English

Right Engel-type subgroups and length parameters of finite groups

Group Theory 2020-12-09 v1

Abstract

Let gg be an element of a finite group GG and let Rn(g)R_{n}(g) be the subgroup generated by all the right Engel values [g,nx][g,{}_{n}x] over xGx\in G. In the case when GG is soluble we prove that if, for some nn, the Fitting height of Rn(g)R_{n}(g) is equal to kk, then gg belongs to the (k+1)(k+1)th Fitting subgroup Fk+1(G)F_{k+1}(G). For nonsoluble GG, it is proved that if, for some nn, the generalized Fitting height of Rn(g)R_n(g) is equal to kk, then gg belongs to the generalized Fitting subgroup Ff(k,m)(G)F^*_{f(k,m)}(G) with f(k,m)f(k,m) depending only on kk and mm, where g|g| is the product of mm primes counting multiplicities. It is also proved that if, for some nn, the nonsoluble length of Rn(g)R_n(g) is equal to kk, then gg belongs to a normal subgroup whose nonsoluble length is bounded in terms of kk and mm. Earlier similar generalizations of Baer's theorem (which states that an Engel element of a finite group belongs to the Fitting subgroup) were obtained by the first two authors in terms of left Engel-type subgroups.

Keywords

Cite

@article{arxiv.1807.10624,
  title  = {Right Engel-type subgroups and length parameters of finite groups},
  author = {E. I. Khukhro and P. Shumyatsky and G. Traustason},
  journal= {arXiv preprint arXiv:1807.10624},
  year   = {2020}
}

Comments

arXiv admin note: text overlap with arXiv:1506.00233