Schubert varieties in the Grassmannian and the symplectic Grassmannian via a bounded RSK correspondence

摘要

Abstract In a paper by Kodiyalam and Raghavan, they provide an explicit combinatorial description of the Hilbert function of the tangent cone at any point on a Schubert variety in the Grassmannian, by giving a certain “degree-preserving” bijection between a set of monomials defined by an initial ideal and a “standard monomial basis”. We prove here that this bijection is in fact a bounded RSK correspondence. As an application, we prove that the bijection given in a paper of Ghorpade and Raghavan (for the symplectic Grassmannian) is also a bounded RSK correspondence.