English

Groups not presentable by products

Group Theory 2013-02-11 v2 Geometric Topology

Abstract

In this paper we study obstructions to presentability by products for finitely generated groups. Along the way we develop both the concept of acentral subgroups, and the relations between presentability by products on the one hand, and certain geometric and measure or orbit equivalence invariants of groups on the other. This leads to many new examples of groups not presentable by products, including all groups with infinitely many ends, the (outer) automorphism groups of free groups, Thompson's groups, and even some elementary amenable groups.

Keywords

Cite

@article{arxiv.1003.3853,
  title  = {Groups not presentable by products},
  author = {D. Kotschick and C. Loeh},
  journal= {arXiv preprint arXiv:1003.3853},
  year   = {2013}
}

Comments

25 pages, minor changes, to appear in Groups, Geometry, and Dynamics

R2 v1 2026-06-21T15:00:01.461Z