{ "id": "1703.03010", "version": "v1", "published": "2017-03-08T19:50:53.000Z", "updated": "2017-03-08T19:50:53.000Z", "title": "Extending group actions on metric spaces", "authors": [ "C. Abbott", "D. Hume", "D. Osin" ], "categories": [ "math.GR", "math.GT" ], "abstract": "We address the following natural extension problem for group actions: Given a group $G$, a subgroup $H\\le G$, and an action of $H$ on a metric space, when is it possible to extend it to an action of the whole group $G$ on a (possibly different) metric space? When does such an extension preserve interesting properties of the original action of $H$? We begin by formalizing this problem and present a construction of an induced action which behaves well when $H$ is hyperbolically embedded in $G$. Moreover, we show that induced actions can be used to characterize hyperbolically embedded subgroups. We also obtain some results for elementary amenable groups.", "revisions": [ { "version": "v1", "updated": "2017-03-08T19:50:53.000Z" } ], "analyses": { "keywords": [ "metric space", "extending group actions", "natural extension problem", "extension preserve interesting properties", "induced action" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }