Topological dynamics beyond Polish groups

Abstract

When $G$ is a Polish group, metrizability of the universal minimal flow has been shown to be a robust dividing line in the complexity of the topological dynamics of $G$. We introduce a class of groups, the CAP groups, which provides a neat generalization of this dividing line to all topological groups. We prove a number of characterizations of this class, having very different flavors, and use these to prove that the class of CAP groups enjoys a number of nice closure properties. As a concrete application, we compute the universal minimal flow of the homeomorphism groups of several scattered topological spaces, building on recent work of Gheysens.

Version accepted for publication in Commentarii Mathematici Helvetici (CMH)

References in corpus (1)

• Topometric spaces and perturbations of metric structures

Cited by in corpus (3)

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