On the structure of finitely generated subgroups of branch groups
Dominik Francoeur
Universidad Autónoma de Madrid, Madrid, SpainRostislav Grigorchuk
Texas A&M University, College Station, USAPaul-Henry Leemann
Xi’an Jiaotong-Liverpool University, Suzhou, P. R. ChinaTatiana Nagnibeda
Université de Genève, Geneva, Switzerland

Abstract
Motivated by the study of profinite topology in branch groups, we prove a structural result about their finitely generated subgroups. More precisely, we show that finitely generated subgroups of a branch group with the subgroup induction property have a block structure, which roughly means that, up to a finite index, they are products of finite index subgroups, embedded in the group in a way that is coherent with its branch action on the rooted tree.
Cite this article
Dominik Francoeur, Rostislav Grigorchuk, Paul-Henry Leemann, Tatiana Nagnibeda, On the structure of finitely generated subgroups of branch groups. J. Comb. Algebra (2025), published online first
DOI 10.4171/JCA/112