English

Quasi-isometric rigidity for graphs of virtually free groups with two-ended edge groups

Group Theory 2021-10-29 v3

Abstract

We study the quasi-isometric rigidity of a large family of finitely generated groups that split as graphs of groups with virtually free vertex groups and two-ended edge groups. Let GG be a group that is one-ended, hyperbolic relative to virtually abelian subgroups, and has JSJ decomposition over two-ended subgroups containing only virtually free vertex groups that aren't quadratically hanging. Our main result is that any group quasi-isometric to GG is abstractly commensurable to GG. In particular, our result applies to certain "generic" HNN extensions of a free group over cyclic subgroups.

Keywords

Cite

@article{arxiv.2007.10034,
  title  = {Quasi-isometric rigidity for graphs of virtually free groups with two-ended edge groups},
  author = {Sam Shepherd and Daniel J. Woodhouse},
  journal= {arXiv preprint arXiv:2007.10034},
  year   = {2021}
}

Comments

53 pages, 3 figures; v2: minor changes including to the statement of Theorem 1.3; v3: minor changes following referee's comments; to appear in Crelles