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Related papers: Perverse sheaves and modular representation theory

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We relate a certain category of sheaves of k-vector spaces on a complex affine Schubert variety to modules over the k-Lie algebra (for ch k>0) or to modules over the small quantum group (for ch k=0) associated to the Langlands dual root…

Representation Theory · Mathematics 2010-11-12 Peter Fiebig

A class of perverse sheaves on framed representation varieties of the Jordan quiver is defined. Its relationship with product of symmetric groups, tensor product of Schur algebras, and tensor product of Fock spaces are addressed.

Representation Theory · Mathematics 2012-09-18 Yiqiang Li

In this article, we study the modular representations of the special linear group of degree two over a finite field in defining characteristic. In particular, we study the automorphisms of derived category of representations. We have been…

Representation Theory · Mathematics 2017-07-19 William Wong

The main goal of this paper is to establish close relations among sheaves of modules on atomic sites, representations of categories, and discrete representations of topological groups. We characterize sheaves of modules on atomic sites as…

Representation Theory · Mathematics 2025-05-07 Zhenxing Di , Liping Li , Li Liang , Fei Xu

We give a complete quiver description of the category of perverse sheaves on Hermitian symmetric spaces in types A and D, constructible with respect to the Schubert stratification. The calculation is microlocal, and uses the action of the…

Algebraic Geometry · Mathematics 2007-05-23 Tom Braden

In the strict semi stable reduction situation, we describe the various filtrations of the perverse sheaf of nearby cycles in terms of irreducible perverse sheaves together with the action of the monodromy operator. We then study the…

Algebraic Geometry · Mathematics 2026-01-06 Pascal Boyer

The method of intersection spaces associates rational Poincar\'e complexes to singular stratified spaces. For a conifold transition, the resulting cohomology theory yields the correct count of all present massless 3-branes in type IIB…

Algebraic Geometry · Mathematics 2016-05-24 Markus Banagl , Nero Budur , Laurentiu Maxim

We study a class of perverse sheaves on some spherical varieties which include the strata of the De Concini-Procesi completion of a symmetric variety. This is a generalization of the theory of (parabolic) character sheaves.

Representation Theory · Mathematics 2007-05-23 Xuhua He

The Springer correspondence makes a link between the characters of a Weyl group and the geometry of the nilpotent cone of the corresponding semisimple Lie algebra. In this article, we consider a modular version of the theory, and show that…

Representation Theory · Mathematics 2014-10-07 Daniel Juteau

This paper is the first in a series of papers in which we define and study a category of "sheaves of $\mathcal Z$-modules on the set of alcoves" that carries important information on the category of representations of semisimple Lie…

Representation Theory · Mathematics 2017-01-16 Peter Fiebig , Martina Lanini

Let X be a noetherian scheme defined over an algebraically closed field of positive characteristic p, and G be a finite group, of order divisible by p, acting on X. We introduce a refinement of the equivariant K-theory of X to take into…

Number Theory · Mathematics 2007-05-23 Niels Borne

For any field $k$, we give an algebraic description of the category $\mathrm{Perv}_\mathscr{S}(S^n (\mathbb{C}^2),k)$ of perverse sheaves on the $n$-fold symmetric product of the plane $S^n(\mathbb{C}^2)$ constructible with respect to its…

Algebraic Geometry · Mathematics 2024-09-20 Tom Braden , Carl Mautner

We study some aspects of modular generalized Springer theory for a complex reductive group $G$ with coefficients in a field $\mathbb k$ under the assumption that the characteristic $\ell$ of $\mathbb k$ is rather good for $G$, i.e., $\ell$…

Representation Theory · Mathematics 2017-04-11 Pramod Achar , Anthony Henderson , Daniel Juteau , Simon Riche

We define a new perverse t-exact pullback operation on derived categories of constructible sheaves which generalizes most perverse t-exact functors in sheaf theory, such as microlocalization, the Fourier-Sato transform and vanishing cycles.…

Algebraic Geometry · Mathematics 2025-10-21 Adeel A. Khan , Tasuki Kinjo , Hyeonjun Park , Pavel Safronov

In 1976, Springer defined a correspondence making a link between the irreducible ordinary (characteristic zero) representations of a Weyl group and the geometry of the associated nilpotent variety. In this thesis, we define a modular…

Representation Theory · Mathematics 2009-01-26 Daniel Juteau

We describe the relationship between intersection cohomology with twisted coefficients and the perverse sheaves which play the role of the eigenspaces for the Milnor monodromy of an affine hypersurface.

Algebraic Geometry · Mathematics 2019-02-04 David B. Massey

Another introduction to perverse sheaves with some exercises. Expanded version of five lectures at the 2015 PCMI.

Algebraic Geometry · Mathematics 2016-11-15 Mark Andrea A. de Cataldo

For a complex reductive Lie group G with Lie algebra g, Cartan subalgebra h and Weyl group W, we describe the category of perverse sheaves on h/W smooth w.r.t the natural stratification. The answer is given in terms of mixed Bruhat sheaves,…

Algebraic Topology · Mathematics 2021-12-14 Mikhail Kapranov , Vadim Schechtman

We relate the category of sheaves on alcoves that was constructed in "Sheaves on the alcoves and modular representations I" to the representation theory of reductive algebraic groups. In particular, we show that its indecomposable…

Representation Theory · Mathematics 2020-04-07 Peter Fiebig , Martina Lanini

Perverse schobers are conjectural categorical analogs of perverse sheaves. We show that such structures appear naturally in Homological Minimal Model Program which studies the effect of birational transformations such as flops, on the…

Algebraic Geometry · Mathematics 2018-01-26 Alexey Bondal , Mikhail Kapranov , Vadim Schechtman