{ "id": "1511.03623", "version": "v1", "published": "2015-11-11T19:44:06.000Z", "updated": "2015-11-11T19:44:06.000Z", "title": "Inclusion Matrices and the MDS Conjecture", "authors": [ "Simeon Ball", "Ameera Chowdhury" ], "comment": "25 pages", "categories": [ "math.CO" ], "abstract": "Let F_q be a finite field of order q with characteristic p. An arc is an ordered family of vectors in (F_q)^k in which every subfamily of size k is a basis of (F_q)^k. The MDS conjecture, which was posed by Segre in 1955, states that if k <= q, then an arc in (F_q)^k has size at most q+1, unless q is even and k=3 or k=q-1, in which case it has size at most q+2. We propose a conjecture which would imply that the MDS conjecture is true for almost all values of k when q is odd. We prove our conjecture in two cases and thus give simpler proofs of the MDS conjecture when k <= p, and if q is not prime, for k <= 2p-2. To accomplish this, given an arc G of (F_q)^k and a nonnegative integer n, we construct a matrix M_G^{\\uparrow n}, which is related to an inclusion matrix, a well-studied object in combinatorics. Our main results relate algebraic properties of the matrix M_G^{\\uparrow n} to properties of the arc G and may provide new tools in the computational classification of large arcs.", "revisions": [ { "version": "v1", "updated": "2015-11-11T19:44:06.000Z" } ], "analyses": { "subjects": [ "15A03", "05B35", "51E21", "94B05" ], "keywords": [ "mds conjecture", "inclusion matrix", "main results relate algebraic properties", "finite field", "large arcs" ], "note": { "typesetting": "TeX", "pages": 25, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv151103623B" } } }