{ "id": "1104.2519", "version": "v2", "published": "2011-04-13T14:51:29.000Z", "updated": "2012-02-15T02:10:43.000Z", "title": "Log-concavity of characteristic polynomials and the Bergman fan of matroids", "authors": [ "June Huh", "Eric Katz" ], "comment": "12 pages", "categories": [ "math.CO", "math.AG" ], "abstract": "In a recent paper, the first author proved the log-concavity of the coefficients of the characteristic polynomial of a matroid realizable over a field of characteristic 0, answering a long-standing conjecture of Read in graph theory. We extend the proof to all realizable matroids, making progress towards a more general conjecture of Rota-Heron-Welsh. Our proof follows from an identification of the coefficients of the reduced characteristic polynomial as answers to particular intersection problems on a toric variety. The log-concavity then follows from an inequality of Hodge type.", "revisions": [ { "version": "v2", "updated": "2012-02-15T02:10:43.000Z" } ], "analyses": { "keywords": [ "bergman fan", "log-concavity", "intersection problems", "coefficients", "hodge type" ], "note": { "typesetting": "TeX", "pages": 12, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011arXiv1104.2519H" } } }