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Related papers: Character sheaves on certain spherical varieties

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We provide a description of Iwahori-Whittaker equivariant perverse sheaves on affine flag varieties associated to tamely ramified reductive groups, in terms of Langlands dual data. This extends the work of Arkhipov-Bezrukavnikov from the…

Representation Theory · Mathematics 2024-11-06 Rızacan Çiloğlu

It is given the diffeomorphism classification on generic singularities of tangent varieties to curves with arbitrary codimension in a projective space. The generic classifications are performed in terms of certain geometric structures and…

Differential Geometry · Mathematics 2012-02-16 Goo Ishikawa

We analyse infinitesimal deformations of morphisms of locally free sheaves on a smooth projective variety $X$ over an algebraically closed field of characteristic zero. In particular, we describe a differential graded Lie algebra…

Algebraic Geometry · Mathematics 2025-03-05 Donatella Iacono , Elena Martinengo

We show in this paper that in the context of graded Lie algebras, all cuspidal character sheaves arise from a nearby-cycle construction followed by a Fourier--Sato transform in a very specific manner. Combined with results of the last two…

Representation Theory · Mathematics 2025-12-29 Wille Liu , Cheng-Chiang Tsai , Kari Vilonen , Ting Xue

In this note, we provide a quick introduction to the study of the Milnor fibration via the derived category and perverse sheaves. This is primarily a dictionary for translating from the standard topological setting to the derived category…

Algebraic Geometry · Mathematics 2012-07-31 David B. Massey

In this paper we construct full support character sheaves for stably graded Lie algebras. Conjecturally these are precisely the cuspidal character sheaves. Irreducible representations of Hecke algebras associated to complex reflection…

Representation Theory · Mathematics 2025-03-25 Kari Vilonen , Ting Xue

Motivated by the polynomial representation theory of the general linear group and the theory of symplectic singularities, we study a category of perverse sheaves with coefficients in a field $k$ on any affine unimodular hypertoric variety.…

Algebraic Geometry · Mathematics 2017-09-12 Tom Braden , Carl Mautner

Perverse-Hodge complexes are objects in the derived category of coherent sheaves obtained from Hodge modules associated with Saito's decomposition theorem. We study perverse-Hodge complexes for Lagrangian fibrations and propose a symmetry…

Algebraic Geometry · Mathematics 2026-05-27 Junliang Shen , Qizheng Yin

We study the equivariant cohomology of spherical perverse sheaves on the affine Grassmannian of a connected reductive group $G$ with support in the affine Grassmannian of any Levi subgroup $L$ of $G$. In doing so, we extend the work of…

Representation Theory · Mathematics 2023-09-19 Mark Macerato

From a block-diagonal $(n+1) \times (m+1) \times (m+1)$ tensor symmetric in the last two entries one obtains two varieties: an intersection of symmetric determinantal hypersurfaces $X$ in $n$-dimensional projective space, and an…

Algebraic Geometry · Mathematics 2021-09-21 Avinash Kulkarni , Sameera Vemulapalli

We study the compatibility with proper push-forward of the characteristic cycles of a constructible complex on a smooth variety over a perfect field.

Algebraic Geometry · Mathematics 2020-03-24 Takeshi Saito

We give a projective proof of the butterfly porism for cyclic quadrilaterals and present a general reversion porism for polygons with an arbitrary number of vertices on a conic. We also investigate projective properties of the porisms.

Algebraic Geometry · Mathematics 2021-08-17 Lorenz Halbeisen , Norbert Hungerbühler , Marco Schiltknecht

We propose a point of view on resurgence theory based on the study of perverse sheaves on the complex line carrying an algebraic structure with respect to additive convolution. In particular, we lift the concept of alien derivatives…

Algebraic Geometry · Mathematics 2025-12-30 Mikhail Kapranov , Yan Soibelman

This paper is an introduction, in a simplified setting, to Lusztig's theory of character sheaves. It develops a notion of character sheaves on reductive Lie algebras which is more general then such notion of Lusztig, and closer to Lusztig's…

Representation Theory · Mathematics 2007-05-23 Ivan Mirkovic

We introduce techniques of Suslin, Voevodsky, and others into the study of singular varieties. Our approach is modeled after Goresky-MacPherson intersection homology. We provide a formulation of perversity cycle spaces leading to perversity…

K-Theory and Homology · Mathematics 2019-02-20 Eric M. Friedlander , Joseph Ross

We introduce a singular chain intersection homology theory which generalizes that of King and which agrees with the Deligne sheaf intersection homology of Goresky and MacPherson on any topological stratified pseudomanifold, compact or not,…

Geometric Topology · Mathematics 2011-03-31 Greg Friedman

In this article, the theory of sheaves is studied from a categorical point of view. This perspective vastly generalizes the usual theory of sheaves of sets to a more abstract setting which allows us to investigate the theory of sheaves with…

Commutative Algebra · Mathematics 2017-09-22 Abolfazl Tarizadeh

The goal of these lectures is to explain speaker's results on uniqueness properties of spherical varieties. By a uniqueness property we mean the following. Consider some special class of spherical varieties. Define some combinatorial…

Algebraic Geometry · Mathematics 2009-05-30 Ivan Losev

A superspecial curve is a (non-singular) curve over a field of positive characteristic whose Jacobian variety is isomorphic to a product of supersingular elliptic curves over the algebraic closure. It is known that for given genus and…

Algebraic Geometry · Mathematics 2021-10-04 Momonari Kudo

In this paper, we provide a relative hypercohomology version of Serre's GAGA theorem. We prove that the relative hypercohomology of a complex of sheaves on a complex projective variety is isomorphic to the relative hypercohomology of its…

Algebraic Geometry · Mathematics 2024-09-11 Eita Haibara , Taewan Kim