Equivariant Chern-Schwartz-MacPherson classes in partial flag varieties: interpolation and formulae

TL;DR

This paper establishes unique interpolation properties and explicit localization formulas for equivariant Chern-Schwartz-MacPherson classes of open Schubert varieties in partial flag manifolds, connecting them to quantum group actions.

Contribution

It proves that the equivariant Chern-Schwartz-MacPherson classes are uniquely determined by interpolation properties and provides explicit localization formulas, linking them to quantum group actions.

Findings

Unique determination of classes via interpolation properties

Explicit localization-type formulas for classes

Equivalence of Chern-Schwartz-MacPherson classes and quantum group classes

Abstract

Consider the natural torus action on a partial flag manifold $Fl$. Let $\Omega_I\subset Fl$ be an open Schubert variety, and let $c^{sm}(\Omega_I)\in H_T^*(Fl)$ be its torus equivariant Chern-Schwartz-MacPherson class. We show a set of interpolation properties that uniquely determine $c^{sm}(\Omega_I)$, as well as a formula, of `localization type', for $c^{sm}(\Omega_I)$. In fact, we proved similar results for a class $\kappa_I\in H_T^*(Fl)$ --- in the context of quantum group actions on the equivariant cohomology groups of partial flag varieties. In this note we show that $c^{SM}(\Omega_I)=\kappa_I$.