{ "id": "2401.08440", "version": "v2", "published": "2024-01-16T15:37:42.000Z", "updated": "2024-09-17T07:22:12.000Z", "title": "Local mean dimension theory for sofic group actions", "authors": [ "Felipe GarcĂ­a-Ramos", "Yonatan Gutman" ], "comment": "to appear in GGD", "categories": [ "math.DS" ], "abstract": "Using a local perspective, we introduce \\textit{mean dimension pairs} and give sufficient conditions of when every non-trivial factor of a continuous group action of a sofic group $G$ has positive mean dimension. In addition we show that the mean dimension map is Borel, and that the set of subshifts with completely positive mean dimension of $[0,1]^G$, the full $G$-shift on the interval, is a complete coanalytic set in the set of all subshifts (hence not Borel). Our results are new even when the acting group is $\\Z$.", "revisions": [ { "version": "v2", "updated": "2024-09-17T07:22:12.000Z" } ], "analyses": { "subjects": [ "37B05", "37B40", "54H05" ], "keywords": [ "local mean dimension theory", "sofic group actions", "positive mean dimension", "mean dimension map", "complete coanalytic set" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }