{ "id": "1611.06546", "version": "v1", "published": "2016-11-20T17:04:03.000Z", "updated": "2016-11-20T17:04:03.000Z", "title": "A characterisation of elementary abelian 3-groups", "authors": [ "Chimere Anabanti" ], "categories": [ "math.CO" ], "abstract": "Tarnauceanu [Archiv der Mathematik, 102 (1), (2014), 11--14] gave a characterisation of elementary abelian $2$-groups in terms of their maximal sum-free sets. His theorem states that a finite group $G$ is an elementary abelian $2$-group if and only if the set of maximal sum-free sets coincides with the set of complements of the maximal subgroups. A corollary is that the number of maximal sum-free sets in an elementary abelian $2$-group of finite rank $n$ is $2^n-1$. Regretfully, we show here that the theorem is wrong. We then prove a correct version of the theorem from which the desired corollary can be deduced. Moreover, we give a characterisation of elementary abelian $3$-groups in terms of their maximal sum-free sets. A corollary to our result is that the number of maximal sum-free sets in an elementary abelian $3$-group of finite rank $n$ is $3^n-1$. Finally, for prime $p>3$ and $n\\in \\mathbb{N}$, we show that there is no direct analogue of this result for elementary abelian $p$-groups of finite rank $n$.", "revisions": [ { "version": "v1", "updated": "2016-11-20T17:04:03.000Z" } ], "analyses": { "subjects": [ "11B75", "20D60", "20K01", "05E15" ], "keywords": [ "elementary abelian", "finite rank", "characterisation", "maximal sum-free sets coincides", "archiv der mathematik" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }