{ "id": "1312.1485", "version": "v2", "published": "2013-12-05T09:56:15.000Z", "updated": "2014-09-23T07:49:45.000Z", "title": "Subgroups of finite Abelian groups having rank two via Goursat's lemma", "authors": [ "László Tóth" ], "comment": "9 pages, revised, new results added, 1 figure, 1 table", "categories": [ "math.GR", "math.CO", "math.NT" ], "abstract": "Using Goursat's lemma for groups, a simple representation and the invariant factor decompositions of the subgroups of the group Z_m x Z_n are deduced, where m and n are arbitrary positive integers. As consequences, explicit formulas for the total number of subgroups, the number of subgroups with a given invariant factor decomposition, and the number of subgroups of a given order are obtained.", "revisions": [ { "version": "v1", "updated": "2013-12-05T09:56:15.000Z", "abstract": "Using Goursat's lemma for groups, a simple representation and the invariant factor decompositions of the subgroups of the group Z_m x Z_n is deduced, where m and n are arbitrary positive integers. As consequences, explicit formulas for the total number of subgroups, number of cyclic subgroups and the number of subgroups of a given order are obtained.", "comment": "7 pages, 1 figure", "journal": null, "doi": null }, { "version": "v2", "updated": "2014-09-23T07:49:45.000Z" } ], "analyses": { "subjects": [ "20K01", "20K27", "11A25" ], "keywords": [ "finite abelian groups", "goursats lemma", "invariant factor decompositions", "total number", "cyclic subgroups" ], "note": { "typesetting": "TeX", "pages": 9, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1312.1485T" } } }