English
Related papers

Related papers: On the coproduct in affine Schubert calculus

200 papers

Let G be a reductive linear algebraic group over a field k. Let A be a finitely generated commutative k-algebra on which G acts rationally by k-algebra automorphisms. Invariant theory tells that the ring of invariants A^G=H^0(G,A) is…

Representation Theory · Mathematics 2019-12-19 Antoine Touzé , Wilberd van der Kallen

For an affine algebraic variety, we introduce algebraic Gelfand-Fuks cohomology of polynomial vector fields with coefficients in differentiable $AV$-modules. Its complex is given by cochains that are differential operators in the sense of…

Representation Theory · Mathematics 2026-02-02 Yuly Billig , Kathlyn Dykes

Given a Hopf algebra A, there exist various cohomology theories for the category of Hopf bimodules over A, introduced by M. Gerstenhaber and S.D. Schack, and by C. Ospel. We prove, when A is finite dimensional, that they are equal to the…

Quantum Algebra · Mathematics 2009-10-31 Rachel Taillefer

We explain (following V. Drinfeld) how the equivariant derived category of the affine Grassmannian can be described in terms of coherent sheaves on the Langlands dual Lie algebra equivariant with respect to the adjoint action, due to some…

Representation Theory · Mathematics 2026-02-26 Roman Bezrukavnikov , Michael Finkelberg

Using the affine web category introduced in a prequel as a building block, we formulate a diagrammatic $\Bbbk$-linear monoidal category, the affine Schur category, for any commutative ring $\Bbbk$. We then formulate diagrammatic categories,…

Representation Theory · Mathematics 2024-12-25 Linliang Song , Weiqiang Wang

The operation of tensor product of Cohomological Field Theories (or algebras over genus zero moduli operad) introduced in an earlier paper by the authors is described in full detail, and the proof of a theorem on additive relations between…

q-alg · Mathematics 2009-10-28 M. Kontsevich , Yu. Manin , R. Kaufmann

The codomain category of a generalized homology theory is the category of modules over a ring. For an abelian category A, an A-valued (generalized) homology theory is defined by formally replacing the category of modules with the category…

Algebraic Topology · Mathematics 2020-05-12 Minkyu Kim

We give a bijection between certain colored partitions and the elements in the quotient of an affine Weyl group modulo its Weyl group. By Bott's formula these colored partitions give rise to some partition identities. In certain types,…

Combinatorics · Mathematics 2008-09-28 Sara C. Billey , Stephen A. Mitchell

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

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

Let X be the flag variety of the symplectic group. We propose a theory of combinatorially explicit Schubert polynomials which represent the Schubert classes in the Borel presentation of the cohomology ring of X. We use these polynomials to…

Algebraic Geometry · Mathematics 2014-02-26 Harry Tamvakis

Let C be a coalgebra over a field k and A its dual algebra. The category of C-comodules is equivalent to a category of A-modules. We use this to interpret the cotensor product M \square N of two comodules in terms of the appropriate…

Rings and Algebras · Mathematics 2007-05-23 Lowell Abrams , Charles Weibel

We establish the formula for multiplication by the class of a special Schubert variety in the integral cohomology ring of the flag manifold. This formula also describes the multiplication of a Schubert polynomial by either an elementary…

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

We generalize the property of small-torus equivariant K-homology of the affine Grassmannian to general oriented (co)homology theory in the sense of Levine and Morel. The main tool we use is the formal affine Demazure algebra associated to…

Algebraic Geometry · Mathematics 2023-01-31 Changlong Zhong

Let G be a discrete group. We give methods to compute for a generalized (co-)homology theory its values on the Borel construction (EG x X)/G of a proper G-CW-complex X satisfying certain finiteness conditions. In particular we give formulas…

K-Theory and Homology · Mathematics 2012-01-24 Michael Joachim , Wolfgang Lueck

Our main theorem is that the inclusion of a Birkhoff variety in the affine Grassmannian is a homotopy equivalence. We also construct analogues of tubular neighborhoods for Birkhoff and Schubert varieties. We include some observations on…

Algebraic Topology · Mathematics 2009-03-30 Luke Gutzwiller , Stephen A. Mitchell

This lecture reviews the classification of simple modules of double affine Hecke algebras via the K-theory of Steinberg varieties of affine type

Representation Theory · Mathematics 2009-11-30 Michela Varagnolo , Eric Vasserot

We consider associative superalgebra realized on the smooth Grassmann-valued functions with compact supports in R^n. The lower Hochschild cohomologies of this superalgebra are found.

High Energy Physics - Theory · Physics 2007-11-13 S. E. Konstein , I. V. Tyutin

Let G be a split semi-simple p-adic group and let H be its Iwahori-Hecke algebra with coefficients in the algebraic closure k of the finite field with p elements. Let F be the affine flag variety over k associated with G. We show, in the…

Representation Theory · Mathematics 2015-10-05 Tobias Schmidt

We obtain a formula for structure constants of certain variant form of Bott-Samelson classes for equivariant oriented cohomology of flag varieties. Specializing to singular cohomology/K-theory, we recover formulas of structure constants of…

Algebraic Geometry · Mathematics 2024-04-15 Rebecca Goldin , Changlong Zhong