%0 Journal Article
%T A combinatorial proof that Schubert vs. Schur coefficients are nonnegative
%A Sami Assaf
%A Nantel Bergeron
%A Frank Sottile
%J Mathematics
%D 2014
%I arXiv
%X 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.
%U http://arxiv.org/abs/1405.2603v1