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Related papers: Schubert curves in the orthogonal Grassmannian

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We establish a combinatorial connection between the real geometry and the $K$-theory of complex Schubert curves $S(\lambda_\bullet)$, which are one-dimensional Schubert problems defined with respect to flags osculating the rational normal…

Combinatorics · Mathematics 2016-09-13 Maria Monks Gillespie , Jake Levinson

We establish a combinatorial connection between the real geometry and the $K$-theory of complex Schubert curves $S(\lambda_\bullet)$, which are one-dimensional Schubert problems defined with respect to flags osculating the rational normal…

Combinatorics · Mathematics 2015-12-22 Maria Monks Gillespie , Jake Levinson

We consider Schubert problems with respect to flags osculating the rational normal curve. These problems are of special interest when the osculation points are all real -- in this case, for zero-dimensional Schubert problems, the solutions…

Algebraic Geometry · Mathematics 2019-08-15 Jake Levinson

We obtain a combinatorial expression for the coefficients of the boundary map of real isotropic and odd orthogonal Grassmannians providing a natural generalization of the formulas already obtained for Lagrangian and maximal isotropic…

Algebraic Topology · Mathematics 2023-03-10 Jordan Lambert , Lonardo Rabelo

We propose a theory of combinatorially explicit Schubert polynomials which represent the Schubert classes in the Borel presentation of the cohomology ring of orthogonal flag varieties. We use these polynomials to describe the arithmetic…

Algebraic Geometry · Mathematics 2013-09-10 Harry Tamvakis

In this tutorial, we provide an overview of many of the established combinatorial and algebraic tools of Schubert calculus, the modern area of enumerative geometry that encapsulates a wide variety of topics involving intersections of linear…

Algebraic Geometry · Mathematics 2021-05-18 Maria Gillespie

We present a proof of a Littlewood-Richardson rule for the K-theory of odd orthogonal Grassmannians OG(n,2n+1), as conjectured in [Thomas-Yong '09]. Specifically, we prove that rectification using the jeu de taquin for increasing shifted…

Combinatorics · Mathematics 2014-08-27 Edward Clifford , Hugh Thomas , Alexander Yong

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

Given a point z in P^1, let F(z) be the osculating flag to the rational normal curve at point z. The study of Schubert problems with respect to such flags F(z_1), F(z_2), ..., F(z_r) has been studied both classically and recently,…

Algebraic Geometry · Mathematics 2012-09-26 David E Speyer

We prove a root system uniform, concise combinatorial rule for Schubert calculus of_minuscule_ and_cominuscule_ flag manifolds G/P (the latter are also known as "compact Hermitian symmetric spaces"). We connect this geometry to the poset…

Algebraic Geometry · Mathematics 2010-02-17 Hugh Thomas , Alexander Yong

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

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

Let X be an orthogonal Grassmannian parametrizing isotropic subspaces in an even dimensional vector space equipped with a nondegenerate symmetric form. We prove a Giambelli formula which expresses an arbitrary Schubert class in the singular…

Algebraic Geometry · Mathematics 2012-04-02 Anders S. Buch , Andrew Kresch , Harry Tamvakis

Let $G/P$ be a generalized flag variety, where $G$ is a complex semisimple connected Lie group and $P\subset G$ a parabolic subgroup. Let also $X\subset G/P$ be a Schubert variety. We consider the canonical embedding of $X$ into a…

Symplectic Geometry · Mathematics 2009-05-28 Augustin-Liviu Mare

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

We study Schubert calculus in the torus-equivariant quantum $K$-ring of the Lagrangian Grassmannian $\mathrm{LG}(n)$. Our main tool is the $K$-theoretic Peterson map due to Kato. The map is from the (localized) equivariant $K$-homology ring…

Algebraic Geometry · Mathematics 2024-05-29 Takeshi Ikeda , Takafumi Kouno , Yusuke Nakayama , Kohei Yamaguchi

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 describe a large-scale computational experiment to study structure in the numbers of real solutions to osculating instances of Schubert problems. This investigation uncovered Schubert problems whose computed numbers of real solutions…

Algebraic Geometry · Mathematics 2013-08-21 Nickolas Hein , Christopher J. Hillar , Frank Sottile

We introduce a theory of jeu de taquin for increasing tableaux, extending fundamental work of [Sch\"{u}tzenberger '77] for standard Young tableaux. We apply this to give a new combinatorial rule for the K-theory Schubert calculus of…

Combinatorics · Mathematics 2010-02-17 Hugh Thomas , Alexander Yong

The direct sum map Gr(a,n) x Gr(b,m) -> Gr(a+b,m+n) on Grassmannians induces a K-theory pullback that defines the splitting coefficients. We geometrically explain an identity from [Buch '02] between the splitting coefficients and the…

Combinatorics · Mathematics 2011-10-17 Hugh Thomas , Alexander Yong
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