5 papers · 1 filter
A Hirsch length inequality
Sam Tertooy
Let and be subgroups of a virtually polycyclic group . We prove the Hirsch length inequality We show that equality holds when the num…
Class numbers and nilpotent subgroups of
Sam Tertooy
We show that for certain odd prime powers , the number of conjugacy classes of is greater than the order of its largest nilpotent subgroup. This answers nega…
Bi-twisted conjugacy in finite groups
Pieter Senden, Sam Tertooy
We provide two alternative ways to determine the number of bi-twisted conjugacy classes in a finite group: one using irreducible characters and one using ordinary conjugacy classes…
Algorithms for twisted conjugacy classes of polycyclic-by-finite groups II
Sam Tertooy
We construct an algorithm that, given a pair of homomorphisms between polycyclic-by-finite groups, determines whether their Reidemeister number is finite, and if so returns a set o…
Extreme Reidemeister spectra of finite groups
Sam Tertooy
We extend the notions of "-property" and "full (extended) Reidemeister spectrum" to finite groups in a meaningful way. We provide examples of finite groups admitting thes…