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We prove a Pfaffain formula for the $K$-theory class of the degeneracy loci in the bundle of odd maximal orthogonal Grassmannians.

Algebraic Geometry · Mathematics 2016-02-16 Thomas Hudson , Takeshi Ikeda , Tomoo Matsumura , Hiroshi Naruse

We prove a determinantal formula and Pfaffian formulas that respectively describe the $K$-theoretic degeneracy loci classes for Grassmann bundles and for symplectic Grassmann and odd orthogonal bundles. The former generalizes…

Algebraic Geometry · Mathematics 2018-09-28 Thomas Hudson , Takeshi Ikeda , Tomoo Matsumura , Hiroshi Naruse

In this paper, we study Segre classes in algebraic cobordism. We also prove a generalization of Kempf-Laksov formula for the degeneracy loci classes in the algebraic cobordism of the Grassmannian bundle.

Algebraic Geometry · Mathematics 2019-09-24 Thomas Hudson , Tomoo Matsumura

In this paper, we prove a generalization of Kempf-Laksov formula for the degeneracy loci classes in even infinitesimal cohomology theories of the Grassmannian bundle and the Lagrangian Grassmannian bundle.

Algebraic Geometry · Mathematics 2019-06-25 Thomas Hudson , Tomoo Matsumura

In previous work, we employed a geometric method of Kazarian to prove Pfaffian formulas for a certain class of degeneracy loci in types B, C, and D. Here we refine that approach to obtain formulas for more general loci, including those…

Algebraic Geometry · Mathematics 2019-09-27 David Anderson , William Fulton

We give several new formulas which are useful for Schubert Calculus associated with the orthogonal groups and related orthogonal degeneracy loci.

Algebraic Geometry · Mathematics 2007-05-23 Alain Lascoux , Piotr Pragacz

We give closed-form formulas for the fundamental classes of degeneracy loci associated with vector bundle maps given locally by (not necessary square) matrices which are symmetric (resp. skew-symmetric) w.r.t. the main diagonal. Our…

Algebraic Geometry · Mathematics 2007-05-23 Alain Lascoux , Piotr Pragacz

Let V be a vector bundle on a scheme X endowed with a nondegenerate symplectic or orthogonal form. Let G be a Grassmannian bundle parametrizing maximal isotropic subbundles of V. The main goal of the paper is to give formulas for the…

alg-geom · Mathematics 2015-06-30 P. Pragacz , J. Ratajski

We study noncommutative generalizations of such notions of the classical symplectic geometry as degenerate Poisson structure, Poisson submanifold and quotient manifold, symplectic foliation and symplectic leaf for associative Poisson…

Symplectic Geometry · Mathematics 2007-05-23 Zakaria Giunashvili

Odd symplectic Grassmannians are a generalization of symplectic Grassmannians to odd-dimensional spaces. Here we compute the classical and quantum cohomology of the odd symplectic Grassmannian of lines. Although these varieties are non…

Algebraic Geometry · Mathematics 2012-01-05 Clélia Pech

In this paper, we prove determinant formulas for the $K$-theory classes of the structure sheaves of degeneracy loci classes associated to vexillary permutations in type $A$. As a consequence we obtain determinant formulas for…

Algebraic Geometry · Mathematics 2017-01-03 Thomas Hudson , Tomoo Matsumura

We study the torus equivariant Schubert classes of the Grassmannian of non-maximal isotropic subspaces in a symplectic vector space. We prove a formula that expresses each of those classes as a sum of multi Schur-Pfaffians, whose entries…

Algebraic Geometry · Mathematics 2015-06-18 Takeshi Ikeda , Tomoo Matsumura

We define a notion of vexillary signed permutation in types B, C, and D, corresponding to natural degeneracy loci for vector bundles with symmetries of those types. We show that the classes of these loci are given by explicit Pfaffian…

Algebraic Geometry · Mathematics 2012-10-09 David Anderson , William Fulton

In [BFMT17] we introduced orbital degeneracy loci as generalizations of degeneracy loci of morphisms between vector bundles. Orbital degeneracy loci can be constructed from any stable subvariety of a representation of an algebraic group. In…

Algebraic Geometry · Mathematics 2021-03-30 Vladimiro Benedetti , Sara Filippini , Laurent Manivel , Fabio Tanturri

Under the assumption that the base field k has characteristic 0, we compute the algebraic cobordism fundamental classes of a family of Schubert varieties isomorphic to full and symplectic flag bundles. We use this computation to prove a…

Algebraic Geometry · Mathematics 2015-04-30 Thomas Hudson

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

Let G be a classical complex Lie group, P any parabolic subgroup of G, and X = G/P the corresponding homogeneous space, which parametrizes (isotropic) partial flags of subspaces of a fixed vector space. In the mid 1990s, Fulton, Pragacz,…

Algebraic Geometry · Mathematics 2016-02-16 Harry Tamvakis

The quaternionic Grassmannian HGr(r,n) is the affine open subscheme of the ordinary Grassmannian parametrizing those 2r-dimensional subspaces of a 2n-dimensional symplectic vector space on which the symplectic form is nondegenerate. In…

Algebraic Geometry · Mathematics 2018-03-13 Ivan Panin , Charles Walter

We provide explicit formulas for computing the motivic Chern and Hirzebruch classes of degeneracy loci, especially those coming from the symplectic and odd orthogonal Grassmannians. The Chern-Schwartz-MacPherson classes, K-theory classes,…

Algebraic Geometry · Mathematics 2026-04-09 Minyoung Jeon

We describe here a degeneration of the symplectic desingularization of the moduli spaces of topologically trivial $GL(2,\mathbb{C})$ and $SL(2,\mathbb{C})$-Higgs bundles over a hyperelliptic curve, into O'Grady's ten and six dimensional…

Algebraic Geometry · Mathematics 2022-10-11 Emilio Franco
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