{ "id": "1312.6027", "version": "v2", "published": "2013-12-20T16:41:21.000Z", "updated": "2014-12-06T13:29:49.000Z", "title": "Universal properties of group actions on locally compact spaces", "authors": [ "Hiroki Matui", "Mikael Rordam" ], "comment": "42 pages", "categories": [ "math.GR", "math.OA" ], "abstract": "We study universal properties of locally compact G-spaces for countable infinite groups G. In particular we consider open invariant subsets of the \\beta-compactification of G (which is a G-space in a natural way), and their minimal closed invariant subspaces. These are locally compact free G-spaces, and the latter are also minimal. We examine the properies of these G-spaces with emphasis on their universal properties. As an example of our resuts, we use combinatorial methods to show that each countable infinite group admits a free minimal action on the locally compact non-compact Cantor set.", "revisions": [ { "version": "v1", "updated": "2013-12-20T16:41:21.000Z", "abstract": "We study universal properties of locally compact G-spaces, where G is a countable infinite group. In particular, we consider open invariant subsets of the \\beta-compactification of G (which is a G-space in a natural way), and we show that these have a universal property among locally compact G-spaces of a given type (to be defined). We prove universality and uniqueness results for the closed invariant subsets of the above mentioned open invariant subsets of the \\beta-compactification of G. We use combinatorial methods to show that each countable infinite group admits a free minimal action on the locally compact non-compact Cantor set.", "comment": "43 pages", "journal": null, "doi": null }, { "version": "v2", "updated": "2014-12-06T13:29:49.000Z" } ], "analyses": { "subjects": [ "43A07", "46L55", "22F05" ], "keywords": [ "universal properties", "locally compact spaces", "group actions", "countable infinite group", "locally compact non-compact cantor set" ], "note": { "typesetting": "TeX", "pages": 42, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1312.6027M" } } }