{ "id": "1512.03130", "version": "v1", "published": "2015-12-10T02:53:09.000Z", "updated": "2015-12-10T02:53:09.000Z", "title": "Every finite subset of an abelian group is an asymptotic approximate group", "authors": [ "Melvyn B. Nathanson" ], "comment": "14 pages", "categories": [ "math.NT" ], "abstract": "If $A$ is a nonempty subset of an additive group $G$, then the $h$-fold sumset is \\[ hA = \\{x_1 + \\cdots + x_h : x_i \\in A_i \\text{ for } i=1,2,\\ldots, h\\}. \\] The set $A$ is an $(r,\\ell)$-approximate group in $G$ if $A$ is a nonempty subset of a group $G$ and there exists a subset $X$ of $G$ such that $|X| \\leq \\ell$ and $rA \\subseteq XA$. We do not assume that $A$ contains the identity, nor that $A$ is symmetric, nor that $A$ is finite. The set $A$ is an asymptotic $(r,\\ell)$-approximate group if the sumset $hA$ is an $(r,\\ell)$-approximate group for all sufficiently large $h$. It is proved that every polytope in a real vector space is an asymptotic $(r,\\ell)$-approximate group, that every finite set of lattice points is an asymptotic $(r,\\ell)$-approximate group, and that every finite subset of an abelian group is an asymptotic $(r,\\ell)$-approximate group.", "revisions": [ { "version": "v1", "updated": "2015-12-10T02:53:09.000Z" } ], "analyses": { "subjects": [ "11B13", "05A18", "11B75", "11P70", "20K99", "20M99", "52B20" ], "keywords": [ "asymptotic approximate group", "finite subset", "abelian group", "nonempty subset", "real vector space" ], "note": { "typesetting": "TeX", "pages": 14, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv151203130N" } } }