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Related papers: On Koszul duality for Kac-Moody groups

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This article establishes a geometric Satake equivalence for affine Kac-Moody groups as an equivalence of abelian semisimple categories over algebraically closed fields. We define a well-behaved category of equivariant sheaves on the double…

Representation Theory · Mathematics 2025-10-22 Alexis Bouthier , Eric Vasserot

For a countable group $G$ we construct a small, idempotent complete, symmetric monoidal, stable $\infty$-category $\mathrm{KK}^{G}_{\mathrm{sep}}$ whose homotopy category recovers the triangulated equivariant Kasparov category of separable…

Operator Algebras · Mathematics 2025-12-03 Ulrich Bunke , Alexander Engel , Markus Land

A well-known and old result of Hazewinkel and Koszul states that the cohomology of a finite-dimensional Lie algebra is isomorphic, up to a suitable shift, to its twisted homology, a Lie-theoretical version of Poincare duality. This paper…

Quantum Algebra · Mathematics 2026-01-26 Andrey Lazarev , Rong Tang

We describe a new geometric model for the Hochschild cohomology of Soergel bimodules based on the monodromic Hecke category studied earlier by the first author and Yun. Moreover, we identify the objects representing individual Hochschild…

Representation Theory · Mathematics 2022-01-14 Roman Bezrukavnikov , Kostiantyn Tolmachov

We prove that the adjoint equivariant derived category of a reductive group $G$ is equivalent to the appropriately defined monoidal center of the torus-equivariant version of the Hecke category. We use this to give new proofs, independent…

Representation Theory · Mathematics 2024-06-13 Roman Bezrukavnikov , Andrei Ionov , Kostiantyn Tolmachov , Yakov Varshavsky

Let $\mathcal{U}$ be the unipotent variety of a complex reductive group $G$. Fix opposed Borel subgroups $B_\pm \subseteq G$ with unipotent radicals $U_\pm$. The map that sends $x_+x_- \mapsto x_+x_-x_+^{-1}$ for all $x_\pm \in U_\pm$…

Representation Theory · Mathematics 2022-10-18 Minh-Tâm Quang Trinh

Let G be a connected complex reductive group and let K be a symmetric subgroup of G. We prove a formula for the Drinfeld-Gaitsgory functor for the dg-category of K-equivariant sheaves on the flag manifold of G in terms of the Matsuki…

Representation Theory · Mathematics 2021-12-30 Tsao-Hsien Chen

The "linear dual" of a cocomplete linear category $\mathcal C$ is the category of all cocontinuous linear functors $\mathcal C \to \mathrm{Vect}$. We study the questions of when a cocomplete linear category is reflexive (equivalent to its…

Category Theory · Mathematics 2020-01-31 Martin Brandenburg , Alexandru Chirvasitu , Theo Johnson-Freyd

We propose a new framework for categorifying skew-symmetrizable cluster algebras. Starting from an exact stably 2-Calabi-Yau category C endowed with the action of a finite group G, we construct a G-equivariant mutation on the set of maximal…

Representation Theory · Mathematics 2015-09-04 Laurent Demonet

For a smooth affine algebraic group $G$, one can attach various D-module categories to it that admit convolution monoidal structure. We consider the derived category of D-modules on $G$, the stack $G/G_{ad}$ and the category of…

Representation Theory · Mathematics 2026-01-15 Wenjun Niu

We prove in this paper a Borel-Weil-Bott type theorem for the coHochschild homology of a quantum shuffle algebra associated with quantum group datum taking coefficients in some well-chosen bicomodules, which can be looked as an analogue of…

Quantum Algebra · Mathematics 2012-08-30 Xin Fang

We study a version of the BGG category O for Dynkin Borel subalgebras of root-reductive Lie algebras g, such as gl(\infty). We prove results about extension fullness and compute the higher extensions of simple modules by Verma modules. In…

Representation Theory · Mathematics 2019-03-20 Kevin Coulembier , Ivan Penkov

In this paper we continue the study (initiated in a previous article) of linear Koszul duality, a geometric version of the standard duality between modules over symmetric and exterior algebras. We construct this duality in a very general…

Representation Theory · Mathematics 2017-05-17 Ivan Mirković , Simon Riche

We describe the cohomology groups of a homogeneous vector bundle $E$ on any Hermitian symmetric variety $X=G/P$ of ADE type as the cohomology of a complex explicitly described. The main tool is the equivalence between the category of…

Algebraic Geometry · Mathematics 2007-05-23 Giorgio Ottaviani , Elena Rubei

Various monoidal categories, including suitable representation categories of vertex operator algebras, admit natural Grothendieck-Verdier duality structures. We recall that such a Grothendieck-Verdier category comes with two tensor products…

Category Theory · Mathematics 2024-12-13 Jürgen Fuchs , Gregor Schaumann , Christoph Schweigert , Simon Wood

Given an effective Cartier divisor D with simple normal crossing support on a smooth and proper scheme X over a perfect field of positive characteristic p, there is a natural notion of de Rham-Witt sheaves on X with zeros along D. We show…

Algebraic Geometry · Mathematics 2024-03-28 Fei Ren , Kay Rülling

Two rings A and B are said to be derived Morita equivalent if their derived categories of modules are equivalent. By results of Rickard, if A and B are derived Morita equivalent algebras over a field k, then there is a complex of bimodules…

Rings and Algebras · Mathematics 2007-05-23 Amnon Yekutieli

This is an extended abstract of our work "Level-Rank Dualities from $\Phi$-Cuspidal Pairs..." We present evidence for a family of surprising coincidences within the representation theory of a finite reductive group $G$: more precisely,…

Representation Theory · Mathematics 2025-08-12 Minh-Tâm Quang Trinh , Ting Xue

We construct twisted $\mathcal{D}$-modules on the projective line $\mathbb{P}^1$ that are equivariant for the action of the diagonal torus subgroup of $SL_2$. In the most interesting case these arise as extensions from local systems on…

Representation Theory · Mathematics 2015-09-18 Claude Eicher

Let $E\to B$ be a complex analytic fiber bundle with fiber $F$, a flag variety over a compact complex manifold $B$. We shall obtain a description of the cohomology of $E$ when $B=X_\Gamma:=\Gamma\backslash X, E=Y_\Gamma:=\Gamma\backslash Y$…

Differential Geometry · Mathematics 2024-07-12 Pritthijit Biswas , Parameswaran Sankaran