Prepared for submission to JCAP Exploring Cosmic Origins with CORE: Inflation Fabio Finelli,1;2 Martin Bucher,3;4 Ana Achúcarro,5;6 Mario Ballardini,7;1;2 Nicola Bartolo,8;9;10 Daniel Baumann,11;12 Sébastien Clesse,13 Josquin Errard,14 Will Handley,15;16 Mark Hindmarsh,17;18;19 Kimmo Kiiveri,18;19 Martin Kunz,20 Anthony Lasenby,15;16 Michele Liguori,8;9;10 Daniela Paoletti,1;2 Christophe Ringeval,21 Jussi Väliviita,18;19 Bartjan van Tent,22 Vincent Vennin,23 Peter Ade,24 Rupert Allison,11 Frederico Arroja,25 Marc Ashdown,16 A. J. Banday,26;27 Ranajoy Banerji,3 James G. Bartlett,3 Soumen Basak,28;29 Jochem Baselmans,30;31 Paolo de Bernardis,32 Marco Bersanelli,33 Anna Bonaldi,34 Julian Borril,35 François R. Bouchet,36 François Boulanger,37 Thejs Brinckmann,13 Carlo Burigana,1;2;38 Alessandro Buzzelli,32;39 Zhen-Yi Cai,40 Martino Calvo,41 Carla Sofia Carvalho,42 Gabriella Castellano,43 Anthony Challinor,11;16;44 Jens Chluba,34 Ivan Colantoni,43 Martin Crook,45 Giuseppe D’Alessandro,32 Guido D’Amico,46 Jacques Delabrouille,3 Vincent Desjacques,47;20 Gianfranco De Zotti,10 Jose Maria Diego,48 Eleonora Di Valentino,49;36 Stephen Feeney,50 James R. Fergusson,11 Raul Fernandez-Cobos,48 Simone Ferraro,51 Francesco Forastieri,38;52 Silvia Galli,36 Juan García-Bellido,53 Giancarlo de Gasperis,54;39 Ricardo T. Génova-Santos,55;56 Martina Gerbino,57 Joaquin González-Nuevo,58 Sebastian Grandis,59;60 Josh Greenslade,49 Steffen Hagstotz,59;60 Shaul Hanany,61 Dhiraj K. Hazra,3 Carlos Hernández-Monteagudo,62 Carlos Hervias-Caimapo,34 Matthew Hills,45 Eric Hivon,36 Bin Hu,63;64 Ted arXiv:1612.08270v2 [astro-ph.CO] 5 Apr 2017 Kisner,35 Thomas Kitching,65 Ely D. Kovetz,66 Hannu Kurki-Suonio,18;19 Luca Lamagna,32 Massimiliano Lattanzi,38;52 Julien Lesgourgues,13 Antony Lewis,67 Valtteri Lindholm,18;19 Joanes Lizarraga,6 Marcos López-Caniego,68 Gemma Luzzi,32 Bruno Maffei,37 Nazzareno Mandolesi,38;1 Enrique Martínez-González,48 Carlos J.A.P. Martins,69 Silvia Masi,32 Darragh McCarthy,70 Sabino Matarrese,8;9;10;71 Alessandro Melchiorri,32 Jean-Baptiste Melin,72 Diego Molinari38;52 Alessandro Monfardini,73 Paolo Natoli,38;52 Mattia Negrello,74 Alessio Notari,64 Filippo Oppizzi,8 Alessandro Paiella,32 Enrico Pajer,75 Guillaume Patanchon,3 Subodh P. Patil,76 Michael Piat,3 Giampaolo Pisano,74 Linda Polastri,38;52 Gianluca Polenta,77;78 Agnieszka Pollo,79;80 Vivian Poulin,13;81 Miguel Quartin,82 Andrea Ravenni,8 Mathieu Remazeilles,34 Alessandro Renzi,29;83 Diederik Roest,84 Matthieu Roman,14 Jose Alberto Rubiño-Martin,55;56 Laura Salvati,31 Alexei A. Starobinsky,85 Andrea Tartari,3 Gianmassimo Tasinato,86 Maurizio Tomasi33;87 Jesús Torrado,17 Neil Trappe,70 Tiziana Trombetti,1;2;38 Carole Tucker,75 Marco Tucci,20 Jon Urrestilla,6 Rien van de Weygaert,88 Patricio Vielva,48 Nicola Vittorio,54;39 Karl Young,61 for the CORE collaboration 1INAF/IASF Bologna, via Gobetti 101, I-40129 Bologna, Italy 2INFN, Sezione di Bologna, via Irnerio 46, I-40127 Bologna, Italy 3APC, Astroparticule et Cosmologie, Université Paris Diderot, CNRS/IN2P3, CEA/lrfu, Obser- vatoire de Paris Sorbonne Paris Cité, 10, rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13, France 4Astrophysics and Cosmology Research Unit, School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Durban 4041, South Africa 5Instituut-Lorentz for Theoretical Physics, Universiteit Leiden, 2333 CA, Leiden, The Nether- lands 6Department of Theoretical Physics, University of the Basque Country UPV/EHU, 48040 Bilbao, Spain 7Dipartimento di Fisica e Astronomia, Università di Bologna, Viale Berti Pichat, 6/2, I-40127 Bologna, Italy 8Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università degli Studi di Padova, Via Marzolo 8, I-35131, Padova, Italy 9INFN, Sezione di Padova, Via Marzolo 8, I-35131 Padova, Italy 10INAF, Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, I-35122 Padova, Italy 11DAMTP, Centre for Mathematical Sciences, University of Cambrige, Wilberforce Road, Cam- bridge, CB3 0WA, UK 12Institute of Physics, University of Amsterdam, Science Park, Amsterdam, 1090 GL, The Nether- lands 13Institute for Theoretical Particle Physics and Cosmology (TTK), RWTH Aachen University, D-52056 Aachen, Germany 14Institut Lagrange, LPNHE, place Jussieu 4, 75005 Paris, France. 15Astrophysics Group, Cavendish Laboratory, Cambridge, CB3 0HE, UK 16Kavli Institute for Cosmology, Cambridge, CB3 0HA, UK 17Department of Physics and Astronomy, University of Sussex, Falmer, Brighton, BN1 9QH, UK 18Department of Physics, Gustaf Hallstromin katu 2a, University of Helsinki, Helsinki, Finland 19Helsinki Institute of Physics, Gustaf Hallstromin katu 2, University of Helsinki, Helsinki, Finland 20Département de Physique Théorique and Center for Astroparticle Physics, Université de Genève, 24 quai Ansermet, CH–1211 Genève 4, Switzerland 21Centre for Cosmology, Particle Physics and Phenomenology, Institute of Mathematics and Physics, Louvain University, 2 chemin du Cyclotron, 1348 Louvain-la-Neuve, Belgium 22Laboratoire de Physique Théorique (UMR 8627), CNRS, Université Paris-Sud, Université Paris Saclay, Bâtiment 210, 91405 Orsay Cedex, France 23Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth PO1 3FX, United Kingdom 24School of Physics and Astronomy, Cardiff University, The Parade, Cardiff CF24 3AA, UK 25Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617 Taipei, Taiwan (R.O.C.) 26Université de Toulouse, UPS-OMP, IRAP, F-31028 Toulouse Cedex 4, France 27CNRS, IRAP, 9 Av. colonel Roche, BP 44346, F-31028 Toulouse Cedex 4, France 28Department of Physics, Amrita School of Arts and Sciences, Amritapuri, Amrita Vishwa Vidyapeetham, Amrita University, Kerala 690525, India 29SISSA, Astrophysics Sector, via Bonomea 265, 34136, Trieste, Italy 30SRON (Netherlands Institute for Space Research), Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands 31Terahertz Sensing Group, Delft University of Technology, Mekelweg 1, 2628 CD Delft, The Netherlands 32Physics Department "G. Marconi", University of Rome Sapienza and INFN, piazzale Aldo Moro 2, 00185, Rome, Italy 33Dipartimento di Fisica, Università degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy 34Jodrell Bank Centre for Astrophysics, Alan Turing Building, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester, M13 9PL, U.K. 35Computational Cosmology Center, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA 36Institut d’Astrophysique de Paris, UMR7095, CNRS & UPMC Sorbonne Universités, F-75014, Paris, France 37IAS (Institut d’Astrophysique Spatiale), Université Paris Sud, Bâtiment 121 91405 Orsay, France 38Dipartimento di Fisica e Scienze della Terra, Università di Ferrara, via Saragat 1, 44122 Ferrara, Italy 39INFN Roma 2, via della Ricerca Scientifica 1, I-00133, Roma, Italy 40CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, Uni- versity of Science and Technology of China, Hefei, Anhui 230026, China 41Univ. Grenoble Alpes, CEA INAC-SBT, 38000 Grenoble, France 42Institute of Astrophysics and Space Sciences, University of Lisbon, Tapada da Ajuda, 1349-018 Lisbon, Portugal 43Istituto di Fotonica e Nanotecnologie, CNR, Via Cineto Romano 42, 00156, Roma, Italy 44Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, UK 45STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, UK 46Theoretical Physics Department, CERN, Geneva, Switzerland 47Physics Department, Technion, Haifa 3200003, Israel 48IFCA, Instituto de Física de Cantabria (UC-CSIC), Avenida de Los Castros s/n, 39005 San- tander, Spain 49Sorbonne Universités, Institut Lagrange de Paris (ILP), F-75014, Paris, France 50Astrophysics Group, Imperial College London, Blackett Laboratory, Prince Consort Road, Lon- don, SW7 2AZ, UK 51Miller Institute for Basic Research in Science, University of California, Berkeley, CA 94720, USA 52INFN, Sezione di Ferrara, Via Saragat 1, 44122 Ferrara, Italy 53Instituto de Física Teórica UAM/CSIC, Universidad Autonoma de Madrid, 28049 Madrid, Spain 54Dipartimento di Fisica, Università di Roma “Tor Vergata”, Via della Ricerca Scientifica 1, I- 00133, Roma, Italy 55Instituto de Astrofísica de Canarias, Calle Vía Láctea s/n, La Laguna, Tenerife, Spain 56Departamento de Astrofísica, Universidad de La Laguna (ULL), La Laguna, Tenerife, 38206 Spain 57The Oskar Klein Centre for Cosmoparticle Physics, Department of Physics, Stockholm Univer- sity, AlbaNova, SE-106 91 Stockholm, Sweden 58Departamento de Física, Universidad de Oviedo, Calle Calvo Sotelo s/n, 33007 Oviedo, Spain 59Faculty of Physics, Ludwig-Maximilians Universität, 81679 Munich, Germany 60Excellence Cluster Universe, Boltzmannstrasse 2, D-85748 Garching, Germany 61School of Physics and Astronomy, University of Minnesota, 116 Church Street SE, Minneapolis, Minnesota 55455, United States 62Centro de Estudios de Física del Cosmos de Aragón (CEFCA), Plaza San Juan, 1, planta 2, E-44001, Teruel, Spain 63Department of Astronomy, Beijing Normal University, Beijing 100875, China 64Departament de Física Quàntica i Astrofísica i Institut de Ciències del Cosmos (ICCUB), Uni- versitat de Barcelona, Martí i Franquès 1, E-08028 Barcelona, Spain 65Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Darking, Surrey, RH5 6NT, UK 66Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles St., Balti- more, MD 21218, USA 67Department