Abstract
We address the following natural extension problem for group actions: Given a group G, a subgroup H <= 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.