Combinatorial description of the cohomology of the affine flag variety

We construct the affine version of the Fomin-Kirillov algebra, called the affine FK algebra, to investigatethe combinatorics of affine Schubert calculus for typeA. We introduce Murnaghan-Nakayama elements and Dunklelements in the affine FK algebra. We show that they are commutative as Bruhat operato...

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Bibliographic Details
Published in:Discrete mathematics and theoretical computer science Vol. DMTCS Proceedings, 28th...
Main Author: Lee, Seung Jin
Format: Journal Article Conference Proceeding
Language:English
Published: DMTCS 22.04.2020
Discrete Mathematics & Theoretical Computer Science
Subjects:
ISSN:1365-8050, 1462-7264, 1365-8050
Online Access:Get full text
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Summary:We construct the affine version of the Fomin-Kirillov algebra, called the affine FK algebra, to investigatethe combinatorics of affine Schubert calculus for typeA. We introduce Murnaghan-Nakayama elements and Dunklelements in the affine FK algebra. We show that they are commutative as Bruhat operators, and the commutativealgebra generated by these operators is isomorphic to the cohomology of the affine flag variety. As a byproduct, weobtain Murnaghan-Nakayama rules both for the affine Schubert polynomials and affine Stanley symmetric functions. This enable us to expressk-Schur functions in terms of power sum symmetric functions. We also provide the defi-nition of the affine Schubert polynomials, polynomial representatives of the Schubert basis in the cohomology of theaffine flag variety.
ISSN:1365-8050
1462-7264
1365-8050
DOI:10.46298/dmtcs.6326