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Related papers: Deformed Cohomology of Flag Varieties

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In 2006, Belkale and Kumar define a new product on the cohomology of flag varieties and use this new product to give an improved solution to the eigencone problem for complex reductive groups. In this paper, we give a generalization of the…

Algebraic Geometry · Mathematics 2012-06-26 Nicolas Ressayre , Edward Richmond

We study the Belkale-Kumar family of cup products on the cohomology of a generalized flag variety. We give an alternative construction of the family using relative Lie algebra cohomology, and in particular, identify the Belkale-Kumar cup…

Algebraic Geometry · Mathematics 2011-05-30 Sam Evens , William Graham , with an appendix jointly written with Edward Richmond

Horn recursion is a term used to describe when non-vanishing products of Schubert classes in the cohomology of complex flag varieties are characterized by inequalities parameterized by similar non-vanishing products in the cohomology of…

Algebraic Geometry · Mathematics 2011-12-14 Edward Richmond

In this paper we prove some vanishing theorems for the twisted Dolbeault cohomology of the complete flag varieties associated to a simple, simply connected algebraic group.

Algebraic Geometry · Mathematics 2007-05-23 K Paramasamy

We study the local and global intersection cohomology of the intersection of two Schubert varieties in a flag manifold. In this version some new references are added.

Algebraic Geometry · Mathematics 2023-07-25 M. Dyer , G. Lusztig

We classify all products of flag varieties with finitely many orbits under the diagonal action of the general linear group. We also classify the orbits in each case and construct explicit representatives. This generalizes the classical…

Algebraic Geometry · Mathematics 2016-09-07 Peter Magyar , Jerzy Weyman , Andrei Zelevinsky

A unified approach to geometric, symbol and deformation quantizations on a generalized flag manifold endowed with an invariant pseudo-Kaehler structure is proposed. The Hilbert space of states is realized via the Bott-Borel-Weil theorem in…

dg-ga · Mathematics 2008-02-03 Alexander V. Karabegov

Consider the complete flag variety $X$ of a complex semisimple algebraic group $G$. We show that the structure coefficients of the Belkale-Kumar product $\odot_0$, on the cohomology $\mathrm{H}^{*}(X,\mathbf{Z})$, are all either $0$ or $1$.…

Algebraic Geometry · Mathematics 2025-03-28 Nicolas Ressayre , Luca Francone

Linear degenerate flag varieties are degenerations of flag varieties as quiver Grassmannians. For type A flag varieties, we obtain characterizations of flatness, irreducibility and normality of these degenerations via rank tuples. Some of…

Algebraic Geometry · Mathematics 2018-04-11 Giovanni Cerulli Irelli , Xin Fang , Evgeny Feigin , Ghislain Fourier , Markus Reineke

We use the formal affine Demazure algebra to construct an explicit Leray-Hirsch Theorem for torus equivariant oriented cohomology of flag varieties. We then generalize the Borel model of such theory to partial flag varieties.

Algebraic Geometry · Mathematics 2025-06-13 J. Matthew Douglass , Changlong Zhong

In the framework of the problem of characterizing complete flag manifolds by their contractions, the complete flags of type $F_4$ and $G_2$ satisfy the property that any possible tower of Bott-Samelson varieties dominating them birationally…

Algebraic Geometry · Mathematics 2022-02-24 Gianluca Occhetta , Luis E. Solá Conde

We extend the short presentation due to [Borel '53] of the cohomology ring of a generalized flag manifold to a relatively short presentation of the cohomology of any of its Schubert varieties. Our result is stated in a root-system uniform…

Combinatorics · Mathematics 2010-11-29 Victor Reiner , Alexander Woo , Alexander Yong

In this article, we give Maurer-Cartan characterizations of equivariant Lie superalgebra structures. We introduce equivariant cohomology and equivariant formal deformation theory of Lie superalgebras. As an application of equivariant…

General Mathematics · Mathematics 2023-01-04 RB Yadav , Subir Mukhopadhyay

Let G be a complex semi-simple Lie group and let P,Q be a pair of parabolic subgroups of G such that Q contains P. Consider the flag varieties G/P, G/Q and Q/P. We show that certain structure constants in H^*(G/P) with respect to the…

Algebraic Geometry · Mathematics 2012-06-26 Edward Richmond

Let $G$ be a simple, simply-connected complex algebraic group with Lie algebra $\mathfrak{g}$, and $G/B$ the associated complete flag variety. The Hochschild cohomology $HH^\bullet(G/B)$ is a geometric invariant of the flag variety related…

Representation Theory · Mathematics 2025-01-17 Sam Jeralds

We prove a short, root-system uniform, combinatorial classification of Levi-spherical Schubert varieties for any generalized flag variety $G/B$ of finite Lie type. We apply this to the study of multiplicity-free decompositions of a Demazure…

Representation Theory · Mathematics 2024-03-25 Yibo Gao , Reuven Hodges , Alexander Yong

We introduce a new cohomology theory related to deformations of Lie algebra morphisms. This notion involves simultaneous deformations of two Lie algebras and a homomorphism between them.

Quantum Algebra · Mathematics 2007-05-23 Yael Fregier

We establish the deformation theory of Lie groupoid morphisms, describe the corresponding deformation cohomology of morphisms, and show the properties of the cohomology. We prove its invariance under isomorphisms of morphisms. Additionally,…

Differential Geometry · Mathematics 2023-12-21 Cristian Camilo Cárdenas

We describe a construction of Gromov-Witten invariants for flag varieties and use it to give a presentation for the quantum cohomology ring, by extending the ideas used by Bertram in the case of Grassmannians. This provides a proof for the…

alg-geom · Mathematics 2008-02-03 Ionuţ Ciocan-Fontanine

We consider closed subschemes in the affine grassmannian obtained by degenerating $e$-fold products of flag varieties, embedded via a tuple of dominant cocharacters. For $G= \operatorname{GL}_2$, and cocharacters small relative to the…

Number Theory · Mathematics 2023-05-10 Robin Bartlett
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