English

Thompson-like groups, Reidemeister numbers, and fixed points

Group Theory 2023-10-20 v3

Abstract

We investigate fixed-point properties of automorphisms of groups similar to R. Thompson's group FF. Revisiting work of Gon\c{c}alves-Kochloukova, we deduce a cohomological criterion to detect infinite fixed-point sets in the abelianization, implying the so-called property RR_\infty. Using the BNS Σ\Sigma-invariant and drawing from works of Gon\c{c}alves-Sankaran-Strebel and Zaremsky, we show that our tool applies to many FF-like groups, including Stein's F2,3F_{2,3}, Cleary's FτF_\tau, the Lodha-Moore groups, and the braided version of FF.

Keywords

Cite

@article{arxiv.2105.07096,
  title  = {Thompson-like groups, Reidemeister numbers, and fixed points},
  author = {Paula Macedo Lins de Araujo and Altair Santos de Oliveira-Tosti and Yuri Santos Rego},
  journal= {arXiv preprint arXiv:2105.07096},
  year   = {2023}
}

Comments

v3: 25 pages, 4 figures; Incorporated referees' suggestions, corrected Proposition 2.7, included new remarks. Final version, to appear in Geometriae Dedicata

R2 v1 2026-06-24T02:07:58.581Z