When is the search of relatively maximal subgroups reduced to quotients?
Abstract
Let be a class of finite groups closed under taking subgroups, homomorphic images, and extensions. Denote by the number of conjugacy classes -maximal subgroups of a finite group . The natural problem to describe up to conjugacy -maximal subgroups of a given finite group is complicated by the fact that it is not inductive. In particular, generally speaking, the image of an -maximal subgroup is not -maximal in the image of a homomorphism. Nevertheless, there are group homomorphisms which preserve the number of conjugacy classes of -maximal subgroups (for example, the homomorphisms whose kernels are -groups). Under such homomorphisms, the image of an -maximal subgroup is always -maximal and, moreover, there is a natural bijection between the conjugacy classes of -maximal subgroups of the image and preimage. All such homomorphisms are completely described in the paper. More precisely, it is proved that, for a homomorphism from a group , the equality holds if and only if , which in turn is equivalent to the fact that the composition factors of the kernel of belong to an explicitly given list.
Keywords
Cite
@article{arxiv.2110.15638,
title = {When is the search of relatively maximal subgroups reduced to quotients?},
author = {Wenbin Guo and Danila O. Revin},
journal= {arXiv preprint arXiv:2110.15638},
year = {2023}
}
Comments
in Russian