Almost elusive permutation groups
Abstract
Let be a nontrivial transitive permutation group on a finite set . An element of is said to be a derangement if it has no fixed points on . From the orbit counting lemma, it follows that contains a derangement, and in fact contains a derangement of prime power order by a theorem of Fein, Kantor and Schacher. However, there are groups with no derangements of prime order; these are the so-called elusive groups and they have been widely studied in recent years. Extending this notion, we say that is almost elusive if it contains a unique conjugacy class of derangements of prime order. In this paper we first prove that every quasiprimitive almost elusive group is either almost simple or -transitive of affine type. We then classify all the almost elusive groups that are almost simple and primitive with socle an alternating group, a sporadic group, or a rank one group of Lie type.
Cite
@article{arxiv.2010.02652,
title = {Almost elusive permutation groups},
author = {Timothy C. Burness and Emily V. Hall},
journal= {arXiv preprint arXiv:2010.02652},
year = {2021}
}
Comments
19 pages, to appear in J. Algebra