{ "id": "1106.2944", "version": "v4", "published": "2011-06-15T11:35:58.000Z", "updated": "2013-06-10T16:56:57.000Z", "title": "Matroids and log-concavity", "authors": [ "Matthias Lenz" ], "comment": "9 pages", "categories": [ "math.CO", "cs.DM" ], "abstract": "We show that f-vectors of matroid complexes of realisable matroids are log-concave. This was conjectured by Mason in 1972. Our proof uses the recent result by Huh and Katz who showed that the coefficients of the characteristic polynomial of a realisable matroid form a log-concave sequence. We also discuss the relationship between log-concavity of f-vectors and h-vectors of matroids. In the last section we explain the connection between zonotopal algebra and f-vectors and characteristic polynomials of matroids.", "revisions": [ { "version": "v4", "updated": "2013-06-10T16:56:57.000Z" } ], "analyses": { "subjects": [ "05A20", "05B35", "05E45", "05C31" ], "keywords": [ "log-concavity", "characteristic polynomial", "log-concave sequence", "realisable matroid form", "matroid complexes" ], "note": { "typesetting": "TeX", "pages": 9, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011arXiv1106.2944L" } } }