Infinite flags and Schubert polynomials
Algebraic Geometry
2025-02-19 v2 Combinatorics
Abstract
We study Schubert polynomials using geometry of infinite-dimensional flag varieties and degeneracy loci. Applications include Graham-positivity of coefficients appearing in equivariant coproduct formulas and expansions of back-stable and enriched Schubert polynomials. We also construct an embedding of the type C flag variety, and study the corresponding pullback map on (equivariant) cohomology rings.
Cite
@article{arxiv.2105.11404,
title = {Infinite flags and Schubert polynomials},
author = {David Anderson},
journal= {arXiv preprint arXiv:2105.11404},
year = {2025}
}
Comments
40 pages, 2 figures. v2: omit Section 10 from v1, about affine flag varieties and Grassmannians (this material is superseded by arXiv:2305.19895); improved positivity statements and examples in Section 8; other minor changes and typo corrections