A finitely generated branch group of exponential growth without free subgroups
Group Theory
2012-09-25 v2
Abstract
We will give an example of a branch group that has exponential growth but does not contain any non-abelian free subgroups. This answers question 16 from \cite{Bartholdi} positively. The proof demonstrates how to construct a non-trivial word for any such that . The group is not just-infinite. We prove that every normal subgroup of is finitely generated as an abstract group and every proper quotient soluble. Further, has infinite virtual first Betti number but is not large.
Cite
@article{arxiv.1207.6548,
title = {A finitely generated branch group of exponential growth without free subgroups},
author = {Elisabeth Fink},
journal= {arXiv preprint arXiv:1207.6548},
year = {2012}
}
Comments
16 pages, 1 figure