Weakly maximal subgroups in regular branch groups
Group Theory
2017-05-30 v3
Abstract
Let be a finitely generated regular branch group acting by automorphisms on a regular rooted tree . It is well-known that stabilizers of infinite rays in (aka parabolic subgroups) are weakly maximal subgroups in , that is, maximal among subgroups of infinite index. We show that, given a finite subgroup , possesses uncountably many automorphism equivalence classes of weakly maximal subgroups containing . In particular, for Grigorchuk-Gupta-Sidki type groups this implies that they have uncountably many automorphism equivalence classes of weakly maximal subgroups that are not parabolic.
Cite
@article{arxiv.1502.07283,
title = {Weakly maximal subgroups in regular branch groups},
author = {Khalid Bou-Rabee and Paul-Henry Leemann and Tatiana Nagnibeda},
journal= {arXiv preprint arXiv:1502.07283},
year = {2017}
}
Comments
11 pages; a few corrections; to appear in J. Algebra