{ "id": "1405.2603", "version": "v1", "published": "2014-05-11T23:55:52.000Z", "updated": "2014-05-11T23:55:52.000Z", "title": "A combinatorial proof that Schubert vs. Schur coefficients are nonnegative", "authors": [ "Sami Assaf", "Nantel Bergeron", "Frank Sottile" ], "comment": "26 pages, several colored figures", "categories": [ "math.CO" ], "abstract": "We give a combinatorial proof that the product of a Schubert polynomial by a Schur polynomial is a nonnegative sum of Schubert polynomials. Our proof uses Assaf's theory of dual equivalence to show that a quasisymmetric function of Bergeron and Sottile is Schur-positive. By a geometric comparison theorem of Buch and Mihalcea, this implies the nonnegativity of Gromov-Witten invariants of the Grassmannian.", "revisions": [ { "version": "v1", "updated": "2014-05-11T23:55:52.000Z" } ], "analyses": { "subjects": [ "05E05", "14M15" ], "keywords": [ "combinatorial proof", "schur coefficients", "schubert polynomial", "geometric comparison theorem", "dual equivalence" ], "note": { "typesetting": "TeX", "pages": 26, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1405.2603A" } } }