{ "id": "1111.5216", "version": "v2", "published": "2011-11-22T15:15:19.000Z", "updated": "2012-09-08T13:01:47.000Z", "title": "Characterization of cyclic Schur groups", "authors": [ "Sergei Evdokimov", "István Kovács", "Ilya Ponomarenko" ], "comment": "the second version; the proof was substantially improved; 29 pages", "categories": [ "math.CO" ], "abstract": "A finite group $G$ is called a Schur group, if any Schur ring over $G$ is the transitivity module of a permutation group on the set $G$ containing the regular subgroup of all right translations. It was proved by R. P\\\"oschel (1974) that given a prime $p\\ge 5$ a $p$-group is Schur if and only if it is cyclic. We prove that a cyclic group of order $n$ is a Schur group if and only if $n$ belongs to one of the following five (partially overlapped) families of integers: $p^k$, $pq^k$, $2pq^k$, $pqr$, $2pqr$ where $p,q,r$ are distinct primes, and $k\\ge 0$ is an integer.", "revisions": [ { "version": "v2", "updated": "2012-09-08T13:01:47.000Z" } ], "analyses": { "subjects": [ "05E30", "20B25" ], "keywords": [ "cyclic schur groups", "characterization", "distinct primes", "cyclic group", "transitivity module" ], "note": { "typesetting": "TeX", "pages": 29, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011arXiv1111.5216E" } } }