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Related papers: A Chevalley formula in equivariant $K$-theory

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We address a unification of the Schubert calculus problems solved by [A. Buch '02] and [A. Knutson-T. Tao '03]. That is, we prove a combinatorial rule for the structure coefficients in the torus-equivariant K-theory of Grassmannians with…

Combinatorics · Mathematics 2017-07-11 Oliver Pechenik , Alexander Yong

In a recent paper, we stated conjectural presentations for the equivariant quantum K ring of partial flag varieties, motivated by physics considerations. In this companion paper, we analyze these presentations mathematically. We start by…

Algebraic Geometry · Mathematics 2024-11-18 Wei Gu , Leonardo C. Mihalcea , Eric Sharpe , Weihong Xu , Hao Zhang , Hao Zou

The aim of this paper is to describe the topological $K$-ring, in terms of generators and relations of a flag Bott manifold. We apply our results to give a presentation for the topological K-ring and hence the Grothendieck ring of algebraic…

Algebraic Topology · Mathematics 2026-01-15 Bidhan Paul , Vikraman Uma

In this paper, using the quantum McKay correspondence, we construct the "derived category" of G-equivariant sheaves on the quantum projective line at a root of unity. More precisely, we use the representation theory of U_{q}sl(2) at root of…

Representation Theory · Mathematics 2012-10-18 Alexander Kirillov , Jaimal Thind

We explain that the Pontryagin product structure on the equivariant $K$-group of an affine Grassmannian considered in [Lam-Schilling-Shimozono, Compos. Math. {\bf 146} (2010)] coincides with the tensor structure on the equivariant $K$-group…

Algebraic Geometry · Mathematics 2024-12-30 Syu Kato

We define skew Schubert polynomials to be normal form (polynomial) representatives of certain classes in the cohomology of a flag manifold. We show that this definition extends a recent construction of Schubert polynomials due to Bergeron…

Combinatorics · Mathematics 2010-03-29 Cristian Lenart , Frank Sottile

We use the construction of the stable homotopy category by Khan-Ravi to calculate the integral $T$-equivariant $K$-theory spectrum of a flag variety over an affine scheme, where $T$ is a split torus associated to the flag variety. More…

Algebraic Geometry · Mathematics 2025-08-20 Can Yaylali

Fomin and Kirillov initiated a line of research into the realization of the cohomology and $K$-theory of generalized flag varieties $G/B$ as commutative subalgebras of certain noncommutative algebras. This approach has several advantages,…

Quantum Algebra · Mathematics 2007-05-23 Cristian Lenart , Toshiaki Maeno

Tangent spaces to Schubert varieties of type A were characterized by Lakshmibai and Seshadri. This result was extended to the other classical types by Lakshmibai. We give a uniform characterization of tangent spaces to Schubert varieties in…

Algebraic Geometry · Mathematics 2022-02-23 William Graham , Victor Kreiman

We interpret certain equivariant Kasparov groups as equivariant representable K-theory groups. We compute these groups via a classifying space and as K-theory groups of suitable sigma-C*-algebras. We also relate equivariant vector bundles…

K-Theory and Homology · Mathematics 2015-10-23 Heath Emerson , Ralf Meyer

A Laurent polynomial ring $A[t,1/t]$ with coefficients in a unital ring $A$ determines a category of quasi-coherent sheaves on the projective line over $A$; its $K$-theory is known to split into a direct sum of two copies of the $K$-theory…

K-Theory and Homology · Mathematics 2026-05-21 Thomas Huettemann , Tasha Montgomery

We use group homology to define invariants in algebraic K-theory and in an analogue of the Bloch group for Q-rank one lattices and for some other geometric structures. We also show that the Bloch invariants of CR structures and of flag…

Geometric Topology · Mathematics 2012-10-29 Inkang Kim , Sungwoon Kim , Thilo Kuessner

Using the description of the category of quasi-coherent sheaves on a root stack given in the paper of N. Borne and A. Vistoli, we study the G-theory of root stacks via localisation methods. We apply our results to the study of equivariant…

Algebraic Geometry · Mathematics 2019-08-14 A. Dhillon , I. Kobyzev

Consider a flag variety $Fl$ over an algebraically closed field, and a subvariety $V$ whose cycle class is a multiplicity-free sum of Schubert cycles. We show that $V$ is arithmetically normal and Cohen-Macaulay, in the projective embedding…

Algebraic Geometry · Mathematics 2007-05-23 Michel Brion

Building on the theory of parity sheaves due to Juteau-Mautner-Williamson, we develop a formalism of "mixed modular perverse sheaves" for varieties equipped with a stratification by affine spaces. We then give two applications: (1) a…

Representation Theory · Mathematics 2016-02-10 Pramod N. Achar , Simon Riche

We prove a conjecture of A. S. Buch concerning the structure constants of the Grothendieck ring of a flag variety with respect to its basis of Schubert structure sheaves. For this, we show that the coefficients in this basis of the…

Algebraic Geometry · Mathematics 2007-05-23 Michel Brion

Peterson varieties are a special class of Hessenberg varieties that have been extensively studied e.g. by Peterson, Kostant, and Rietsch, in connection with the quantum cohomology of the flag variety. In this manuscript, we develop a…

Algebraic Geometry · Mathematics 2014-02-26 Megumi Harada , Julianna Tymoczko

We apply the technique of formal geometry to give a necessary and sufficient condition for a line bundle supported on a smooth Lagrangian subvariety to deform to a sheaf of modules over a fixed deformation quantization of the structure…

Algebraic Geometry · Mathematics 2015-02-19 Vladimir Baranovsky , Victor Ginzburg , Dmitry Kaledin , Jeremy Pecharich

We compare two notions of $G$-fiber bundles and $G$-principal bundles in the literature, with an aim to clarify early results in equivariant bundle theory that are needed in current work of equivariant algebraic topology. We also give…

Algebraic Topology · Mathematics 2021-06-22 Foling Zou

Following Hopkins and Singer, we give a definition for the differential equivariant K-theory of a smooth manifold acted upon by a finite group. The ring structure for differential equivariant K-theory is developed explicitly. We also…

Algebraic Topology · Mathematics 2009-06-01 Michael L. Ortiz