Equivariant Giambelli Formulae for Grassmannians

Abstract

In this thesis we use Young's raising operators to define and study polynomials which represent the Schubert classes in the equivariant cohomology ring of Grassmannians. For the type A and maximal isotropic Grassmannians, we show that our expressions coincide with the factorial Schur S, P, and Q functions. We define factorial theta polynomials, and conjecture that these represent the Schubert classes in the equivariant cohomology of non-maximal symplectic Grassmannians. We prove that the factorial theta polynomials satisfy the equivariant Chevalley formula, and that they agree with the type C double Schubert polynomials of [IMN] in some cases.