachability Games of Ordinal Length.” Proceedings of Theory and Practice of Computer Science - 34th Conference on Current Trends in Theory and Practice of Computer Science (SOFSEM’08). Vol. 4910. Lecture Notes in Computer Science. Springer, 2008, pp. 211–221. [CHH11] Krishnendu Chatterjee, Thomas A. Henzinger, Florian Horn. “The Complexity of Request- Response Games.” Proceedings of Language and Automata Theory and Applications - 5th International Conference (LATA’11). Vol. 6638. Lecture Notes in Computer Science. Springer, 2011, pp. 227–237. [CHL10] Krishnendu Chatterjee, Florian Horn, Christof Loding.¨ “Obliging Games.” Proceedings of Concurrency Theory - 21th International Conference (CONCUR’10). Vol. 6269. Lecture Notes in Computer Science. Springer, 2010, pp. 284–296. [CHMOS08] Arnaud Carayol, Matthew Hague, Antoine Meyer, C.-H. Luke Ong, Olivier Serre. “Win- ning Regions of Higher-Order Pushdown Games.” Proceedings of the Twenty-Third An- nual IEEE Symposium on Logic in Computer Science (LICS’08). IEEE Computer Society, 2008, pp. 193–204. [Dav08] Claire David. “Complexity of Data Tree Patterns over XML Documents”. Proceedings of Mathematical Foundations of Computer Science 2008, 33rd International Symposium (MFCS’08). Vol. 5162. Lecture Notes in Computer Science. Springer, 2008, pp. 278–289. [DDHL09] Ajoy Kumar Datta, Stephane´ Devismes, Florian Horn, Lawrence L. Larmore. “Self- Stabilizing k-out-of-l exclusion on tree networks.” Proceedings of the 23rd IEEE Interna- tional Symposium on Parallel and Distributed Processing (IPDPS’09). IEEE, 2009, pp. 1– 8.

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[DDS12] Stephane´ Demri, Amit Kumar Dhar, Arnaud Sangnier. “Taming Past LTL and Flat Counter Systems”. Proceedings of the 6th International Joint Conference on Automated Reasoning (IJCAR’12). Vol. 7634. Lecture Notes in Artificial Intelligence. Springer, 2012. [DGH10] Antoine Durand-Gasselin, Peter Habermehl. “On the Use of Non-deterministic Automata for Presburger Arithmetic.” Proceedings of Concurrency Theory - 21th International Con- ference (CONCUR’10). Vol. 6269. Lecture Notes in Computer Science. Springer, 2010, pp. 373–387. [DGH12] Antoine Durand-Gasselin, Peter Habermehl. “Ehrenfeucht-Fra¨ısse´ goes elementarily automatic for structures of bounded degree.” Proceedings of the 29th International Sympo- sium on Theoretical Aspects of Computer Science (STACS’12). Vol. 14. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2012, pp. 242–253. [DSZ11] Giorgio Delzanno, Arnaud Sangnier, Gianluigi Zavattaro. “On the Power of Cliques in the Parameterized Verification of Ad Hoc Networks.” Proceedings of Foundations of Software Science and Computational Structures - 14th International Conference (FOSSACS’11). Vol. 6604. Lecture Notes in Computer Science. Springer, 2011, pp. 441–455. [DSZ12] Giorgio Delzanno, Arnaud Sangnier, Gianluigi Zavattaro. “Verification of Ad Hoc Net- works with Node and Communication Failures”. FMOODS/FORTE. Vol. 7273. Lecture Notes in Computer Science. Springer, 2012, pp. 235–250. [EQR11] Michael Emmi, Shaz Qadeer, Zvonimir Rakamaric. “Delay-bounded scheduling.” Pro- ceedings of the 38th ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages (POPL’11). ACM, 2011, pp. 411–422. [FGO12] Nathanael¨ Fijalkow, Hugo Gimbert, Youssouf Oualhadj. “Deciding the Value 1 Prob- lem for Probabilistic Leaktight Automata”. Proceedings of the Twenty-Seventh Annual ACM/IEEE Symposium on Logic in Computer Science (LICS’12). ACM SIGACT, IEEE Computer Society, 2012. [GH08a] Hugo Gimbert, Florian Horn. “Simple Stochastic Games with Few Random Vertices Are Easy to Solve.” Proceedings of Foundations of Software Science and Computational Struc- tures - 11th International Conference (FOSSACS’08). Vol. 4962. Lecture Notes in Com- puter Science. Springer, 2008, pp. 5–19. [GH08b] Hugo Gimbert, Florian Horn. “Solving Simple Stochastic Games.” Proceedings of Logic and Theory of Algorithms - 4th Conference on Computability in Europe (CiE’08). Vol. 5028. Lecture Notes in Computer Science. Springer, 2008, pp. 206–209. [GH10] Hugo Gimbert, Florian Horn. “Solving Simple Stochastic Tail Games.” Proceedings of the Twenty-First Annual ACM-SIAM Symposium on Discrete Algorithms (SODA’10). SIAM, 2010, pp. 847–862. [GM07] Paul Gastin, Pierre Moro. “Minimal Counterexample Generation for SPIN.” Proceedings of Model Checking Software - 14th International SPIN Workshop (SPIN’07). Vol. 4595. Lecture Notes in Computer Science. Springer, 2007, pp. 24–38. [HHRSV11] Peter Habermehl, Lukas´ Hol´ık, Adam Rogalewicz, Jir´ı Simacek,´ Tomas´ Vojnar. “Forest Automata for Verification of Heap Manipulation.” Proceedings of Computer Aided Verifi- cation - 23rd International Conference (CAV’11). Vol. 6806. Lecture Notes in Computer Science. Springer, 2011, pp. 424–440. [HIRV07] Peter Habermehl, Radu Iosif, Adam Rogalewicz, Tomas´ Vojnar. “Proving Termination of Tree Manipulating Programs.” Proceedings of Automated Technology for Verification and Analysis - 5th International Symposium (ATVA’07). Vol. 4762. Lecture Notes in Computer Science. Springer, 2007, pp. 145–161.

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[HIV08a] Peter Habermehl, Radu Iosif, Tomas´ Vojnar. “A Logic of Singly Indexed Arrays.” Proceed- ings of Logic for Programming, Artificial Intelligence, and Reasoning - 15th International Conference (LPAR’08). Vol. 5330. Lecture Notes in Computer Science. Springer, 2008, pp. 558–573. [HIV08b] Peter Habermehl, Radu Iosif, Tomas´ Vojnar. “What Else Is Decidable about Integer Ar- rays?.” Proceedings of Foundations of Software Science and Computational Structures - 11th International Conference (FOSSACS’08). Vol. 4962. Lecture Notes in Computer Sci- ence. Springer, 2008, pp. 474–489. [HMO10] Jochen Hoenicke, Roland Meyer, Ernst-Rudiger¨ Olderog. “Kleene, Rabin, and Scott Are Available.” Proceedings of Concurrency Theory - 21th International Conference (CON- CUR’10). Vol. 6269. Lecture Notes in Computer Science. Springer, 2010, pp. 462–477. [HMW10] Peter Habermehl, Roland Meyer, Harro Wimmel. “The Downward-Closure of Petri Net Languages.” Proceedings of Automata, Languages and Programming - 37th International Colloquium (ICALP’10). Vol. 6199. Lecture Notes in Computer Science. Springer, 2010, pp. 466–477. [Hor07b] Florian Horn. “Faster Algorithms for Finitary Games.” Proceedings of Tools and Algo- rithms for the Construction and Analysis of Systems - 13th International Conference (TACAS’07). Vol. 4424. Lecture Notes in Computer Science. Springer, 2007, pp. 472– 484. [Hor08] Florian Horn. “Explicit Muller Games are PTIME.” Proceedings of IARCS Annual Con- ference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS’08). Vol. 2. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2008, pp. 235–243. [HTW08] Florian Horn, Wolfgang Thomas, Nico Wallmeier. “Optimal Strategy Synthesis in Request-Response Games.” Proceedings of Automated Technology for Verification and Analysis - 6th International Symposium (ATVA’08). Vol. 5311. Lecture Notes in Computer Science. Springer, 2008, pp. 361–373. [KLTR09] Nicholas Kidd, Peter Lammich, Tayssir Touili, Thomas W. Reps. “A Decision Proce- dure for Detecting Atomicity Violations for Communicating Processes with Locks.” Pro- ceedings of Model Checking Software - 16th International SPIN Workshop (SPIN’09). Vol. 5578. Lecture Notes in Computer Science. Springer, 2009, pp. 125–142. [KM09] Victor Khomenko, Roland Meyer. “Checking pi-Calculus Structural Congruence is Graph Isomorphism Complete.” Proceedings of the Ninth International Conference on Applica- tion of Concurrency to System Design (ACSD’09). IEEE Computer Society, 2009, pp. 70– 79. [LKRT07] Akash Lal, Nicholas Kidd, Thomas W. Reps, Tayssir Touili. “Abstract Error Projection.” Proceedings of Static Analysis - 14th International Symposium (SAS’07). Vol. 4634. Lec- ture Notes in Computer Science. Springer, 2007, pp. 200–217. [LLM10] Arnaud Da Costa Lopes, François Laroussinie, Nicolas Markey. “ATL with Strategy Con- texts: Expressiveness and Model Checking.” Proceedings of IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS’10). Vol. 8. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2010, pp. 120–132. [LLM12] Arnaud Da Costa Lopes, François Laroussinie, Nicolas Markey. “Quantified CTL: expressiveness and model checking.” Proceedings of Concurrency Theory - 23nd International Conference (CONCUR’12). Lecture Notes in Computer Science. Springer, 2012.

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[LMM08] Nutan Limaye, Meena Mahajan, Antoine Meyer. “On the Complexity of Membership and Counting in Height-Deterministic Pushdown Automata.” Proceedings of Computer Sci- ence - Theory and Applications, Third International Computer Science Symposium in Rus- sia (CSR’08). Vol. 5010. Lecture Notes in Computer Science. Springer, 2008, pp. 240– 251. [LMP10a] François Laroussinie, Antoine Meyer, Eudes Petonnet. “Counting CTL.” Proceedings of Foundations of Software Science and Computational Structures - 13th International Con- ference (FOSSACS’10). Vol. 6014. Lecture Notes in Computer Science. Springer, 2010, pp. 206–220. [LMP10b] François Laroussinie, Antoine Meyer, Eudes Petonnet. “Counting LTL.” Proceedings of the 17th International Symposium on Temporal Representation and Reasoning (TIME’10). IEEE Computer Society, 2010, pp. 51–58. [LS10]S ebastien´ Labbe,´ Arnaud Sangnier. “Formal Verification of Industrial Software with Dy- namic Memory Management.” Proceedings of the 16th IEEE Pacific Rim International Symposium on Dependable Computing (PRDC’10). IEEE Computer Society, 2010, pp. 77– 84. [LTKR08] Akash Lal, Tayssir Touili, Nicholas Kidd, Thomas W. Reps. “Interprocedural Analysis of Concurrent Programs Under a Context Bound.” Proceedings of Tools and Algorithms for the Construction and Analysis of Systems - 14th International Conference (TACAS’08). Vol. 4963. Lecture Notes in Computer Science. Springer, 2008, pp. 282–298. [Mey07] Antoine Meyer. “Traces of Term-Automatic Graphs.” Proceedings of Mathematical Foun- dations of Computer Science 2007, 32nd International Symposium (MFCS’07). Vol. 4708. Lecture Notes in Computer Science. Springer, 2007, pp. 489–500. [MG09] Roland Meyer, Roberto Gorrieri. “On the Relationship between π-Calculus and Finite Place/Transition Petri Nets.” Proceedings of Concurrency Theory - 20th International Conference (CONCUR’09). Vol. 5710. Lecture Notes in Computer Science. Springer, 2009, pp. 463–480. [MP11] P. Madhusudan, Gennaro Parlato. “The tree width of auxiliary storage.” Proceedings of the 38th ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages (POPL’11). ACM, 2011, pp. 283–294. [MPQ11] P. Madhusudan, Gennaro Parlato, Xiaokang Qiu. “Decidable logics combining heap structures and data.” Proceedings of the 38th ACM SIGPLAN-SIGACT Symposium on Princi- ples of Programming Languages (POPL’11). ACM, 2011, pp. 611–622. [MS10] Roland Meyer, Tim Strazny. “Petruchio: From Dynamic Networks to Nets.” Proceedings of Computer Aided Verification - 22nd International Conference (CAV’10). Vol. 6174. Lec- ture Notes in Computer Science. Springer, 2010, pp. 175–179. [PST07] Gael¨ Patin, Mihaela Sighireanu, Tayssir Touili. “Spade: Verification of Multithreaded Dy- namic and Recursive Programs.” Proceedings of Computer Aided Verification - 19th Inter- national Conference (CAV’07). Vol. 4590. Lecture Notes in Computer Science. Springer, 2007, pp. 254–257. [SS07] Mathias Samuelides, Luc Segoufin. “Complexity of Pebble Tree-Walking Automata.” Proceedings of Fundamentals of Computation Theory - 16th International Symposium (FCT’07). Vol. 4639. Lecture Notes in Computer Science. Springer, 2007, pp. 458–469. [ST11] Fu Song, Tayssir Touili. “Efficient CTL Model-Checking for Pushdown Systems.” Pro- ceedings of Concurrency Theory - 22nd International Conference (CONCUR’11). Vol. 6901. Lecture Notes in Computer Science. Springer, 2011, pp. 434–449.

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[ST12a] Fu Song, Tayssir Touili. “Efﬁcient Malware Detection using Model Checking.” 18th international symposium on Formal Methods (FM 2012). 2012. [ST12b] Fu Song, Tayssir Touili. “PuMoC: A CTL Model-Checker For Sequential Programs.” 27th IEEE/ACM International Conference On Automated Software Engineering (ASE 2012). 2012. [ST12c] Fu Song, Tayssir Touili. “Pushdown Model Checking for Malware Detection.” Proceed- ings of Tools and Algorithms for the Construction and Analysis of Systems - 18th Interna- tional Conference (TACAS’12). Vol. 7214. Lecture Notes in Computer Science. Springer, 2012, pp. 110–125. [Tou09] Tayssir Touili. “Constrained Reachability of Process Rewrite Systems.” Proceedings of Theoretical Aspects of Computing - 6th International Colloquium (ICTAC’09). Vol. 5684. Lecture Notes in Computer Science. Springer, 2009, pp. 307–321.

C-ACTWI : International workshop proceedings

[ADR08] Parosh Aziz Abdulla, Giorgio Delzanno, Ahmed Rezine. “Monotonic Abstraction in Pa- rameterized Verification.” Workshop on Reachability Problems in Computational Models, Electr. Notes Theor. Comput. Sci. 223 (2008), pp. 3–14. [BDJS09] Ahmed Bouajjani, Cezara Dragoi, Yan Jurski, Mihaela Sighireanu. “Rewriting Systems over Nested Data Words.” Proceedings of the Annual Doctoral Workshop on Mathematical and Engineering Methods in Computer Science (MEMICS’09). Vol. 13. OASICS. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, Germany, 2009. [BST07] Ahmed Bouajjani, Jan Strejcek, Tayssir Touili. “On Symbolic Verification of Weakly Ex- tended PAD.” EXPRESS Workshop, Electr. Notes Theor. Comput. Sci. 175.3 (2007), pp. 47–64. [RNRT09] Narjes Ben Rajeb, Brahim Nasraoui, Riadh Robbana, Tayssir Touili. “Verifying Multi- threaded Recursive Programs with Integer Variables.” Infinity 2008, Electr. Notes Theor. Comput. Sci. 239 (2009), pp. 143–154. [ST09] Mihaela Sighireanu, Tayssir Touili. “Bounded Communication Reachability Analysis of Process Rewrite Systems with Ordered Parallelism.” Infinity 2006, Electr. Notes Theor. Comput. Sci. 239 (2009), pp. 43–56.

C-COM : Talks at conferences without proceedings or upon-invitation-only meetings

Dagstuhl Seminar 08171 Beyond the Finite: New Challenges in Verification and Semistructured Data, April 2008. Ahmed Bouajjani (Tutorial on Parametrized Verification). Dagstuhl Seminar 09301 Typing, Analysis and Verification of Heap-Manipulating Programs, July 2009. Ahmed Bouajjani (A logic for reasoning about programs with composite data structures) and Peter Habermehl (Verifying programs with arrays). Dagstuhl Seminar 10252 Game Semantics and Program Verification, June 2010. Peter Habermehl (Regular Model Checking). Dagstuhl Seminar 11011 Multi-Core Memory Models and Concurrency Theory, January 2011. Ahmed Bouajjani and Mohamed Faouzi Atig (Context-bounded analysis of programs with dynamic thread creation). Mysore Park Workshop The Chemistry of Concurrent and Distributed Programming, Infosys campus, Mysore, India, February 2011. Ahmed Bouajjani (Verifying programs under the TSO memory model).

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CP meets CAV Constraint Programming meets Computer Aided Program Veriﬁcation, Turunc¸, Turkey, June 2012. Ahmed Bouajjani (Tutorial on Symbolic Model Checking), Constantin Enea (Ab- stract constraint domains for heap manipulating programs analysis), and Peter Habermehl (Parikh images of languages).

DO : Editing of journals and other works

[BC10] Ahmed Bouajjani, Wei-Ngan Chin, eds. Proceedings of Automated Technology for Verifi- cation and Analysis - 8th International Symposium, (ATVA’10). Springer, 2010. [BHZ12] Ahmed Bouajjani, David Harel, Lenore D. Zuck. “Editor’s foreword.” J. Comput. Syst. Sci. 78.3 (2012), p. 822. [BM09] Ahmed Bouajjani, Oded Maler, eds. Proceedings of Computer Aided Verification - 21st International Conference (CAV’09). Springer, 2009. [GL10] Paul Gastin, François Laroussinie, eds. Proceedings of Concurrency Theory - 21th Inter- national Conference (CONCUR’10). Springer, 2010. [HV09] Peter Habermehl, Tomas´ Vojnar. “Preface.” Joint Proceedings INFINITY 2006, 2007, 2008, Electr. Notes Theor. Comput. Sci. 239 (2009), pp. 1–3. [TCJ10] Tayssir Touili, Byron Cook, Paul Jackson, eds. Proceedings of Computer Aided Verifica- tion - 22nd International Conference (CAV’10). Springer, 2010. [Tou12a] Tayssir Touili, ed. CAV 2010 Special Issue. Vol. 40. 2. Formal Methods in System Design. Springer, 2012.

COS : Chapters in scientiﬁc works

[ABE12] Rajeev Alur, Ahmed Bouajjani, Javier Esparza. “Model Checking Procedural Programs”. Handbook of Model Checking (2012). Ed. by Edmund Clarke, Thomas Henzinger, and Helmut Veith. to appear. [CGV11] Patrick Cegielski,´ Irene` Guessarian, Jean-Marc Vincent. “Algorithmique”. Introduction a` la Science Informatique. 2011, pp. 139–186. [GKQT12] Aarti Gupta, Vineet Kahlon, Shaz Qadeer, Tayssir Touili. “Model Checking Concurrent Programs”. Handbook of Model Checking (2012). Ed. by Edmund Clarke, Thomas Hen- zinger, and Helmut Veith. to appear.

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264 Chapter 6

Appendix: Modeling and Veriﬁcation

6.1 Composition and team organization

Responsible : Ahmed Bouajjani

6.1.1 List of current members

6.1.1.1 Permanent staff (2012)

Table 6.1: List of permanent members

Eugene` Asarin Pr U P7 Ahmed Bouajjani Pr U P7 Aldric Degorre MdC U P7 Constantin Enea MdC U P7 Irene` Guessarian Pr Emeritus U P6 Peter Habermehl MdC HDR U P7 Florian Horn CR CNRS Yan Jurski MdC U P7 Franc¸ois Laroussinie Pr U P7 Arnaud Sangnier MdC U P7 Mihaela Sighireanu MdC U P7 Tayssir Touili CR HDR CNRS

6.1.1.2 PhD students and Post-doctoral researchers (2012)

PhD students:

• Nicolas Basset. AMN grant. Univ. Paris-Est Marne-la-Vallee.´ Director: Eugene` Asarin, co- directed with Dominique Perrin (LIGM). • Amit Dhar. Univ. Paris Diderot grant. Director: Arnaud Sangnier, co-directed with Stephane´ Demri (LSV). • Antoine Durant-Gasselin. AMN grant. Univ Paris Diderot. Directors: Ahmed Bouajjani and Peter Habermehl. • Jad Hamza. AMN grant. Univ. Paris Diderot. Directors: Ahmed Bouajjani and Constantin Enea. • Eudes Petonnet. AMN grant. Univ. Paris Diderot. Director: Franc¸ois Laroussinie.

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• Fu Song. ANR grant (BinCOA ANR project). Univ. Paris Diderot. Director: Tayssir Touili.

Post-doctoral researcher: Michael Emmi (10/2010-09/2013)

6.1.2 Former members

6.1.2.1 Permanent members (2007-2011)

• Thierry Cachat, MdC U P7 since Sept 2004. On leave since Sept 2008. • Antoine Meyer, MdC U P7. Sept 2006–Aug 2009. Moved to LIGM, Univ Paris-Est Marne-la- Vallee.´

6.1.2.2 PhD and Post-doc researchers (2007-2011)

PhD students: • Mohamed Faouzi Atig, Oct 2006 – June 2010. Dir: A. Bouajjani and T. Touili. Post-doc at University of Uppsala (Sweden), group of Parosh Abdulla. • Claire David, Oct 2005 – Mai 2009. Dir: Anca Muscholl. MdC Univ Paris-Est Marne-la-Vallee.´ • Cezara Dragoi, Nov 2007 – Nov 2011. Dir: A. Bouajjani and M. Sighireanu. Post-doc at IST Austria, group of Thomas Henzinger. • Florian Horn, Sept 2004 – Nov 2008. Dir: Anca Muscholl. CNRS researcher, LIAFA. • Pierre Moro, Oct 2003 – Feb 2008. Dir: A. Bouajjani and P. Habermehl. Research engineer, EADS Astrium. • Mathias Samuelides, Sept 2003 – Dec 2007. Dir: Anca Muscholl.

Post-docs: • Severine´ Fratani, Sept 2006 – August 2007 (MdC Univ. de Provence, LIF) • Constantin Enea, Jan 2008 – August 2009 (MdC Univ Paris Diderot, LIAFA) • Ahmed Rezine, May 2008 – August 2009 (Assistant Professor, Univ Linkoping,¨ Sweden) • Roland Meyer, March 2009 – June 2010 (Junior-Professor, Univ Kaiserslautern, Gernany) • Gennaro Parlato, April 2010 – May 2011 (Lecturer, Univ Southampton, UK)

6.1.2.3 Long stay visitors (2007-2011)

• Thomas Reps, Pr University of Wisconsin at Madison, Sept 2007 – Aug 2008 • Susan Horwitz, Pr University of Wisconsin at Madison, Sept 2007 – Aug 2008 • Nicholas Kidd, PhD student, U Wisconsin-Madison, Sept 2008 – Aug 2008 • Akash Lal, PhD student, U Wisconsin-Madison, Jan 2008 – Aug 2008 • Junghee Lim, PhD student, U Wisconsin-Madison, Sept 2008 – Aug 2008

6.1.2.4 Master students and Interns (2007-2011)

M2 MPRI master students • Nicolas Basset, 2009. Dir: Eugene Asarin. • Raphael¨ Chane-Yack-Fa, 2008. Dir. Eugene Asarin. • Amit Kumar Dhar, 2011. Dir: Arnaud Sangnier and Stephane´ Demri (LSV). • Antoine Durand-Gasselin, 2009. Dir: Peter Habermehl.

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• Nathanael¨ Fijalkow, 2010. Dir: Florian Horn. • Jad Hamza, 2011. Dir: Ahmed Bouajjani and Constantin Enea. • Vlad Saveluc, 2012. Dir: Constantin Enea and Mihaela Sighireanu.

Interns • Maria Abramiuc, 4 months, March-June, 2011 • Piotr Kordy, PhD student at the University of Twente (Netherlands), 4 months, Jan-April 2007 • Suneetha Nadella, 3 months, May-July 2010 • Eike Mohlmann,¨ Master thesis student at University of Oldenburg (Germany), 6 months, Oct 2009-Jan 2010 and May-June 2010. • Selma Sa¨ıdi, 4 months, April-July 2007 • Asma Sghaier, 6 months, Master intern., Ecole Polytechnique de Tunis, February-July 2009 • Riccardo Traverso, PhD student at the Univesity of Genoa, 2 months, May-June 2012 • Vlad Seveluc, 4 months, March-June, 2011

6.1.3 Visitors

• Parosh Abdulla (U Uppsala), several visits of 1 week. • Giorgio Delzanno (U Genoa), 2 months, 2011. • Javier Esparza (TU Munich), 1 week, 2010. • Martin Leucker (TU Munich), 1 month, 2007. • Vassily Lyubetsky (Moscou), 1 month 2009. • Shaz Qadeer (Microsoft Research, Redmond), 1 week, 2008. • Alexander Rabinovich (U Tel Aviv), 1 month, 2007. • Andrey Rybalchenko (TU Munich), 1 month, 2010. • Jeremy Sproston (U Torino), 1 month, 2012. • Serdar Tasiran (Koc¸Univ, Istanbul), 1 month, 2012. • Tomas Vojnar (TU Brno), several visits of 1 to 4 weeks. 6.1.4 Team organization

6.1.4.1 Funding and resource management

Sources of funding are: • ANR: Several national collaboration projects (8 in total, coordination of 4 of them). • 1 COST collaborative action. • 7 bilateral cooperation projects. • IUF: Financial support to F. Laroussinie. • Fond. Sci. Math.: 1 two-year Post-doc position (Michael Emmi), and 1 Research master grant (Vlad Saveluc). • Doct. Dept. ENS Cachan: several PhD grants, currently 3 (A. Durand-Gasselin, Jad Hamza, Eudes Petonnet) + 1 (Nicolas Basset at UMLV) • Doctoral School UP7: 1 PhD grant (Amit Kumar Dhar) The management of the resources is made by the responsible of each project, in agreement with the head of the team. In normal time, (almost) every member of the team is involved in a funded project. A solidarity principle is applied within the team which consists in using, as much as possible, available resources to cover the needs of those who are not involved in a funded project.

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6.1.4.2 Team activities

• The team is organized around three closely related research topics: (T1) Model checking, temporal logics and synthesis, (T2) Timed and hybrid systems, and (T3) Program verification. The activities in these axes are headed and organized respectively by F. Laroussinie, E. Asarin, and A. Bouajjani. Most of the work in the team is carried out collegially within small collaborative groups. • The MV team has a weekly seminar http://www.liafa.univ-paris-diderot.fr/web9/manifsem/listmanifannee en.php?typecongres=4. Talk announcements are broadly diffused in the area. The goal of this seminar is twofold: The first goal is to attract talks by external researchers on recent work or tutorials by experts on various topics of interest. For that, we have invited speakers on various topics such as • Program analysis/verification/design: Jean-Christpohe Filliatre,ˆ Klaus Havelund, Viktor Kuncak, Rupak Majumdar, George Necula, Andreas Podelski, Shaz Qadeer, Xavier Rival, Andrey Rybalchenko, Joseph Sifakis, Tom Reps, Viktor Vafeiadis, etc., • Automata/logic based verification, timed systems, infinite-state systems: Bernard Boigelot, Stephane´ Demri, Jean Goubault-Larrecq, Madavan Mukund, Markus Muller-Olm,¨ Joel Ouaknine, Alexander Rabinovitch, Jean-François Raskin, Jeremy Sproston, Mahech Viswanathan, Thomas Wahl, James Worrell, etc., • Concurrent and distributed systems/algorithms: Hagit Attiya, Rachid Guerraoui, Marc Shapiro, etc. The second goal is to allow locals to expose their work and get feedback from other researchers than their close collaborators, which contributes to the communication inside the team and its cohesion. The first slot of each month is reserved to a local speaker. • Students are encouraged to attend doctoral schools (e.g., MOVEP), and members of the team are encouraged to attend at least once every year a major conference in our area such as CAV, CONCUR, ETAPS, or POPL, even if they do not have a paper to present at that event. (For instance, all students have been sent to ETAPS’12.) • Students are also encouraged to visit other research groups. (For instance, Antoine Durand- Gasselin is visiting Rajeev Alur at U Penn for 4 months this year.) Students are closely supervised and encouraged to defend their theses within 3 to 4 years. Six PhD theses have been defended. • Assistant professors (MdC) and researchers (CR) are encouraged to develop a research project and to present a Habilitation. Two Habilitations have been defended (P. Habermehl and T. Touili) and one is in preparation (M. Sighireanu).

6.1.4.3 Services to the community and administrative responsibilities

• Deputy-director of the Doctoral School Mathematical Sciences of Paris (Ecole doctoral “Sci- ences Mathematiques´ de Paris Centre”) ED386, and responsible of the Computer Science section. Ahmed Bouajjani, since January 2010. • Deputy-director of the department of Computer Science (UFR d’Informatique) of the University Paris Diderot. Franc¸ois Laroussinie, 2008–2012. • Director of the department of Computer Science (UFR d’Informatique) of the University Paris Diderot. Franc¸ois Laroussinie, since March 2012. • Member of the Administration Council (Conseil d’Administration) of the University Paris Diderot, from Sept 2005 to March 2009, and co-responsible of the Funding Commission (Com- mission des Moyens) devoted to the negotiation and the supervision of the budgets of the 18 components of the university, in 2007-2009. Mihaela Sighireanu.

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• Responsible of the Computer Science program of the Engineering School of the University Paris Diderot (EIDD), Eugene` Asarin, since 2010. • Responsible of the L2 (2nd year) of the Bachelor of Computer Science (Licence d’Informatique) of the University of Paris Diderot. Franc¸ois Laroussinie, 2008–2012. • Responsible of the M2 (5th year, master level), of the specialization “Critical Software” of the Master of Computer Science of the University of Paris Diderot. Ahmed Bouajjani. 2004-2012. 6.2 Grants and research projects

6.2.1 Coordination of international projects

List of coordinated bilateral cooperation projects: CMCU – Tunisie Title: Advanced Techniques for Software Verification. Coordinators: Tayssir Touili and Riadh Robbana, Ecole Polytechnique de Tunis & Universite´ de Tunis, 2006-2009. REVERA – Moscou Title: Regulation of gene expression, evolution of regulation signals in bacteria: Modeling and analysis using automatic verification methods. “Convention d’echanges”´ CNRS – Russian Academy of Sciences. Coordinators: Eugene Asarin and Vassily Lyubetsky, Institute for Information Transmission Problems, Moscou, 2008-2009. PHC Barrande – Brno Title: Advanced Techniques for the Verification of Infinite-State Systems. Co- ordinators: Peter Habermehl and Tomas Vojnar, TU Brno (Czech Rep.), 2008-09. PHC Procope – Munster¨ Symbolic Analysis of Complex Features of Software. Coordinator: Tayssir Touili and Markus Muller-Olm,¨ University of Munster¨ (Germany), 2006-09. PHC Procope – Lubeck¨ Title: LeMon – Learning Monitors for refactoring legacy systems. Coordina- tors: Peter Habermehl and Martin Leucker, University of Lubeck¨ (Germany), 2012-13. PHC Jules Verne Title: Algorithms and Formal Methods for Distributed Computing. Coordinators: François Laroussinie and Luca Aceto, University of Reykjavik (Iceland), 2010-11.

6.2.2 Coordination of national projects

AVERILES (2006-2009). Type: RNTL (Reseau´ National en Technologies Logicielles). Title : Analy- sis of Embedded Systems with Dynamic Memory Structures. Partners : LIAFA, LSV, VERIMAG, EDF. Coordinator: Peter Habermehl. AVERISS (2007-2011). Type: ANR SETIN. Title : Automated Veriﬁcation of Software Systems. Part- ners : LIAFA, LaBRI, LSV. Coordinator: Ahmed Bouajjani. DOTS (2007-2011). Type: ANR SETIN. Title : Distributed Open Timed Systems. Partners : LIAFA, IRCCyN, IRISA, LaBRI, LAMSADE, LSV. Coordinator: Franc¸ois Laroussinie. EQINOCS (2012-2015). Type: ANR BLANC. Title: Entropy and quantity of information in models of computational systems. (Entropie et quantite´ d’information dans les modeles` des systemes` computationnels). Partners: LIAFA, LACL, LIGM, VERIMAG. Coordinator: Eugene` Asarin.

6.2.3 Participation in international projects

Collaboration projects: COST action IC0901. Title: Rich-Model Toolkit - An Infrastructure for Reliable Computer Systems, 2009-2012. Responsible at LIAFA: Tayssir Touili. Coordinator: Viktor Kuncak (EPFL, Switzer- land). PHC Barrande – Brno Automata and Logics for Symbolic Software Veriﬁcation. Participant: Peter Habermehl. Coordinators: Adam Rogalewicz (TU Brno, Czech Rep.) et Radu Iosif (VERIMAG, Grenoble).

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CNRS LIA/LEA (Laboratoire International/Europeen´ Associe)´ : INFINIS Franco-Argentinian intern. assoc. lab. Coordinators: Delia Kesner (Univ. Paris Diderot & CNRS, PPS) and Sergio Yovine (Univ. Buenos Aires & Conicet). Members from MV: Eugene Asarin and Ahmed Bouajjani. STRUCO Franco-Czech europ. assoc. lab. Coordinators: Jean-Sebastien´ Sereni (Univ. Paris Diderot & CNRS, LIAFA) & J. Nesetril (Charles University, Prague). Members from MV: Ahmed Boua- jjani and Peter Habermehl. INFORMEL Franco-Indian intern. assoc. lab. Coordinators: Paul Gastin (ENS Cachan & CNRS, LSV) & M. Mukund (Chennai Math. Inst.). Associated members from MV: Ahmed Bouajjani and Tayssir Touili.

6.2.4 Participation in national projects

AMAES (2006-2008). ANR ARA-SSIA. Title: Advanced Methods for Autonomous Embedded Sys- tems. Responsible at LIAFA: Mihaela Sighireanu. Coordinator: Saddek Bensalem (VERIMAG). BinCoA (2009-2012). ANR ARPEGE. Title: Binary Code Analysis. Responsible at LIAFA: Tayssir Touili. Coordinator: Sebastien´ Bardin (CEA). Veridyc (2010-2013). ANR SEGI. Title: Veriﬁcation of Dynamic C Programs. Responsible at LIAFA: Peter Habermehl. Coordinator: Radu Iosif (VERIMAG). ImpRo (2011-2014)). ANR BLANC. Title: Implementability and robustness of timed systems. Re- sponsible at LIAFA: Franc¸ois Laroussinie. Coordinator: Didier Lime (IRCCyN). 6.3 Research administration

6.3.1 Editorial activities

6.3.1.1 Editorial board member

Fundamenta Informaticae. Irene` Guessarian Formal Methods in System Design (FMSD). Ahmed Bouajjani ISRN Software Engeneering. Tayssir Touili Mathematical Structures in Computer Science (MSCS). Eugene` Asarin Techniques et Sciences Informatiques (TSI). Franc¸ois Laroussinie

6.3.1.2 Editor of special issues

Formal Methods in System Design (Springer). Special issue of the 21st Intern. Conf. on Computer Aided Veriﬁcation, 2009 (CAV’09). Volume 39, Number 3, December 2011. Ahmed Bouajjani, co-edited with Oded Maler (VERIMAG). Formal Methods in System Design (Springer). Special issue of the 22nd Intern. Conf. on Computer Aided Veriﬁcation, 2010 (CAV’10). Volume 40, Number 2, February 2012. Tayssir Touili. Journal of Computer and System Sciences (Elsevier). Special issue in commemoration of Amir Pnueli. Volume 78, Issue 3, May 2012. Ahmed Bouajjani, co-edited with David Harel (Weiz- mann Inst.) and Lenore Zuck (Univ. of Illinois).

6.3.2 Scientiﬁc management of conferences

6.3.2.1 Steering committee member

FORMATS. International Conference on Formal Modelling and Analysis of Timed Systems. Eugene` Asarin, since 2007.

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MOVEP. Ecole Jeunes Chercheurs Modelisation´ et Verification´ de Processus Paralleles` (School for young researchers on Modeling and Verification of Parallel Processes). François Laroussinie, 2002-2011. VECOS. International Workshop on Verification and Evaluation of Computer and Communication Sys- tems. Tayssir Touili, since 2012.

6.3.2.2 Program committee chair (Intenational conferences)

CAV 2009 21st International Conference on Computer Aided Verification, Grenoble, July 2009. Ahmed Bouajjani, co-chaired with Oded Maler (VERIMAG). ATVA 2010 8th International Symposium on Automated Technology for Verification and Analysis, Sin- gapore, September 2010. Ahmed Bouajjani, co-chaired with Wei-Ngan Chin (National Univ. of Singapore). CAV 2010 22nd International Conference on Computer Aided Verification, Edinburgh, UK, July 2010. Tayssir Touili, co-chaired with Byron Cook (Microsoft Research Cambridge) and Paul Jackson (Univ. Edinburgh). CONCUR 2010 21th International Conference on Concurrency Theory, Paris, September 2010. François Laroussinie, co-chaired with Paul Gastin (LSV).

6.3.2.3 Program committee chair (Intenational workshops)

INFINITY 2008 10th Intern. workshop on Verification of Infinite-State Systems, York, UK, August 2008. Peter Habermehl, co-chaired with Tomas Vojnar (TU Brno). VECOS 2011 5th Intern. workshop on Verification and Evaluation of Computer and Communication Systems, Tunis, September 2011. Tayssir Touili.

6.3.2.4 Workshops chair

FM 2012 18th International Symposium on Formal Methods, Paris, September 2012. Tayssir Touili, co-chaired with Nihal Pekergin (LACL) and Laure Petrucci (LIPN). VECOS 2011 5th Intern. workshop on Veriﬁcation and Evaluation of Computer and Communication Systems, Tunis, September 2011. Tayssir Touili, co-chaired with Nihal Pekergin (LACL).

6.3.2.5 Program committee member

International Conferences: ATVA 2010 Intern. Symp. on Automated Technology for Verification and Analysis. Ahmed Bouajjani (co-chair) ATVA 2011 Ahmed Bouajjani. CAV 2007 Intern. Conf. on Computer Aided Verification. Ahmed Bouajjani. CAV 2008 Ahmed Bouajjani. CAV 2009 Ahmed Bouajjani (co-chair) and Tayssir Touili. CAV 2010 Ahmed Bouajjani and Tayssir Touili (co-chair). CAV 2011 Tayssir Touili CIAA 2009 Intern.l Conf. on Implementation and Application of Automata. Ahmed Bouajjani. CONCUR 2009 Intern.l Conf. on Concurrency Theory. François Laroussinie. CONCUR 2010 François Laroussinie (co-chair).

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CONCUR 2011 Ahmed Bouajjani. CSR 2007 Intern. Computer Science Symposium in Russia. Eugene` Asarin. FM 2012 Intern. Symp. on Formal Methods. Ahmed Bouajjani. FORMATS 2007 Intern. Conf. on Formal Modelling and Analysis of Timed Systems. Eugene` Asarin. FORMATS 2008 Eugene` Asarin. FORMATS 2010 Eugene` Asarin. FOSSACS 2007 Intern. Conf. on Foundations of Software Science and Computation Structures. Ahmed Bouajjani FOSSACS 2011 François Laroussinie. FOSSACS 2012 Eugene` Asarin. FSTTCS 2009 IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science. Peter Habermehl. FSTTCS 2010 Ahmed Bouajjani. GandALF 2010 Intern. Symp. on Games, Automata, Logics, and Formal Verification. Ahmed Bouaj- jani. GandALF 2011 Tayssir Touili. HSCC 2010 ACM Intern. Conf. on Hybrid Systems: Computation and Control. Eugene` Asarin. HSCC 2011 Eugene` Asarin. ICALP 2012 Intern. Colloquium on Automata, Languages and Programming. François Laroussinie. LATA 2012 Intern. Conf. on Language and Automata Theory and Applications. Tayssir Touili. LICS 2012 Intern. ACM/IEEE Symposium on Logic in Computer Science. Ahmed Bouajjani. POPL 2010 ACM Intern. Symp. on Principles of Programming Languages. Tayssir Touili. POPL (ERC) 2011 External Review Committee. Ahmed Bouajjani POPL (ERC) 2013 External Review Committee. Michael Emmi RTA 2012 Intern. Conf. on Rewriting Techniques and Applications. Ahmed Bouajjani STACS 2007 Symposium on Theoretical Aspects of Computer Science. Eugene` Asarin. TACAS 2009 Intern. Conf. on Tools and Algorithms for the Construction and Analysis of Systems. Ahmed Bouajjani. TACAS 2010 Tayssir Touili. TACAS 2011 Ahmed Bouajjani and Peter Habermehl. TASE 2011 Intern. Symp. on Theoretical Aspects of Software Engineering. Ahmed Bouajjani. TCS 2012 IFIP Theoretical Computer Scicence. Ahmed Bouajjani. TIME 2011 Intern. Symp. on Temporal Representation and Reasoning. Peter Habermehl. VMCAI 2007-08 Intern. Conf. on Verification, Model Checking, and Abstract Interpretation. Tayssir Touili. VMCAI 2009 Ahmed Bouajjani. VMCAI 2011 Ahmed Bouajjani. VMCAI 2013 Michael Emmi. VSTTE 2010 Verified Software: Theories, Tools and Experiments. Ahmed Bouajjani.

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International Workshops: AVoCS 2012 Intern. Workshop on Automated Verification of Critical Systems. Tayssir Touili. EXPRESS 2009 International Workshop on Expressiveness in Concurrency. François Laroussinie. FICS 2012 International Workshop on Fixed Points in Computer Science. Irene` Guessarian. GT-VC 2007 Graph Transformation for Concurrency and Verification. Peter Habermehl. HAV 2007 Intern. Workshop on Heap Analysis and Verification. Ahmed Bouajjani. INFINITY 2008 Intern. Workshop on Verification of Infinite-State Systems. Peter Habermehl (co- chair). INFINITY 2009 Taysir Touili. INFINITY 2010 Peter Habermehl and Arnaud Sangnier INFINITY 2011 Peter Habermehl MEMICS 2008-12 Annual Doctoral Workshop on Mathematical and Engineering Methods in Com- puter Science. Peter Habermehl. MEMICS 2008 Taysir Touili. RP 2008 Intern. Workshop in Reachability Problems. Eugene` Asarin and Ahmed Bouajjani. RP 2009 Eugene` Asarin and Ahmed Bouajjani. RP 2010 Eugene` Asarin. RP 2011 Arnaud Sangnier. SPIN 2012 Intern. SPIN Workshop on Model Checking of Software. Tayssir Touili. VECOS 2008-12 4th Intern. workshop on Verification and Evaluation of Computer and Communica- tion Systems. Tayssir Touili.

6.3.3 Organization of scientiﬁc events

6.3.3.1 Scientiﬁc meetings

IFIP WG 2.2 Annual meeting of the IFIP working group 2.2 Ahmed Bouajjani. Paris, September 2011.

6.3.3.2 Member of organization committees

CONCUR 2010 21st Intern. Conf. on Concurrency Theory. Paris, Aug 31 – Sept 3, 2010. Florian Horn and Mihaela Sighireanu.

6.3.4 Participation in scientiﬁc juries and committees

6.3.4.1 International

• Member of the CAV Award committee. This is an annual award which recognizes a specific fundamental contribution or a series of outstanding contributions to the Computer-Aided Verification field. Ahmed Bouajjani, since 2012. • Member of the Future and Emerging Technologies (FET) Open evaluation jury, FP7-ICT program of the European Commission. 2007-2010. Ahmed Bouajjani. • External academic coordinator for the evaluation of the Computer Sciences and Informatics department of the ULB, Brussels, Belgium, 2011. Ahmed Bouajjani. • Member of the review panel of the german DFG Transregional Collaborative Research Centre (SFB/Transregio) 14 AVACS - Automatic Verification and Analysis of Complex Systems, 2011. Ahmed Bouajjani.

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• External member of a recruiting committee (for a Director) at Max Planck Society - MPI for Software Systems, Kaiserslautern, Germany, 2008. Ahmed Bouajjani. • Reviewer for recruiting/promotion committees: Univ. Saarlands, Saarbrucken,¨ Germany, 2011 and 2012 ; The IMDEA Software Institute, Madrid, Spain, 2012. Ahmed Bouajjani.

6.3.4.2 National

• Member of the AERES evaluation committee of the IRIT laboratory, Toulouse, 2009. Ahmed Bouajjani.

6.3.4.3 Commissions of specialists

• Eugene Asarin: Univ. de Provence Marseille (2009), Univ. Bordeaux (2011), Univ. Paris-Est Creteil´ (2012), Univ. Paris Diderot (2007, 2008, 2009, 2010) • Ahmed Bouajjani: France: Univ. de Provence Marseille (MdC, 2008), ENSEIRB-Bordeaux (PR, 2009), Univ. Paris Diderot (MdC, 2009, 2010), Univ. de Provence (MdC, 2010), ENSIMAG- Grenoble (MdC, 2010), Univ. Bordeaux (MdC, 2012), Univ. Grenoble (PR, 2012). • Constantin Enea: Univ. Paris 1 (MdC, 2012) • Peter Habermehl: Univ. Paris Diderot (MdC, 2009, 2010, 2011) • Franc¸ois Laroussinie: Univ. de Provence Marseille (2009 and 2010), Univ. Paris Diderot (2008, 2010, 2011, and 2012) • Mihaela Sighireanu: Univ. Paris Diderot (MdC, 2009, 2010 x 2) • Tayssir Touili: INRIA Rennes (CR, 2010)

6.4 International visibility

6.4.1 Invited talks

6.4.1.1 International conferences

FCT 2007. International Symposium on Fundamentals of Computation Theory. Budapest (Hungary), Aug 2007. Rewriting Systems with Data: A Framework for Reasoning about Systems with Un- bounded Structures over Infinite Data Domains. Ahmed Bouajjani. LATA 2012. International Conference on Language and Automata Theory and Applications. Coruna˜ (Spain), March 2012. Measuring Information in Timed Languages. Eugene` Asarin. VMCAI 2012. International Conference on Verification, Model Checking, and Abstract Interpreta- tion. Philadelphia (USA), Jan 2012. Abstract Domains for Automated Reasoning about List- Manipulating Programs with Infinite Data. Ahmed Bouajjani.

6.4.1.2 International workshops

AHA 2007 International symposium on Automatic Heap Analysis. Berlin (Germany), July 2007. Automata-based techniques for shape analysis. Ahmed Bouajjani. EXPRESS 2007 Intern. Workshop on Expressiveness in Concurrency. Lisboa (Portugal), Sept 2007. Alternating-time Temporal Logic: Expressivity, Complexity, Extensions. François Laroussinie. HAV 2007 Heap Analysis and Verification. Braga (Portugal), March 2007. Automata-Based Tech- niques for the Verification of Programs with Linked Data Structures. Ahmed Bouajjani. MEMICS 2009 Annual Doctoral Workshop on Mathematical and Engineering Methods in Computer Science. Znojmo (Czech Rep.), Nov 2009. Angluin-style learning of NFA. Peter Habermehl.

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WRLA 2008 International Workshop on Rewriting Logic and its Applications. Budapest (Hungary), March 2008. Rewriting systems with data: a framework for reasoning about unbounded networks of inﬁnite-state processes. Ahmed Bouajjani. RP 2009 International Workshop on Reachability Problems, LIX Colloquium. Palaiseau (France), 2009. On the Reachability Problem for Dynamic Networks of Concurrent Pushdown Systems. Ahmed Bouajjani. REORDER 2012 International Workshop on Memory Consistency Models. Berkeley (USA), July 2012. Checking state reachability for weak memory models. Ahmed Bouajjani.

6.4.2 Participation in upon-invitation-only scientiﬁc meetings

Dagstuhl Seminar 08171 Topic: Beyond the Finite: New Challenges in Verification and Semistruc- tured Data, April 2008. Tutorial on Parametrized Verification, Ahmed Bouajjani. Dagstuhl Seminar 09301 Topic: Typing, Analysis and Verification of Heap-Manipulating Programs, July 2009. Ahmed Bouajjani and Peter Habermehl. Dagstuhl Seminar 10252 Topic: Game Semantics and Program Verification, June 2010. Peter Haber- mehl. Dagstuhl Seminar 11011 Topic: Multi-Core Memory Models and Concurrency Theory, January 2011. Ahmed Bouajjani. Mysore Park Workshop The Chemistry of Concurrent and Distributed Programming, Infosys campus, Mysore, India, February 2011. Ahmed Bouajjani. CP meets CAV Constraint Programming meets Computer Aided Program Verification, Turunç, Turkey, June 2012. Ahmed Bouajjani (Tutorial on Symbolic Model Checking), Constantin Enea, and Peter Habermehl.

6.4.3 Invited stays

• University of Stuttgart, Germany. Host: Javier Esparza. 7 weeks. Feb–March 2007. Ahmed Bouajjani. • University of Uppsala, Sweden. Host: Parosh Abdulla. 5 weeks. May-June 2007. Ahmed Bouaj- jani. • Carnegie Mellon University, USA. Host: Edmund Clarke. 2 weeks, June 2007. Tayssir Touili. • University of Tel Aviv, Israel. Host: Mooly Sagiv. 2 weeks, July 2007. Ahmed Bouajjani. • University of Muenster, Germany. Host: Markus Mueller-Olm. 1 week in 2007 and 1 week in 2008. Tayssir Touili. • TU Munich, Germany. Host: Martin Leucker. 1 week, May 2008. Peter Habermehl. • Microsoft Research, Redmond, USA. Host: Shaz Qadeer. 4 weeks, August 2008. Ahmed Bouaj- jani. • Oxford University, UK. Host: Daniel Kroening. 1 week, June 2009. Tayssir Touili. • Microsoft Research, Redmond, USA. Host: Madanlal Musuvathi. 5 weeks, Aug–Sept 2010. Ahmed Bouajjani. • TU Brno, Czech Rep., Host: Tomas Vojnar. 1 week in 2007, 2 weeks in 2008, 1 week in 2009 and in 2010. Peter Habermehl. • University of Reykjavik, Island. Host: Luca Aceto, spring 2009. Franc¸ois Laroussinie. • Microsoft Research India, Bangalore. Host: Akash Lal. 3 weeks, Aug 2011. Ahmed Bouajjani.

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• National Taiwan University, Taipei. Host: Farn Wang. 2 weeks, Oct 2011. Ahmed Bouajjani. • Institute for Mathematical Science, National University of Singapore, Automata Theory and Ap- plications program. Host: P.S. Thiagarajan. 1 week, Sept 2011. Eugene` Asarin. • Microsoft Research India, Bangalore. Host: Akash Lal. 4 weeks, December 2011. Michael Emmi. • Chennai Mathematical Institute, India. Host: Narajan Kumar and Madhavan Mukund. 1 week, February 2012. Ahmed Bouajjani. • University of Uppsala, Sweden. Host: Parosh Abdulla. 2 weeks, April 2012. Arnaud Sangnier.

6.5 Educational, advising, and evaluation activities

6.5.1 List of defended PhD theses and Habilitations

6.5.1.1 Habilitations

1. Peter Habermehl, Veriﬁcation of systems with complex data structures using automata. Decem- ber 2009. 2. Tayssir Touili, Modeling and reachability analysis of concurrent recursive programs. December 2009.

6.5.1.2 Doctoral theses

Theses (listed in chronological order of defence) carried out and defended in the team, or directed by a member of the team 1. Mathias Samuelides, Pebble tree automata. Director: Anca Muscholl 1 and Luc Segoufin´ (LSV), December 2007. 2. Pierre Moro, Combining automata-based symbolic analysis and counter-example guided abstraction. Directors: Ahmed Bouajjani and Peter Habermehl. Univ. Paris Diderot, February 2008. 3. Florian Horn, Random Games. Directors: Anca Muscholl and Wolfgang Thomas (Aachen). Uni. Paris Diderot and Univ. of Aachen, October 2008. 4. Ghassan Oreiby, Logique Temporelle pour le controleˆ temporise´, Director: François Laroussinie, co-directed with Nicolas Markey (LSV), ENS Cachan, December 2008. 5. Claire David, Analysis of XML with unbounded data, Directors: Anca Muscholl and Luc Segoufin´ (LSV), May 2009. 6. Mohamed Faouzi Atig, Verification of Concurrent Programs: Decidability and Complexity. Di- rectors: Ahmed Bouajjani and Tayssir Touili. Univ. Paris Diderot, June 2010. 7. Arnaud da Costa, Propriet´ es´ de jeux multi-agents. Director: François Laroussinie, co-directed with Nicolas Markey (LSV), ENS Cachan, September 2011. 8. Cezara Dragoi, Automated Verification of Heap-Manipulating Programs with Infinite Data. Di- rectors: Ahmed Bouajjani and Mihaela Sighireanu. Univ. Paris Diderot, December 2011.

1. Anca Muscholl was member of the MV team until August 2006. Her three students, C. David, F. Horn, and M. Samuelides stayed members of our team until the end of their theses.

276 CHAPTER 6. APPENDIX: MODELING AND VERIFICATION

6.5.2 Reports on PhD and Habilitation theses

6.5.2.1 Reports on Habilitations

1. Stephane´ Demri, Logics for Specifying and Verifying (Logiques pour la Specification´ et Verification).´ ENS Cachan, June 2007. Reviewer: Ahmed Bouajjani. 2. Catalin Dima, Automata and Logics for the Verification of Timed and Multi-agents Systems. Univ. Paris-Est Creteil,´ Dec 2010. Reviewer: François Laroussinie. 3. Franck Cassez, Control of Timed Systems. Univ. of Nantes, Sept 2007. Reviewer: Ahmed Bouajjani. 4. Thomas Genet, Reachability Analysis of Rewriting for Software Verification. Univ. Rennes 1, Nov 2009. Reviewer: Ahmed Bouajjani. 5. Nicolas Markey, Verification of Embedded Systems: Algorithms and Complexity (Verification´ des systemes` embarques:´ Algorithmes et complexite).´ ENS Cachan, April 2011. Reviewer: Eugene` Asarin.

6.5.2.2 Reports on PhD theses

1. Pierre-Alain Reynier.Verification´ de systemes` temporises´ et distribues:´ modeles,` algorithmes et implementabilit´ e.´ ENS Cachan, June 2007. Reviewer: Ahmed Bouajjani. 2. Fernando Schapachnik. Timed Automata Model Checking in Monoprocessor and Multi- processor Architectures. Univ. of Buenos Aires (Argentina), October 2007. Reviewer: Ahmed Bouajjani. 3. Adam Rogalewicz. Verification of Programs with Complex Data Structures. TU Brno (Czech Rep.), Nov 2007. Reviewer: Tayssir Touili. 4. Regis´ Gascon. Specification´ et Verification´ de Propriet´ es´ Quantitatives sur des Automates a` Con- traintes. ENS Cachan, Nov 2007. Reviewer: Ahmed Bouajjani. 5. Mayank Saksena. Verifying Absence of Infinite Loops in Parameterized Protocols. Univ. of Uppsala (Sweden), April 2008. Opponent: Ahmed Bouajjani. 6. Laurent Bienvenu. Caracterisations´ de l’aleatoire´ par les jeux: impredictibilit´ e´ et stochasticite.´ Univ. de Provence, April 2008. Reviewer: Eugene` Asarin. 7. Cristobal´ Rojas Gonzales´ . Aleatoire´ et theorie´ ergodique : un point de vue algorithmique. Ecole Polytechnique and Univ. of Pisa, June 2008. Rewiever: Eugene` Asarin. 8. Dejvuth Suwimonteerabuth (Remy). Reachability in pushdown systems: Algorithms and applications. TU Munich (Germany), May 2009. Reviewer: Ahmed Bouajjani. 9. Louis-Marie Traonouez.Verification´ et depliages´ de reseaux´ de Petri temporels parametr´ es.´ Univ. of Nantes, Nov 2009. Reviewer: François Laroussinie. 10. Omer Landry Nguena Timo. Synthese` pour une logique temps-reel´ faible. Univ. de Bordeaux 1, Dec 2009. Rewiever: François Laroussinie. 11. Roman Manevich. Partially Disjunctive Shape Analysis. Univ. of Tel Aviv (Israel), 2009. Re- viewer: Ahmed Bouajjani. 12. Gerard´ Charly Basler. Model checking Boolean Programs. ETH Zurich, March 2010. Re- viewer: Tayssir Touili. 13. Thanh-Hung Nguyen. Constructive Verification of Component-based Systems. Institut National Polytechnique de Grenoble, VERIMAG, June 2010. Reviewer: Ahmed Bouajjani.

277 CHAPTER 6. APPENDIX: MODELING AND VERIFICATION

14. Alexander Heussner. Towards the verfication of safety properties for infinite communicating systems: decidability and abstraction refinement. Univ. of Bordeaux, June 2011. Reviewer: Tayssir Touili. 15. Pierre Chambart. On Post’s Embedding Problem and the Complexity of Lossy Channels. ENS Cachan, Sept 2011. Reviewer: Ahmed Bouajjani. 16. Julien Legriel. Optimisation multi-criteres` et ses applications aux systemes` embarques´ multi- processeurs. Univ. of Grenoble, Oct 2011. Reviewer: Eugene` Asarin. 17. Rajarshi Ray. Reachability Analysis of Hybrid Systems using Support Functions. Univ. of Grenoble, May 2012. Reviewer: Eugene` Asarin. 18. Tesnim Abdellatif. Rigorous Implementation of Real-time Systems. Univ. of Grenoble, June 2012. Rewiever: Eugene` Asarin. 19. Filip Konecny. Relational Verification of Programs with Integer Data. TU Brno (Czech Rep.) and Univ. of Grenoble, October 2012. Reviewer: Ahmed Bouajjani.

6.5.3 Educational activities

6.5.3.1 Courses in Research Masters

MPRI 2.8. Foundations of real time systems verification. Participants: François Laroussinie and Eugene` Asarin. MPRI 2.9. Verification of parametrized and dynamic systems. Participants: Ahmed Bouajjani, Peter Habermehl, Arnaud Sangnier, Mihaela Sighireanu, and Tayssir Touili.

6.5.3.2 Advanced courses, Doctoral and Research Schools

ECI 2012 Escueal de Ciencias Informaticas´ (School on Computer Science), University of Buenos Aires, Argentina, July 2012. Verification of Concurrent Programs. Ahmed Bouajjani. ECNU Summer School’10 Software Engineering Institute, East China National University Summer School, Shanghai, China, July 2010. Cyber-Physical Systems. Eugene` Asarin. EJC InfoMath 2007 Ecole Jeunes Chercheurs Informatique Mathematique´ (School for young researchers on Mathematical Computer Science), LORIA Nancy, March 2007. Eugene` Asarin. ETR 2009 Ecole d’et´ e´ Temps-Reel´ (Summer School on Real-Time), Paris, 2009. Games and Temporal Logics for the Verification of Timed Systems. François Laroussinie. FSFLA 2012 International Fall School on Formal Languages and Applications, Tarragona, Spain, Oc- tober 2012. Automated Verification of Concurrent Boolean Programs. Ahmed Bouajjani. MOVEP 2012. Ecole Jeunes Chercheurs Modelisation´ et Verification´ de Processus Paralleles` (School for young researchers on Modeling and Verification of Parallel Processes), Marseille, December 2012. Verification of Concurrent Programs, Ahmed Bouajjani. VTSA 2012 Summer School on Verification Technology, Systems and Applications. MPI Saarbrucken,¨ September 2012. Verification of Concurrent Programs under Weak Memory Models, Ahmed Bouajjani.

6.5.3.3 Popularization

Feteˆ de la Science Presentations and interactive workshops/demonstrations.

278 Septieme` partie

Bref historique du LIAFA

279

Bref historique du LIAFA

La creation´ du LIAFA remonte a` 1996, sur l’initiative de chercheurs et enseignants-chercheurs du LITP (Laboratoire d’Informatique Theorique´ et de Programmation). Jean-Eric Pin est nomme´ directeur du LIAFA en juin 1996, sous la forme d’une Equipe en Restructuration (ERS 586). Deux ans plus tard, le LIAFA est reconnu comme une Unite´ Mixte de Recherche (UMR 7089) par le CNRS et l’universite´ Paris Diderot, sous la direction de Daniel Krob. A cette date, le laboratoire est constitue,´ outre les personnels ITA et IATOS, doctorants, post-doctorants et visiteurs non-permanents, de 15 enseignants-chercheurs et 4 chercheurs CNRS. Il est structure´ en trois equipes´ : Algorithmique et combinatoire, Automates, et Modelisation´ et veriﬁcation,´ plus un axe transversal : Systemes` a` ev´ enements` discrets.

FIGURE 6.1 – Les locaux de Jussieu (gauche) et de Chevaleret (droite)

En 1999, le LIAFA dem´ enage´ de ses locaux du campus de Jussieu dans les locaux du batimentˆ de la rue du Chevaleret, dans le cadre du desamiantage´ de Jussieu. L’occupation des locaux de Chevaleret, initialement prevue´ pour une courte periode´ transitoire, va durer... plus de 13 ans. De fait, le laboratoire occupe toujours actuellement ces locaux dans l’attente de bureaux dans le batimentˆ Sophie Germain du campus de Paris Diderot (dem´ enagement´ prevu´ ﬁn 2012 - debut´ 2013).

FIGURE 6.2 – Les futurs locaux du campus de l’universite´ Paris Diderot

Daniel Krob assure la direction du LIAFA de 1998 a` 2002. En 2003, Jean-Eric Pin est nomme´ dere- chef directeur du LIAFA, pour le quadriennal 2003-2007. Michel Habib prend ensuite la direction du laboratoire a` partir de 2008 jusqu’a` sa nomination a` la direction du nouvel institut INS2I du CNRS (Institut des sciences de l’information et de leurs interactions) courant 2009. La direction du laboratoire est assuree´ par Pierre Fraigniaud depuis janvier 2010. Au 1er septembre 2012, le laboratoire inclut pres` de 110 membres, dont 34 enseignants-chercheurs, 24 chercheurs CNRS et 2 chercheurs INRIA. Il est structure´ en cinq equipes´ : Algorithmes et complexite,´ Algorithmique distribuee´ et graphes, Automates et applications, Combinatoire, et Modelisation´ et veriﬁcation.´

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