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In previous work we equipped quiver Grassmannians for nilpotent representations of the equioriented cycle with an action of an algebraic torus. We show here that the equivariant cohomology ring is acted upon by a product of symmetric groups…

Representation Theory · Mathematics 2021-05-24 Martina Lanini , Alexander Pütz

We define and investigate algebraic torus actions on quiver Grassmannians for nilpotent representations of the equioriented cycle. Examples of such varieties are type $\tt A$ flag varieties, their linear degenerations, finite dimensional…

Representation Theory · Mathematics 2023-01-03 Martina Lanini , Alexander Pütz

Recent work of Chen He has determined through GKM methods the Borel equivariant cohomology with rational coefficients of the isotropy action on a real Grassmannian and an real oriented Grassmannian through GKM methods. In this expository…

Algebraic Topology · Mathematics 2023-11-28 Jeffrey D. Carlson

Given an equivariant oriented cohomology theory $h$, a split reductive group $G$, a maximal torus $T$ in $G$, and a parabolic subgroup $P$ containing $T$, we explain how the $T$-equivariant oriented cohomology ring $h_T(G/P)$ can be…

Algebraic Geometry · Mathematics 2015-11-12 Baptiste Calmès , Kirill Zainoulline , Changlong Zhong

This paper introduces a two-parameter deformation of the cohomology of generalized flag varieties. One special case is the Belkale-Kumar deformation (used to study eigencones of Lie groups). Another picks out intersections of Schubert…

Algebraic Geometry · Mathematics 2018-07-12 Oliver Pechenik , Dominic Searles

Let G be a complex semisimple linear algebraic group and let Pet be the associated Peterson variety in the flag variety G/B. The main theorem of this note gives an efficient presentation of the equivariant cohomology ring H^*_S(Pet) of the…

Algebraic Geometry · Mathematics 2019-08-15 Megumi Harada , Tatsuya Horiguchi , Mikiya Masuda

We prove a Pieri-Chevalley formula for anti-dominant weights and also a Monk formula in the torus-equivariant $K$-group of the formal power series model of semi-infinite flag manifolds, both of which are described explicitly in terms of…

Quantum Algebra · Mathematics 2020-03-17 Satoshi Naito , Daniel Orr , Daisuke Sagaki

Noncommutative K\"ahler structures were recently introduced by the second author as a framework for studying noncommutative K\"ahler geometry on quantum homogeneous spaces. It was subsequently observed that the notion of a positive vector…

Quantum Algebra · Mathematics 2022-12-13 Fredy Díaz García , Andrey Krutov , Réamonn Ó Buachalla , Petr Somberg , Karen R. Strung

In this paper, we give an explicit formula of Chevalley type, in terms of the Bruhat graph, for the quantum multiplication with the class of the line bundle associated to the anti-dominant minuscule fundamental weight $- \varpi_{k}$ in the…

Quantum Algebra · Mathematics 2020-05-05 Takafumi Kouno , Satoshi Naito , Daisuke Sagaki

Based on the Basis theorem of Bruhat--Chevalley [C] and the formula for multiplying Schubert classes obtained in [D\QTR{group}{u}] and programed in [DZ$_{\QTR{group}{1}}$], we introduce a new method computing the Chow rings of flag…

Algebraic Geometry · Mathematics 2014-01-14 Haibao Duan , Xuezhi Zhao

In this paper, we give a new generalization of positive sectional curvature called positive weighted sectional curvature. It depends on a choice of Riemannian metric and a smooth vector field. We give several simple examples of Riemannian…

Differential Geometry · Mathematics 2014-10-08 Lee Kennard , William Wylie

In this paper, we establish equivariant mirror symmetry for the weighted projective line. This extends the results by B. Fang, C.C. Liu and Z. Zong, where the projective line was considered [{\it Geometry \& Topology} 24:2049-2092, 2017].…

Algebraic Geometry · Mathematics 2018-08-10 Dun Tang

We describe the integral equivariant cohomology ring of a weighted projective space in terms of piecewise polynomials, and thence by generators and relations. We deduce that the ring is a perfect invariant, and prove a Chern class formula…

Algebraic Topology · Mathematics 2009-04-15 Anthony Bahri , Matthias Franz , Nigel Ray

We determine the ring structure of the torus-equivariant cohomology of rank-one juggling varieties with rational coefficients. By realizing these varieties as cyclic quiver Grassmannians, we construct a Knutson--Tao type basis for their…

Algebraic Geometry · Mathematics 2026-04-14 Bidhan Paul

M. Goresky, G. Harder, and R. MacPherson defined weighted cohomologies of arithmetic groups \Gamma in a real group G, with coefficients in certain local systems, associated to arbitrary upper and lower weight profiles. The author shows,…

Number Theory · Mathematics 2016-09-07 Arvind Nair

Explicit combinatorial cancellation-free rules are given for the product of an equivariant line bundle class with a Schubert class in the torus-equivariant K-theory of a Kac-Moody flag manifold. The weight of the line bundle may be dominant…

Combinatorics · Mathematics 2012-03-16 Cristian Lenart , Mark Shimozono

For a variety with a Whitney stratification by affine spaces, we study categories of motivic sheaves which are constant mixed Tate along the strata. We are particularly interested in those cases where the category of mixed Tate motives over…

Representation Theory · Mathematics 2016-03-02 Wolfgang Soergel , Matthias Wendt

We show that the dualizing sheaves of reduced simple normal crossings pairs have a canonical weight filtration in a compatible way with the one on the corresponding mixed Hodge modules by calculating the extension classes between the…

Algebraic Geometry · Mathematics 2013-06-25 Osamu Fujino , Taro Fujisawa , Morihiko Saito

We prove that Schubert and Richardson varieties in flag manifolds are uniquely determined by their equivariant cohomology classes, as well as a stronger result that replaces Schubert varieties with closures of Bialynicki-Birula cells under…

Algebraic Geometry · Mathematics 2025-08-27 Anders S. Buch , Pierre-Emmanuel Chaput , Nicolas Perrin

The rim-hook rule for quantum cohomology of the Grassmannian allows one to reduce quantum calculations to classical calculations in the cohomology of the Grassmannian. We use the Abelian/non-Abelian correspondence for cohomology to prove a…

Algebraic Geometry · Mathematics 2020-09-08 Wei Gu , Elana Kalashnikov