{ "id": "1611.00529", "version": "v1", "published": "2016-11-02T10:09:46.000Z", "updated": "2016-11-02T10:09:46.000Z", "title": "Packing Sets over Finite Fields", "authors": [ "Oliver Roche-Newton", "Arne Winterhof" ], "categories": [ "math.CO", "math.NT" ], "abstract": "For a given subset $A\\subseteq \\mathbb F_q^*$, we study the problem of finding a large packing set $B$ of $A$, that is, a set $B \\subseteq \\mathbb F_q^*$ such that $|AB|=|A||B|$. We prove the existence of such a $B$ of size $|B|\\ge (q-1)/|A/A|$ and show that this bound is in general optimal. The case that $q=p$ is a prime and $A=\\{1,2,\\ldots,\\lambda\\}$ for some positive integer $\\lambda$ is particularly interesting in view of the construction of limited-magnitude error correcting codes. Here we construct a packing set $B$ of size $|B|\\gg p (\\lambda \\log p)^{-1}$ for any $\\lambda \\le c p^{1/2}$ for some explicitly calcuable constant $c$. This result is optimal up to the logarithmic factor.", "revisions": [ { "version": "v1", "updated": "2016-11-02T10:09:46.000Z" } ], "analyses": { "subjects": [ "11B30", "11N69" ], "keywords": [ "finite fields", "limited-magnitude error correcting codes", "large packing set", "logarithmic factor", "general optimal" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }