English

On subgroups of finite index in branch groups

Group Theory 2014-05-19 v2

Abstract

We give a structural description of the normal subgroups of subgroups of finite index in branch groups in terms of rigid stabilizers. This gives further insight into the structure lattices of branch groups introduced by the second author. We derive a condition concerning abstract commensurability of branch groups acting on the p-ary tree for any prime p.

Keywords

Cite

@article{arxiv.1301.6419,
  title  = {On subgroups of finite index in branch groups},
  author = {Alejandra Garrido and John S. Wilson},
  journal= {arXiv preprint arXiv:1301.6419},
  year   = {2014}
}

Comments

9 pages, no figures; minor changes made following referees suggestions, some explanations improved