On the coproduct in affine Schubert calculus
Combinatorics
2020-09-22 v2 Algebraic Geometry
Abstract
The cohomology of the affine flag variety of a complex reductive group is a comodule over the cohomology of the affine Grassmannian. We give positive formulae for the coproduct of an affine Schubert class in terms of affine Stanley classes and finite Schubert classes, in (torus-equivariant) cohomology and K-theory. As an application, we deduce monomial positivity for the affine Schubert polynomials of the second author.
Cite
@article{arxiv.1906.08118,
title = {On the coproduct in affine Schubert calculus},
author = {Thomas Lam and Seung Jin Lee and Mark Shimozono},
journal= {arXiv preprint arXiv:1906.08118},
year = {2020}
}
Comments
25 pages