On the structure of finitely generated subgroups of branch groups

Abstract

We describe the block structure of finitely generated subgroups of branch groups with the so-called subgroup induction property, including the first Grigorchuk group $\mathcal{G}$ and the torsion GGS groups.

35 pages, 3 figures. v2: Final version. The proof of Theorem 6.13 was proving a little bit more than announced, this is now made explicit in remark 6.16