Results 31 to 40 of about 1,037 (65)

Δ–Springer varieties and Hall–Littlewood polynomials

Forum of Mathematics, Sigma
The $\Delta $ -Springer varieties are a generalization of Springer fibers introduced by Levinson, Woo and the author that have connections to the Delta Conjecture from algebraic combinatorics.
Sean T. Griffin
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Coordinate rings of regular nilpotent Hessenberg varieties in the open opposite schubert cell

Forum of Mathematics, Sigma
Dale Peterson has discovered a surprising result that the quantum cohomology ring of the flag variety $\operatorname {\mathrm {GL}}_n({\mathbb {C}})/B$ is isomorphic to the coordinate ring of the intersection of the Peterson variety ...
Tatsuya Horiguchi, Tomoaki Shirato
doaj   +1 more source

Geometrization of the Satake transform for mod p Hecke algebras

Forum of Mathematics, Sigma
We geometrize the mod p Satake isomorphism of Herzig and Henniart–Vignéras using Witt vector affine flag varieties for reductive groups in mixed characteristic. We deduce this as a special case of a formula, stated in terms of the geometry of generalized
Robert Cass, Yujie Xu
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K-Orbit closures and Hessenberg varieties

Forum of Mathematics, Sigma
This article explores the relationship between Hessenberg varieties associated with semisimple operators with two eigenvalues and orbit closures of a spherical subgroup of the general linear group.
Mahir Bilen Can, Martha Precup, John Shareshian, Özlem Uğurlu   +3 more
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Combinatorial formulas for shifted dual stable Grothendieck polynomials

Forum of Mathematics, Sigma
The K-theoretic Schur P- and Q-functions $G\hspace {-0.2mm}P_\lambda $ and $G\hspace {-0.2mm}Q_\lambda $ may be concretely defined as weight-generating functions for semistandard shifted set-valued tableaux.
Joel Lewis, Eric Marberg
doaj   +1 more source

On the K-theoretic fundamental classes of Deligne-Lusztig varieties

, 2020
In this paper we express the class of the structure sheaves of the closures of Deligne--Lusztig varieties as explicit double Grothendieck polynomials in the first Chern classes of appropriate line bundles on the ambient flag variety.
Hudson, Thomas, Peters, Dennis
core  

An inverse Grassmannian Littlewood–Richardson rule and extensions

Forum of Mathematics, Sigma
Chow rings of flag varieties have bases of Schubert cycles $\sigma _u $ , indexed by permutations. A major problem of algebraic combinatorics is to give a positive combinatorial formula for the structure constants of this basis.
Oliver Pechenik, Anna Weigandt
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Smooth locus of twisted affine Schubert varieties and twisted affine Demazure modules

Forum of Mathematics, Sigma
Let ${\mathscr {G}} $ be a special parahoric group scheme of twisted type over the ring of formal power series over $\mathbb {C}$ , excluding the absolutely special case of $A^{(2)}_{2\ell }$ .
Marc Besson, Jiuzu Hong
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Quantum K theory of Grassmannians, Wilson line operators and Schur bundles

Forum of Mathematics, Sigma
We prove a ‘Whitney’ presentation, and a ‘Coulomb branch’ presentation, for the torus equivariant quantum K theory of the Grassmann manifold $\mathrm {Gr}(k;n)$ , inspired from physics, and stated in an earlier paper.
Wei Gu, Leonardo Mihalcea, Eric Sharpe, Hao Zou   +3 more
doaj   +1 more source

A categorical action of the shifted $0$ -affine algebra

Forum of Mathematics, Sigma
We introduce a new algebra $\mathcal {U}=\dot {\mathrm {\mathbf{U}}}_{0,N}(L\mathfrak {sl}_n)$ called the shifted $0$ -affine algebra, which emerges naturally from studying coherent sheaves on n-step partial flag varieties through natural ...
You-Hung Hsu
doaj   +1 more source