English

Engel sinks of fixed points in finite groups

Group Theory 2018-09-11 v1

Abstract

For an element gg of a group GG, an Engel sink is a subset E(g)\mathscr{E}(g) such that for every xG x\in G all sufficiently long commutators [x,g,g,,g] [x,g,g,\ldots,g] belong to E(g)\mathscr{E}(g). Let qq be a prime, let mm be a positive integer and AA an elementary abelian group of order q2q^2 acting coprimely on a finite group GG. We show that if for each nontrivial element aa in A A and every element gCG(a)g\in C_{G}(a) the cardinality of the smallest Engel sink E(g)\mathscr{E}(g) is at most mm, then the order of γ(G)\gamma_\infty(G) is bounded in terms of mm only. Moreover we prove that if for each aA{1}a\in A\setminus \{1\} and every element gCG(a)g\in C_{G}(a), the smallest Engel sink E(g)\mathscr{E}(g) generates a subgroup of rank at most mm, then the rank of γ(G)\gamma_\infty(G) is bounded in terms of mm and qq only.

Keywords

Cite

@article{arxiv.1809.02733,
  title  = {Engel sinks of fixed points in finite groups},
  author = {Cristina Acciarri and Pavel Shumyatsky and Danilo Sanção da Silveira},
  journal= {arXiv preprint arXiv:1809.02733},
  year   = {2018}
}