Abstracts for AMS Special Session
Ring Structures in the Schubert Calculus
The quantum Bruhat graph, which is an extension of the graph formed by covering relations in the Bruhat order, is naturally related to the quantum cohomology ring of G/B. We enhance a result of Fulton and Woodward by showing that the minimal monomial in the quantum parameters that occurs in the quantum product of two Schubert classes has a simple interpretation in terms of directed paths in this graph.
We define path Schubert polynomials, which are quantum cohomology analogues
of skew Schubert polynomials recently introduced by Lenart and Sottile.
They are given by sums over paths in the quantum Bruhat graph of type A.
The 3-point Gromov-Witten invariants for the flag manifold are expressed
in terms of these polynomials. This construction gives a combinatorial
description for the set of all monomials in the quantum parameters that
occur in the quantum product of two Schubert classes.
Back Organizers: Frank Sottile & Chris Woodward