On the congruence subgroup problem for branch groups
Group Theory
2016-10-19 v2
Abstract
We answer a question of Bartholdi, Siegenthaler and Zalesskii, showing that the congruence subgroup problem for branch groups is independent of the branch action on a tree. We prove that the congruence topology of a branch group is determined by the group; specifically, by its structure graph, an object first introduced by Wilson. We also give a more natural definition of this graph.
Keywords
Cite
@article{arxiv.1405.3237,
title = {On the congruence subgroup problem for branch groups},
author = {Alejandra Garrido},
journal= {arXiv preprint arXiv:1405.3237},
year = {2016}
}
Comments
9 pages, no figures; minor changes in accordance with referee report, exposition improved