English

Extending group actions on metric spaces

Group Theory 2018-08-14 v3 Geometric Topology

Abstract

We address the following natural extension problem for group actions: Given a group GG, a subgroup HGH\le G, and an action of HH on a metric space, when is it possible to extend it to an action of the whole group GG on a (possibly different) metric space? When does such an extension preserve interesting properties of the original action of HH? We begin by formalizing this problem and present a construction of an induced action which behaves well when HH is hyperbolically embedded in GG. Moreover, we show that induced actions can be used to characterize hyperbolically embedded subgroups. We also obtain some results for elementary amenable groups.

Keywords

Cite

@article{arxiv.1703.03010,
  title  = {Extending group actions on metric spaces},
  author = {C. Abbott and D. Hume and D. Osin},
  journal= {arXiv preprint arXiv:1703.03010},
  year   = {2018}
}
R2 v1 2026-06-22T18:40:09.974Z