A counterexample to the first Zassenhaus conjecture

Eisele, F. and Margolis, L. (2018) A counterexample to the first Zassenhaus conjecture. Advances in Mathematics, 339, pp. 599-641. (doi: 10.1016/j.aim.2018.10.004)

[img]
Preview
Text
177223.pdf - Accepted Version
Available under License Creative Commons Attribution Non-commercial No Derivatives.

525kB

Abstract

Hans J. Zassenhaus conjectured that for any unit u of finite order in the integral group ring of a finite group G there exists a unit a in the rational group algebra of G such that a−1 · u · a = ±g for some g ∈ G. We disprove this conjecture by first proving general results that help identify counterexamples and then providing an infinite number of examples where these results apply. Our smallest example is a metabelian group of order 2⁷ · 3² · 5 · 7² · 19² whose integral group ring contains a unit of order 7 · 19 which, in the rational group algebra, is not conjugate to any element of the form ±g.

Item Type:Articles
Additional Information:The first author was supported by the EPSRC, grant EP/M02525X/1. The second author was supported by a Marie Curie Individual Fellowship from the European Commissions H2020 project 705112-ZC and the FWO (Research Foundation Flanders).
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Eisele, Dr Florian
Authors: Eisele, F., and Margolis, L.
College/School:College of Science and Engineering > School of Mathematics and Statistics
Journal Name:Advances in Mathematics
Publisher:Elsevier
ISSN:0001-8708
ISSN (Online):1090-2082
Published Online:04 October 2018
Copyright Holders:Copyright © 2018 Elsevier Inc.
First Published:First published in Advances in Mathematics 339: 599-641
Publisher Policy:Reproduced in accordance with the publisher copyright policy

University Staff: Request a correction | Enlighten Editors: Update this record