English

The first $\ell^2$-Betti number and groups acting on trees

Group Theory 2023-01-30 v1

Abstract

We generalise results of Thomas, Allcock, Thom-Petersen, and Kar-Niblo to the first 2\ell^2-Betti number of quotients of certain groups acting on trees by subgroups with free actions on the edge sets of the graphs.

Cite

@article{arxiv.2012.13368,
  title  = {The first $\ell^2$-Betti number and groups acting on trees},
  author = {Indira Chatterji and Sam Hughes and Peter Kropholler},
  journal= {arXiv preprint arXiv:2012.13368},
  year   = {2023}
}

Comments

6 pages

R2 v1 2026-07-22T20:51:53.987Z