{ "id": "1508.05524", "version": "v1", "published": "2015-08-22T16:37:19.000Z", "updated": "2015-08-22T16:37:19.000Z", "title": "Sets with few differences in abelian groups", "authors": [ "Mitchell Lee" ], "comment": "21 pages, 1 figure", "categories": [ "math.CO" ], "abstract": "Let $(G, +)$ be an abelian group. In 2004, Eliahou and Kervaire found an explicit formula for the smallest possible cardinality of the sumset $A+A$, where $A \\subseteq G$ has fixed cardinality $r$. We consider instead the smallest possible cardinality of the difference set $A-A$, which is always greater than or equal to the smallest possible cardinality of $A+A$ and can be strictly greater. We conjecture a formula for this quantity, and prove the conjecture in the case that $G$ is a cyclic group or a vector space over a finite field. This resolves a conjecture of Bajnok and Matzke on signed sumsets.", "revisions": [ { "version": "v1", "updated": "2015-08-22T16:37:19.000Z" } ], "analyses": { "keywords": [ "abelian group", "conjecture", "finite field", "explicit formula", "cyclic group" ], "note": { "typesetting": "TeX", "pages": 21, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv150805524L" } } }