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On Abelian Subgroups of Finitely Generated Metabelian
J. Group Theory 16 (2013), 695–705 DOI 10.1515/jgt-2013-0011 © de Gruyter 2013 On abelian subgroups of finitely generated metabelian groups Vahagn H. Mikaelian and Alexander Y. Olshanskii Communicated by John S. Wilson To Professor Gilbert Baumslag to his 80th birthday Abstract. In this note we introduce the class of H-groups (or Hall groups) related to the class of B-groups defined by P. Hall in the 1950s. Establishing some basic properties of Hall groups we use them to obtain results concerning embeddings of abelian groups. In particular, we give an explicit classification of all abelian groups that can occur as subgroups in finitely generated metabelian groups. Hall groups allow us to give a negative answer to G. Baumslag’s conjecture of 1990 on the cardinality of the set of isomorphism classes for abelian subgroups in finitely generated metabelian groups. 1 Introduction The subject of our note goes back to the paper of P. Hall [7], which established the properties of abelian normal subgroups in finitely generated metabelian and abelian-by-polycyclic groups. Let B be the class of all abelian groups B, where B is an abelian normal subgroup of some finitely generated group G with polycyclic quotient G=B. It is proved in [7, Lemmas 8 and 5.2] that B H, where the class H of countable abelian groups can be defined as follows (in the present paper, we will call the groups from H Hall groups). By definition, H H if 2 (1) H is a (finite or) countable abelian group, (2) H T K; where T is a bounded torsion group (i.e., the orders of all ele- D ˚ ments in T are bounded), K is torsion-free, (3) K has a free abelian subgroup F such that K=F is a torsion group with trivial p-subgroups for all primes except for the members of a finite set .K/. -
An Interview with Winifred (Tim) Asprey Conducted Friday, 23 March 2007 at Poughkeepsie, New York Interview Conducted by Viera Proulx
Computing Educators Oral History Project (CEOHP) Computing Educators Oral History Project An Interview with Winifred (Tim) Asprey Conducted Friday, 23 March 2007 At Poughkeepsie, New York Interview Conducted by Viera Proulx Copyright Statement This manuscript is being made available for research purposes only. All literary rights in the manuscript, including the right to publish, are reserved to the Computing Educators Oral History Project. No part of the manuscript may be quoted for publication, except by the interviewee, without the written permission of the Director of the Computing Educators Oral History Project. Request for permission to quote for publication should be addressed to Barbara Boucher Owens, either by email at [email protected] or via postal mail at Computing Educators Oral History Project, Southwestern University, P.O. Box 770, Gerogetown, TX 78627-0770 USA. The request should identify the specific passages to be quoted, describe the anticipated use of the passages, and identify the requestor. We recommend that this oral history be cited as follows: Winifred Asprey, an oral history conducted in 2007 by Viera Proulx, Computing Educators Oral History Project. Online: ceohp.org. [Context for the interview: Viera Proulx, the interviewer, is a former student of Dr. Asprey’s. Also present during the interview was Greg Priest-Dorman, who came to Vassar as a student in 1978, worked with the Computer Science Department during that time, and returned to the department in 1992; at the time of the interview, he was serving as Systems Administrator and Lab Coordinator for the Computer Sciences Department. Statements by Viera Proulx are in regular bold with the initial “V:”; statements by Greg Priest-Dorman are in bold italics and marked with the initial “G:”. -
Trees, Valuations and the Green-Lazarsfeld Set. Thomas Delzant
Trees, valuations and the Green-Lazarsfeld set. Thomas Delzant To cite this version: Thomas Delzant. Trees, valuations and the Green-Lazarsfeld set.. GAFA Geometric And Functional Analysis, 2008, pp.15. 10.1007/s00039-008-0679-2. hal-00131474 HAL Id: hal-00131474 https://hal.archives-ouvertes.fr/hal-00131474 Submitted on 16 Feb 2007 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Trees, valuations and the Green-Lazarsfeld set. Thomas Delzant∗ D´epartement de Math´ematiques, Universit´ede Strabourg 7 rue R. Descartes F-67084 Strasbourg February 16, 2007 1 Introduction. The aim of this paper is the study of the relationship between two objects, the Green-Lazarsfeld set and the Bieri Neumann Strebel invariant, which appear simultaneously in 1987 ([GL] , [BNS]). Let us recall some basic definitions. Let Γ be a finitely generated group, and K be a field. A 1-character χ is an homomorphism from Γ to K∗ ; in this article we will only consider 1-characters, and call them characters. A character χ is called exceptional if H1(Γ,χ) 6= 0, or more geometrically if χ can be realized as the linear part of a fixed point free affine action of Γ on a K-line. -
On Unit Group of Finite Semisimple Group Algebras of Non-Metabelian Groups of Order 108
ON UNIT GROUP OF FINITE SEMISIMPLE GROUP ALGEBRAS OF NON-METABELIAN GROUPS OF ORDER 108 Gaurav Mittal1; R. K. Sharma2 1Department of Mathematics, Indian Institute of Technology Roorkee, Roorkee, India 2Department of Mathematics, Indian Institute of Technology Delhi, New Delhi, India email: [email protected], [email protected] Abstract. In this paper, we characterize the unit groups of semisimple group algebras FqG of k non-metabelian groups of order 108, where Fq is a field with q = p elements for some prime p > 3 and positive integer k. Upto isomorphism, there are 45 groups of order 108 but only 4 of them are non-metabelian. We consider all the non-metabelian groups of order 108 and find the Wedderburn decomposition of their semisimple group algebras. And as a by-product obtain the unit groups. Mathematics Subject Classification (2010): 16U60, 20C05 Keywords: Unit group, Finite field, Wedderburn decomposition 1. Introduction k Let Fq denote a finite field with q = p elements for odd prime p > 3, G be a finite group and FqG be the group algebra. The study of the unit groups of group algebras is a classical problem and has applications in cryptography [4] as well as in coding theory [5] etc. For the exploration of Lie properties of group algebras and isomorphism problems, units are very useful see, e.g. [1]. We refer to [11] for elementary definitions and results about the group algebras and [2, 15] for the abelian group algebras and their units. Recall that a group G is metabelian if there is a normal subgroup N of G such that both N and G=N are abelian. -
Modules Over Crossed Products of a Division Ring by a Free Abelian Group II
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Journal of Algebra 253 (2002) 417–445 www.academicpress.com Modules over crossed products of a division ring by a free abelian group II C.J.B. Brookes a and J.R.J. Groves b,∗ a Corpus Christi College, Cambridge, CB2 1RH, United Kingdom b Department of Mathematics and Statistics, University of Melbourne, Parkville, Victoria 3010, Australia Received 30 September 2001 Communicated by Jan Saxl 1. Introduction Bieri and Strebel in [3] established a criterion describing when a finitely generated metabelian group has a finite presentation. It is expressed in terms of a subset of HomZ(A, R),whereA is the maximal free abelian quotient of the metabelian group. This ‘geometric invariant’ is related to other subsets ∆(M) of HomZ(A, R) defined for any field k, free abelian group A of finite rank and any finitely generated kA-module M. These were studied first by Bieri and Strebel and then later by Bieri and the second author. It was shown in [1] that ∆(M) is a closed polyhedron, and in [2] that the rigidity of ∆(M), under the automorphisms of HomZ(A, R) induced by those of A, is closely related to the algebraic structure of M. The automorphisms of M can therefore be successfully studied using ∆(M). For example, one may deduce that, if no non-trivial element of A has a non-zero fixed point in M and M has no non-zero submodules induced from subgroups of A of infinite index, then only a periodic automorphism γ of A may arise as a ‘twisting’ associated, via β(m.a) = β(m).γ(a) for a ∈ A and m ∈ M, with a k-automorphism β of M. -
Math 627A: Modern Algebra I
Mike O'Sullivan Department of Mathematics San Diego State University Fall 2008 Math 627A: Modern Algebra I Homework II Please read the following problems and their solutions in Ash's text. Many of them are routine, and others have been covered in class to some extent. • x1.1 pr. 2-11. • x1.2 pr. 1-8. • x1.3 pr. 1-12. • x1.4 pr. 1-9. • x1.5 pr. 1-8. Let G be a group. The following groups and subgroups are important. You should be able to establish these results. • Z(G) = fa 2 G : ag = ga for all g 2 Gg is a normal subgroup of G . • The centralizer of a 2 G , C(a) = fg 2 g : ga = agg is a subgroup of G containing T a . Z(G) = a2A C(a). −1 • Let H be a subgroup of G . The normalizer of H , NH = fx 2 G : x Hx = Hg is a subgroup of H containing H . H is normal in NH . Any subgroup K of G that contains H as a normal subgroup is contained in NH . (If N ¢ K ≤ G then K ≤ NH .) • The set of automorphisms of G , Aut(G) , is a group. • The set of inner automorphisms of G , Inn(G) is a normal subgroup of Aut(G). • If G is abelian, Tor(G) = fa 2 G : ord(a) is finite g is a normal subgroup of G and G= Tor(G) has no elements of finite order. • (harder) The commutator subgroup of G , is the subgroup G0 of G generated by S = faba−1b−1 : a; b 2 Gg . -
The Twisted Conjugacy Problem for Endomorphisms of Metabelian Groups ∗ E
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by UPCommons. Portal del coneixement obert de la UPC Algebra and Logic, Vol. 48, No. 2, 2009 THE TWISTED CONJUGACY PROBLEM FOR ENDOMORPHISMS OF METABELIAN GROUPS ∗ E. Ventura1 andV.A.Roman’kov2 UDC 512.54 Keywords: metabelian group, twisted conjugacy, endomorphism, fixed points, Fox derivatives. Let M be a finitely generated metabelian group explicitly presented in a variety A2 of all metabelian groups. An algorithm is constructed which, for every endomorphism ϕ ∈ End(M) identical modulo an Abelian normal subgroup N containing the derived subgroup M and for any pair of elements u, v ∈ M, decides if an equation of the form (xϕ)u = vx has a solution in M. Thus, it is shown that the title problem under the assumptions made is algorithmically decidable. Moreover, the twisted conjugacy problem in any polycyclic metabelian group M is decidable for an arbitrary endomorphism ϕ ∈ End(M). INTRODUCTION Let G be a group and ϕ ∈ End(G) an endomorphism. We say that elements u, v ∈ G are ϕ-twisted conjugate, or, merely, are ϕ-conjugate, if and only if there exists an element x ∈ G such that (xϕ)u = vx. It is easy to see that the property of being ϕ-conjugate is an equivalence relation u ∼ϕ v.Forϕ =id,the relation turns into the usual conjugacy u ∼ v. Defining a left action of G on its basic set by x · u =(xϕ)ux−1, we can conclude that the orbits coincide with the equivalence classes defined immediately above. -
Metabelian Groups of Order at Most 24
Menemui Matematik (Discovering Mathematics) Vol. 34 No. 1: 77 – 93 (2012) Metabelian Groups of Order at Most 24 Siti Fatimah Abdul Rahman1 and Nor Haniza Sarmin2 1Department of Mathematics, Faculty of Computer Science and Mathematics, Universiti Teknologi MARA Perlis, 02600 Arau, Perlis [email protected] 2Department of Mathematics, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor. [email protected] ABSTRACT A group G is metabelian if there exists a normal subgroup A in G such that both A and the factor group, G / A are abelian. Equivalently, G is metabelian if and only if the commutator subgroup [G, G] is abelian. The main objective of this research is to determine all metabelian groups of order at most 24. In this research, some basic concepts of metabelian groups will be presented and the determinations of metabelian groups are done based on their definition and some theorems. The Groups, Algorithms and Programming (GAP) software have been used to find the multiplication table for some groups. Keywords: Metabelian, Commutator subgroup. INTRODUCTION Metabelian groups are groups that are close to being abelian, in the sense that every abelian group is metabelian, but not every metabelian group is abelian. This closeness is reflected in the particular structure of their commutator subgroups. In the Russian mathematical literature, by a metabelian group one sometimes means a nilpotent group of nilpotency class two (Kurosh, 1955). The term metabelian was earlier used for groups of nilpotency class two, but is no longer used in that sense. Sometimes, the term metabelian or derived length two or solvable length two is used specifically for a metabelian group whose derived length is precisely two, i.e., a nonabelian metabelian group. -
The Relative Commutativity Degree and Sub-Multiplicative Degree for Noncyclic Subgroups of Some Nonabelian Metabelian Groups
THE RELATIVE COMMUTATIVITY DEGREE AND SUB-MULTIPLICATIVE DEGREE FOR NONCYCLIC SUBGROUPS OF SOME NONABELIAN METABELIAN GROUPS FADHILAH BINTI ABU BAKAR UNIVERSITI TEKNOLOGI MALAYSIA THE RELATIVE COMMUTATIVITY DEGREE AND SUB-MULTIPLICATIVE DEGREE FOR NONCYCLIC SUBGROUPS OF SOME NONABELIAN METABELIAN GROUPS FADHILAH ABU BAKAR A dissertation submitted in partial fulfilment of the requirements for the award of the degree of Master of Science Faculty of Science Universiti Teknologi Malaysia APRIL 2017 iii To my beloved Ummi and Abah iv ACKNOWLEDGEMENTS In the name of Allah, the Most Gracious and Merciful. He has given me strength and courage to accomplish this dissertation. I would like to take this opportunity to express my utmost gratitude to everyone involved in completing this dissertation. High appreciation to my dissertation supervisor, Dr. Nor Muhainiah Mohd Ali for her effort and patience in guiding me to conduct this research. Thanks a lot for all the encouragement, critisms and suggestions. I am also indebted to Ministry of Higher Education (MOHE) Malaysia for sponsoring my master study through MyBrain’ 15 scholarship. My special thanks to my family especially my parents, Zubidah binti Abu Bakar and Abu Bakar bin Mohammad for their full encouragement, support and inspiration while completing this dissertation. Last but not least, I would like to thank my close friends, Fasihah Zulkiflee and Amira Fadina Ahmad Fadzil for their assistance and encouragement throughout the process of completing this dissertation. v ABSTRACT A metabelian group is a group G that has at least an abelian normal subgroup N such that the quotient group G/n is also abelian. The concept of commutativity degree plays an important role in determining the abelianness of the group. -
The American Mathematical Society
THE AMERICAN MATHEMATICAL SOCIETY Edited by John W. Green and Gordon L. Walker CONTENTS MEETINGS Calendar of Meetings . • . • . • . • . • • • . • . 168 PRELIMINARY ANNOUNCEMENT OF MEETING...................... 169 DOCTORATES CONFERRED IN 1961 ••••••••••••••••••••••••••••.•• 173 NEWS ITEMS AND ANNOUNCEMENTS • • • • • • • • • • • • • • • • • • • 189, 194, 195, 202 PERSONAL ITEMS •••••••••••••••••••••••••••••••.••••••••••• 191 NEW AMS PUBLICATIONS •••••••••••••••••••••••••••••••••••.•• 195 LETTERS TO THE EDITOR •.•.•.•••••••••.•••••.••••••••••••••• 196 MEMORANDA TO MEMBERS The Employment Register . • . • . • . • • . • . • • . • . • . • 198 Dues of Reciprocity Members of the Mathematical Society of Japan • . • . • . 198 SUPPLEMENTARY PROGRAM -No. 11 ••••••••••••••••••••••••••••• 199 ABSTRACTS OF CONTRIBUTED PAPERS •.•••••••••••.••••••••••••• 203 ERRATA •••••••••••••••••••••••••••••••••••••••••••••••.• 231 INDEX TO ADVERTISERS • • • • • • • • • • • • • . • . • • • • • • • • • • • . • • • • • • • • • • 243 RESERVATION FORM •••.•.•••••••••••.•••••••••••.••••••••••• 243 MEETINGS CALENDAR OF MEETINGS NOTE: This Calendar lists all of the meetings which have been approved by the Council up to the date a~ch this issue of the NOTICES was sent to press. The summer and annual meetings are joint meetings of the Mathematical Association of America and the American Mathematical Society. The meeting dates which fall rather far in the future are subject to change. This is particularly true of the meetings to which no numbers have yet been assigned. Meet- -
Quaderni Del Trentennale 1975-2005
ISTITUTO ITALIANO PER GLI STUDI FILOSOFICI QUADERNI DEL TRENTENNALE 1975-2005 3 1 2 ISTITUTO ITALIANO PER GLI STUDI FILOSOFICI LEZIONI DI PREMI NOBEL Nella sede dell’Istituto Napoli 2005 3 A cura di Antonio Gargano, Segretario generale dell’Istituto Italiano per gli Studi Filosofici @ Istituto Italiano per gli Studi Filosofici Palazzo Serra di Cassano Napoli, Via Monte di Dio 14 4 INDICE PREMESSA 7 EDUARDO CAIANIELLO, Napoli perla della scienza 23 AUGUSTO GRAZIANI, Introduction to the essays of Kenneth J. Arrow 29 KENNETH J. ARROW, The Economics of Information 35 KENNETH J. ARROW, General Equilibrium and Economic Growth 47 SHELDON L. GLASHOW, La sfida della fisica delle particelle elementari 55 FRANCESCO NICODEMI, Premessa al testo di David Gross 57 DAVID GROSS, Unified Theories of Everything 63 DAVID GROSS, Teorie unificate del tutto 83 MAX F. P ERUTZ, Emoglobina, una molecola vivente 101 ILYA PRIGOGINE, Vers un humanisme scientifique 105 RITA LEVI MONTALCINI, Un nuovo ordine internazionale per la sicurezza dell’umanità 119 AUGUSTO GRAZIANI, Premessa al testo di James Tobin 123 JAMES TOBIN, Price Flexibility and Full Employment. The Debate Then and Now 133 5 SEMINARI E GIORNATE DI STUDIO DI SCIENZE E STORIA DELLE SCIENZE 147 SEMINARI E GIORNATE DI STUDIO DI STORIA E TEORIA ECONOMICA 331 6 PREMESSA L’Istituto Italiano per gli Studi Filosofici fin dalla sua fondazione ha costantemente affiancato alle attività di formazione e di ricerca in ambito filosofico e storico iniziative di ampio respiro nel campo delle scienze matematiche e naturali, persuaso della fondamentale unità della conoscenza nella ricerca della verità. Proprio al tema Unity and Internationalism of the Sciences and Humanities l’Istituto dedicò un convegno nella sede del CERN a Ginevra, alla presenza di Edoardo Amaldi. -
EPADEL a Semisesquicentennial History, 1926-2000
EPADEL A Semisesquicentennial History, 1926-2000 David E. Zitarelli Temple University An MAA Section viewed as a microcosm of the American mathematical community in the twentieth century. Raymond-Reese Book Company Elkins Park PA 19027 Author’s address: David E. Zitarelli Department of Mathematics Temple University Philadelphia, PA 19122 e-mail: [email protected] Copyright © (2001) by Raymond-Reese Book Company, a division of Condor Publishing, Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photography, recording, or any information storage retrieval system, without written permission from the publisher. Requests for permission to make copies of any part of the work should be mailed to Permissions, Raymond-Reese Book Company, 307 Waring Road, Elkins Park, PA 19027. Printed in the United States of America EPADEL: A Sesquicentennial History, 1926-2000 ISBN 0-9647077-0-5 Contents Introduction v Preface vii Chapter 1: Background The AMS 1 The Monthly 2 The MAA 3 Sections 4 Chapter 2: Founding Atlantic Apathy 7 The First Community 8 The Philadelphia Story 12 Organizational Meeting 13 Annual Meeting 16 Profiles: A. A. Bennett, H. H. Mitchell, J. B. Reynolds 21 Chapter 3: Establishment, 1926-1932 First Seven Meetings 29 Leaders 30 Organizational Meeting 37 Second Meeting 39 Speakers 40 Profiles: Arnold Dresden, J. R. Kline 48 Chapter 4: Émigrés, 1933-1941 Annual Meetings 53 Leaders 54 Speakers 59 Themes of Lectures 61 Profiles: Hans Rademacher, J. A. Shohat 70 Chapter 5: WWII and its Aftermath, 1942-1955 Annual Meetings 73 Leaders 76 Presenters 83 Themes of Lectures 89 Profiles: J.