English

On maximal subgroups of infinite index in branch and weakly branch groups

Group Theory 2020-04-06 v1

Abstract

We generalise a technical tool, originally developed by Pervova for the study of maximal subgroups in Grigorchuk and GGS groups, to all weakly branch groups satisfying a natural condition, and in particular to all branch groups. We then use this tool to prove that every maximal subgroup of infinite index of a branch group is also a branch group. As a further application of this result, we show that every maximal subgroup of the Basilica group is of finite index.

Keywords

Cite

@article{arxiv.2004.01696,
  title  = {On maximal subgroups of infinite index in branch and weakly branch groups},
  author = {Dominik Francoeur},
  journal= {arXiv preprint arXiv:2004.01696},
  year   = {2020}
}

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27 pages