English
Related papers

Related papers: Bisymplectic Grassmannians of planes

200 papers

This paper is the first in a series that describe a conjectural analog of the geometric Satake isomorphism for an affine Kac-Moody group. In this paper we construct a model for the singularities of some would-be Schubert varieties in the…

Algebraic Geometry · Mathematics 2019-12-19 Alexander Braverman , Michael Finkelberg

We study the three point genus zero Gromov-Witten invariants on the Grassmannians which parametrize non-maximal isotropic subspaces in a vector space equipped with a nondegenerate symmetric or skew-symmetric form. We establish Pieri rules…

Algebraic Geometry · Mathematics 2015-05-13 Anders S. Buch , Andrew Kresch , Harry Tamvakis

We study the torus equivariant K-homology ring of the affine Grassmannian $\mathrm{Gr}_G$ where $G$ is a connected reductive linear algebraic group. In type $A$, we introduce equivariantly deformed symmetric functions called the K-theoretic…

Representation Theory · Mathematics 2024-08-21 Takeshi Ikeda , Mark Shimozono , Kohei Yamaguchi

We construct an isomorphism between the (universal) spherical Hall algebra of a smooth projective curve of genus g and a convolution algebra in the (equivariant) K-theory of the genus g commuting varieties C_{{gl}_r}={(x_i, y_i) \in…

Quantum Algebra · Mathematics 2010-09-06 O. Schiffmann , E. Vasserot

We prove that any three-point genus zero Gromov-Witten invariant on a type A Grassmannian is equal to a classical intersection number on a two-step flag variety. We also give symplectic and orthogonal analogues of this result; in these…

Algebraic Geometry · Mathematics 2007-05-23 Anders Skovsted Buch , Andrew Kresch , Harry Tamvakis

In this work, we introduce a variant of the Grothendieck-Teichm{\"u}ller group, defined in terms of complements of hyperplane arrangements and pro-$\ell$ two-step nilpotent fundamental groups, and prove that it is isomorphic to the absolute…

Algebraic Geometry · Mathematics 2025-09-30 Florian Pop , Adam Topaz

Denote by $\mathbb G(k,n)$ the Grassmannian of linear subspaces of dimension $k$ in $\mathbb P^n$. We show that, if $\varphi:\mathbb G(l,n) \to \mathbb G(k,n)$ is a non constant morphism and $l \not=0,n-1$ then $l=k$ or $l=n-k-1$ and…

Algebraic Geometry · Mathematics 2025-04-01 Gianluca Occhetta , Eugenia Tondelli

We prove that, for m greater than 3 and k greater than m-2, the Grassmannian of m-dimensional subspaces of the space of skew-symmetric forms over a vector space of dimension 2k is birational to the Hilbert scheme of Palatini scrolls in…

Algebraic Geometry · Mathematics 2009-11-23 Daniele Faenzi , Maria Lucia Fania

We construct a natural prequantization space over a monotone product of a toric manifold and an arbitrary number of complex Grassmannians of 2-planes in even-dimensional complex spaces, and prove that the universal cover of the identity…

Symplectic Geometry · Mathematics 2019-02-08 Frol Zapolsky

We prove that Schubert varieties in potentially different Grassmannians are isomorphic as varieties if and only if their corresponding Young diagrams are identical up to a transposition. We also discuss a generalization of this result to…

Algebraic Geometry · Mathematics 2023-09-13 Mihail Tarigradschi , Weihong Xu

In this paper, we study the T_w-equivariant cohomology of the weighted Grassmannians wGr(d,n) introduced by Corti-Reid where T_w is the n-dimensional torus that naturally acts on wGr(d,n). We introduce the equivariant weighted Schubert…

Algebraic Topology · Mathematics 2013-10-30 Hiraku Abe , Tomoo Matsumura

We provide a unified geometric realization of the classical deformation complexes. We construct GL-equivariant bilinear incidence varieties whose diagonal slices recover the varieties of associative, commutative, Leibniz, and Lie algebra…

Rings and Algebras · Mathematics 2025-11-24 Atabey Kaygun

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…

Algebraic Geometry · Mathematics 2016-09-07 Frank Sottile

Given a complex vector space $V$ of finite dimension, its Grassmannian variety parametrizes all subspaces of $V$ of a given dimension. Similarly, if a finite group $G$ acts on $V$, its invariant Grassmannian parametrizes all the…

Algebraic Geometry · Mathematics 2024-05-01 Stevell Muller

Given integers $n \geq k \geq d$, let $X_{n,k,d}$ be the moduli space of $n$-tuples of lines $(\ell_1, \dots, \ell_n)$ in $\mathbb{C}^k$ such that $\ell_1 + \cdots + \ell_n$ has dimension $d$. We give a quotient presentation of the…

Combinatorics · Mathematics 2024-12-10 Raymond Chou , Tomoo Matsumura , Brendon Rhoades

MacPherson conjectured that the Grassmannian $\mathrm{Gr}(2, \mathbb{R}^n)$ has the same homeomorphism type as the combinatorial Grassmannian $\|\mbox{MacP}(2,n)\|$, while Babson proved that the spaces $\mathrm{Gr}(2,\mathbb{R}^n)$ and…

Combinatorics · Mathematics 2022-10-11 Olakunle S Abawonse

We introduce a class of equivariant vector bundles on isotropic symplectic Grassmannians $\mathrm{IGr}(k,2n)$ defined as appropriate truncations of staircase complexes and show that these bundles can be assembled into a number of complexes…

Algebraic Geometry · Mathematics 2024-12-05 Alexander Novikov

We give a Pieri rule for the torus-equivariant cohomology of (submaximal) Grassmannians of Lie types B, C, and D. To the authors' best knowledge, our rule is the first manifestly positive formula, beyond the equivariant Chevalley formula.…

Algebraic Geometry · Mathematics 2015-07-08 Changzheng Li , Vijay Ravikumar

We consider the semi-direct products $G=\mathbb Z^2\rtimes GL_2(\mathbb Z), \mathbb Z^2\rtimes SL_2(\mathbb Z)$ and $\mathbb Z^2\rtimes\Gamma(2)$ (where $\Gamma(2)$ is the congruence subgroup of level 2). For each of them, we compute both…

Operator Algebras · Mathematics 2023-11-28 Ramon Flores , Sanaz Pooya , Alain Valette

Let $G$ be a complex reductive group. A folklore result asserts the existence of an $\mathbb{E}_2$-algebra structure on the Ran Grassmannian of $G$ over $\mathbb{A}^1_{\mathbb{C}}$, seen as a topological space with the complex-analytic…

Algebraic Topology · Mathematics 2025-10-03 Guglielmo Nocera , Morena Porzio