{ "id": "1210.5804", "version": "v5", "published": "2012-10-22T04:58:58.000Z", "updated": "2013-06-10T20:03:34.000Z", "title": "Syndetic submeasures and partitions of $G$-spaces and groups", "authors": [ "Taras Banakh", "Igor Protasov", "Sergiy Slobodianiuk" ], "comment": "8 pages", "categories": [ "math.GR", "math.GN" ], "abstract": "We prove that for every number k each countable infinite group $G$ admits a partition $G=A\\cup B$ into two sets which are $k$-meager in the sense that for every $k$-element subset $K\\subset G$ the sets $KA$ and $KB$ are not thick. The proof is based on the fact that $G$ possesses a syndetic submeasure, i.e., a left-invariant submeasure $\\mu:\\mathcal P(G)\\to[0,1]$ such that for each $\\epsilon > 1/|G|$ and subset $A\\subset G$ with $\\mu(A)<1$ there is a set $B\\subset G\\setminus A$ such that $\\mu(B)<\\epsilon$ and $FB=G$ for some finite subset $F\\subset G$.", "revisions": [ { "version": "v5", "updated": "2013-06-10T20:03:34.000Z" } ], "analyses": { "subjects": [ "43A07", "05B40", "20F24", "28C10", "54H11" ], "keywords": [ "syndetic submeasure", "countable infinite group", "finite subset", "left-invariant submeasure", "element subset" ], "note": { "typesetting": "TeX", "pages": 8, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1210.5804B" } } }