Finding possible permutation characters
type: Item
instance of: scholarly article
title: Finding possible permutation characters
zbMATH Open document ID: 0921.20013
author: Thomas Breuer
author: Götz Pfeiffer
published in: Journal of Symbolic Computation
publication date: 1999-08-09T00:00:00Z
review text: The authors describe three different methods to compute all those characters of a finite group that have certain properties of transitive permutation characters. It is assumed that all rationally irreducible characters of the group are known in advance. All methods check which sums of integral multiples of these are possible permutation characters. First, a combinatorial approach can be used to enumerate the vectors of multiplicities. Secondly, these characters can be found as integral solutions of a system of inequalities. Thirdly, they are calculated via Gaussian elimination after prescribing a permutation character value on a certain conjugacy class. The methods are used to determine these characters for some finite groups and runtimes of GAP [\textit{M. Schönert}, et al., GAP -- Groups, Algorithms and Programming. Lehrstuhl D für Mathematik, RWTH Aachen (1994)], version 3.4 are listed. Often the second method is faster than the first. Gaussian elimination appears to be more efficient only for permutation characters of larger degree. In the final section, the permutation character of the Lyons group operating on cosets of a maximal subgroup of type \(3^{2+4}:2A_5.D_8\) is constructed. The authors explain the interaction between their methods to find possible permutation characters and further reduction of these by additional knowledge in detail in this example and construct the character.
Mathematics Subject Classification ID: 20C40
Mathematics Subject Classification ID: 20C15
Mathematics Subject Classification ID: 20C34
Mathematics Subject Classification ID: 68W30
Mathematics Subject Classification ID: 20-04
zbMATH DE Number: 1206968
zbMATH Keywords: possible permutation characters
zbMATH Keywords: vectors of multiplicities
zbMATH Keywords: transitive permutation characters
zbMATH Keywords: characters of finite groups
zbMATH Keywords: Gaussian elimination
zbMATH Keywords: integral solutions of systems of inequalities
zbMATH Keywords: Lyons group
zbMATH Keywords: GAP
zbMATH Keywords: irreducible characters
describes a project that uses: GAP
MaRDI profile type: Publication
full work available at URL: jsco.1998.0217
OpenAlex ID: W2035988237
DOI: 10.1006/JSCO.1998.0217
description: scientific article; zbMATH DE number 1206968