Weak commutativity and finiteness properties of groups
arXiv:1706.06937 · doi:10.1112/blms.12219
Abstract
We consider the group obtained from by forcing each element in the first free factor to commute with the copy of in the second free factor. Deceptively complicated finitely presented groups arise from this construction: is finitely presented if and only if is finitely presented, but if is a non-abelian free group of finite rank then has a subgroup of finite index whose third homology is not finitely generated.
12 pages, 2 figures. Final version to appear in Bulletin of the London Math Soc