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Related papers: Chern classes of Schubert cells and varieties

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The equivariant motivic Chern class of a Schubert cell in a `complete' flag manifold $X=G/B$ is an element in the equivariant K theory ring of $X$ to which one adjoins a formal parameter $y$. In this paper we prove several `folklore…

Algebraic Geometry · Mathematics 2025-04-02 Paolo Aluffi , Leonardo C. Mihalcea , Jörg Schürmann , Changjian Su

Let $X$ be a nonsingular complex projective variety and $D$ a locally quasi-homogeneous free divisor in $X$. In this paper we study a numerical relation between the Chern class of the sheaf of logarithmic derivations on $X$ with respect to…

Algebraic Geometry · Mathematics 2017-09-05 Xia Liao

We relate the geometry of Schubert varieties in twisted affine Grassmannian and the nilpotent varieties in symmetric spaces. This extends some results of Achar-Henderson in the twisted setting. We also get some applications to the geometry…

Representation Theory · Mathematics 2022-07-01 Jiuzu Hong , Korkeat Korkeathikhun

Let $L$ be a Levi subgroup of $GL_N$ which acts by left multiplication on a Schubert variety $X(w)$ in the Grassmannian $G_{d,N}$. We say that $X(w)$ is a spherical Schubert variety if $X(w)$ is a spherical variety for the action of $L$. In…

Representation Theory · Mathematics 2018-09-24 Reuven Hodges , Venkatramani Lakshmibai

We obtain several formulas for the Euclidean distance degree (ED degree) of an arbitrary nonsingular variety in projective space: in terms of Chern and Segre classes, Milnor classes, Chern-Schwartz-MacPherson classes, and an extremely…

Algebraic Geometry · Mathematics 2018-12-26 Paolo Aluffi , Corey Harris

Let V be a 2n-dimensional complex symplectic space. Let G' be the Lagrangian Grassmannian of maximal isotropic subspaces of V embedded via the inclusion i into the Grassmannian G of all n-dimensional subspaces of V. We discuss the…

Algebraic Geometry · Mathematics 2007-05-23 Piotr Pragacz

The Chern-Schwartz-MacPherson class (CSM) and the Segre-Schwartz-MacPherson class (SSM) are deformations of the fundamental class of an algebraic variety. They encode finer enumerative invariants of the variety than its fundamental class.…

Algebraic Geometry · Mathematics 2018-10-03 L. M. Feher , R. Rimanyi

In this work we study characteristic classes of possibly singular varieties embedded as a closed subvariety of a nonsingular variety. In special, we express the Schwartz-MacPherson class in terms of the $\mu$-class and Chern class of the…

Algebraic Geometry · Mathematics 2024-10-04 Antonio M. Ferreira , Fernando Lourenco

The Chern class of the sheaf of logarithmic derivations along a simple normal crossing divisor equals the Chern-Schwartz-MacPherson class of the complement of the divisor. We extend this equality to more general divisors, which are locally…

Algebraic Geometry · Mathematics 2013-03-04 Paolo Aluffi

A Schubert class is called rigid if it can only be represented by Schubert varieties. The rigid Schubert classes have been classified in Grassmannians and orthogonal Grassmannians. In this paper, we study the rigidity problem in partial…

Algebraic Geometry · Mathematics 2024-10-30 Yuxiang Liu , Artan Sheshmani , Shing-Tung Yau

In this paper, we introduce a family of symmetric polynomials by specializing the factorial Schur polynomials. These polynomials represent the weighted Schubert classes of the cohomology of the weighted Grassmannian introduced by…

Combinatorics · Mathematics 2015-02-02 Hiraku Abe , Tomoo Matsumura

The Euler characteristic of a very affine variety encodes the algebraic complexity of solving likelihood (or scattering) equations on this variety. We study this quantity for the Grassmannian with $d$ hyperplane sections removed. We provide…

Algebraic Geometry · Mathematics 2026-04-08 Elia Mazzucchelli , Dmitrii Pavlov , Kexin Wang

We establish a Gysin formula for Schubert bundles and a strong version of the duality theorem in Schubert calculus on Grassmann bundles. We then combine them to compute the fundamental classes of Schubert bundles in Grassmann bundles, which…

Algebraic Geometry · Mathematics 2020-09-03 Lionel Darondeau , Piotr Pragacz

Let G be a simply-connected simple compact Lie group over the complex numbers. The affine Grassmannian is a projective ind-variety, homotopy-equivalent to the loop space of G and closely analogous to a maximal flag variety of the classical…

Algebraic Geometry · Mathematics 2007-12-19 Sara C. Billey , Stephen A. Mitchell

This paper focuses on the properties of Schubert cells as quasi-projective subvarieties of a generalized flag variety. More specifically, we investigate the problem of distinguishing between different Schubert cells using vanishing patterns…

Combinatorics · Mathematics 2007-05-23 Sergey Fomin , Andrei Zelevinsky

In this paper a formula is proved for the general degeneracy locus associated to an oriented quiver of type A_n. Given a finite sequence of vector bundles with maps between them, these loci are described by putting rank conditions on…

Algebraic Geometry · Mathematics 2009-10-31 Anders S. Buch , William Fulton

We present two formulas for Chern classes of the tensor product of two vector bundles. In the first formula we consider a matrix containing Chern classes of the first bundle and we take a polynomial of this matrix with Chern classes of the…

Algebraic Topology · Mathematics 2019-10-01 Zsolt Szilágyi

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 give an elementary proof of the Pieri-type formula in the cohomology of a Grassmannian of maximal isotropic subspaces of an odd orthogonal or symplectic vector space. This proof proceeds by explicitly computing a triple intersection of…

alg-geom · Mathematics 2008-02-03 Frank Sottile

In this note, we discuss the flexibility of Schubert classes in homogeneous varieties. We give several constructions for representing multiples of a Schubert class by irreducible subvarieties. We sharpen [R, Theorem 3.1] by proving that…

Algebraic Geometry · Mathematics 2013-03-04 Izzet Coskun , Colleen Robles