English
Related papers

Related papers: Generalized permutahedra and Schubert calculus

200 papers

We give a combinatorial rule for computing intersection numbers on a flag manifold which come from products of Schubert classes pulled back from Grassmannian projections. This rule generalizes the known rule for Grassmannians.

Combinatorics · Mathematics 2008-05-03 Kevin Purbhoo , Frank Sottile

In this paper, a description of the set-theoretical defining equations of symplectic (type C) Grassmannian/flag/Schubert varieties in corresponding (type A) algebraic varieties is given as linear polynomials in Pl$\ddot{u}$cker coordinates,…

Algebraic Geometry · Mathematics 2023-04-21 Jiajun Xu , Guanglian Zhang

We previously obtained a congruence modulo four for the number of real solutions to many Schubert problems on a square Grassmannian given by osculating flags. Here, we consider Schubert problems given by more general isotropic flags, and…

Algebraic Geometry · Mathematics 2015-02-06 Nickolas Hein , Frank Sottile , Igor Zelenko

In this note, we give Gysin formulas for partial flag bundles for the classical groups. We then give Gysin formulas for Schubert varieties in Grassmann bundles, including isotropic ones. All these formulas are proved in a rather uniform way…

Algebraic Geometry · Mathematics 2018-02-27 Lionel Darondeau , Piotr Pragacz

We construct a canonical isomorphism between the Bethe algebra acting on a multiplicity space of a tensor product of evaluation gl_N[t]-modules and the scheme-theoretic intersection of suitable Schubert varieties. Moreover, we prove that…

Quantum Algebra · Mathematics 2007-11-27 E. Mukhin , V. Tarasov , A. Varchenko

The Shapiro conjecture in the real Schubert calculus fails to hold for flag manifolds, but in a very interesting way. In this extended abstract, we give a refinement of that conjecture for the flag manifold and present massive…

Algebraic Geometry · Mathematics 2007-05-23 James Ruffo , Yuval Sivan , Evgenia Soprunova , Frank Sottile

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

Hilbert's 15th problem called for a rigorous foundation of Schubert's calculus, in which a long standing and challenging part is Schubert's problem of characteristics. In the course of securing the foundation of algebraic geometry, Van der…

Algebraic Geometry · Mathematics 2023-02-10 Haibao Duan , Xuezhi Zhao

We show that various genus zero Gromov-Witten invariants for flag varieties representing different homology classes are indeed the same. In particular, many of them are classical intersection numbers of Schubert cycles.

Algebraic Geometry · Mathematics 2011-07-26 Naichung Conan Leung , Changzheng Li

We introduce and study a new mathematical structure in the generalised (quantum) cohomology theory for Grassmannians. Namely, we relate the Schubert calculus to a quantum integrable system known in the physics literature as the asymmetric…

Representation Theory · Mathematics 2017-05-24 Vassily Gorbounov , Christian Korff

We describe a Schubert induction theorem, a tool for analyzing intersections on a Grassmannian over an arbitrary base ring. The key ingredient in the proof is the Geometric Littlewood-Richardson rule, described in a companion paper.…

Algebraic Geometry · Mathematics 2007-05-23 Ravi Vakil

Let $G/P$ be a complex cominuscule flag manifold. We prove a type independent formula for the torus equivariant Mather class of a Schubert variety in $G/P$, and for a Schubert variety pulled back via the natural projection $G/Q \to G/P$. We…

Algebraic Geometry · Mathematics 2020-06-11 Leonardo C. Mihalcea , Rahul Singh

Points in the intersection of Schubert varieties are counted by various combinatorial objects, for example standard tableaux. This paper consider the problem of producing a natural labelling of intersection points by these combinatorial…

Representation Theory · Mathematics 2019-12-24 Noah White

We develop numerical homotopy algorithms for solving systems of polynomial equations arising from the classical Schubert calculus. These homotopies are optimal in that generically no paths diverge. For problems defined by hypersurface…

alg-geom · Mathematics 2025-10-20 Birkett Huber , Frank Sottile , Bernd Sturmfels

An important combinatorial result in equivariant cohomology and $K$-theory Schubert calculus is represented by the formulas of Billey and Graham-Willems for the localization of Schubert classes at torus fixed points. These formulas work…

Algebraic Geometry · Mathematics 2017-11-01 Cristian Lenart , Kirill Zainoulline

The goal of the paper is two-fold. At first, we attempt to give a survey of some recent applications of symmetric polynomials and divided differences to intersection theory. We discuss: polynomials universally supported on degeneracy loci;…

alg-geom · Mathematics 2008-02-03 Piotr Pragacz

The quantum double Schubert polynomials studied by Kirillov and Maeno, and by Ciocan-Fontanine and Fulton, are shown to represent Schubert classes in Kim's presentation of the equivariant quantum cohomology of the flag variety. We define…

Combinatorics · Mathematics 2011-08-26 Thomas Lam , Mark Shimozono

We give an algorithm to compute the integer cohomology groups of any real partial flag manifold, by computing the incidence coefficients of the Schubert cells. For even flag manifolds we determine the integer cohomology groups, by proving…

Geometric Topology · Mathematics 2019-10-25 Ákos K. Matszangosz

Let $\mathbf{G}$ be one of the ind-groups $GL(\infty)$, $O(\infty)$, $Sp(\infty)$ and $\mathbf{P}\subset \mathbf{G}$ be a splitting parabolic ind-subgroup. The ind-variety $\mathbf{G}/\mathbf{P}$ has been identified with an ind-variety of…

Representation Theory · Mathematics 2015-06-30 Lucas Fresse , Ivan Penkov

In this article, the comodule structure of Chow rings of Flag manifolds $\operatorname{CH}(G/B)$ is described by Schubert cells. Its equivariant version gives rise to a Hopf structure of the equivariant cohomology of flag manifolds…

Representation Theory · Mathematics 2020-10-30 Rui Xiong