English
Related papers

Related papers: Sheaves on the alcoves and modular representations…

200 papers

We present a uniform theory of constructible sheaves on arbitrary schemes with coefficients in topological or even condensed rings. This is accomplished by defining lisse sheaves to be the dualizable objects in the derived infinity-category…

Algebraic Geometry · Mathematics 2023-05-30 Tamir Hemo , Timo Richarz , Jakob Scholbach

We study representations of the double affine Lie algebra associated to a simple Lie algebra. We construct a family of indecomposable integrable representations and identify their irreducible quotients. We also give a condition for the…

Quantum Algebra · Mathematics 2007-05-23 Vyjayanthi Chari , Thang Le

We study three fundamental topics in the representation theory of disconnected algebraic groups whose identity component is reductive: (i) the classification of irreducible representations; (ii) the existence and properties of Weyl and dual…

Representation Theory · Mathematics 2020-09-09 P. Achar , W. Hardesty , S. Riche

An axiomatic approach to the representation theory of Coxeter groups and their Hecke algebras was presented in [1]. Combinatorial aspects of this construction are studied in this paper. In particular, the symmetric group case is…

Representation Theory · Mathematics 2007-05-23 Ron M. Adin , Francesco Brenti , Yuval Roichman

We study a category of semiinfinite sheaves on the affine flag variety of a connected reductive algebraic group, with coefficients in a field of arbitrary characteristic, generalizing some results of Gaitsgory and showing that this category…

Representation Theory · Mathematics 2025-03-25 Pramod N. Achar , Gurbir Dhillon , Simon Riche

In type theory, an oracle may be specified abstractly by a predicate whose domain is the type of queries asked of the oracle, and whose proofs are the oracle answers. Such a specification induces an oracle modality that captures a…

Logic · Mathematics 2026-04-30 Danel Ahman , Andrej Bauer

Jensen, Su, and Yang described the projective indecomposable modules of the $0$-Schur algebra $\mathbf{S}_0(n,r)$ using its geometric realization. In this paper, the simple modules of $\mathbf{S}_0(n,r)$ are identified by computing the tops…

Representation Theory · Mathematics 2025-11-18 Woo-Seok Jung , Young-Tak Oh

This paper contains an exposition of the theory of character sheaves for reductive groups and some attempts to extend it to other cases: unipotent groups, reductive groups modulo the unipotent radical of a parabolic.

Representation Theory · Mathematics 2007-05-23 G. Lusztig

In this paper we prove equivalences of categories relating the derived category of a block of the category of representations of a connected reductive algebraic group over an algebraically closed field of characteristic $p$ bigger than the…

Representation Theory · Mathematics 2018-04-13 Pramod N. Achar , Simon Riche

We prove a microlocal characterisation of character sheaves on a reductive Lie algebra over an algebraically closed field of sufficiently large positive characteristic: a perverse irreducible G-equivariant sheaf is a character sheaf if and…

Representation Theory · Mathematics 2024-05-14 Tong Zhou

In this paper we continue the study of character sheaves on a reductive group G. To each subset of the set of simple reflections in the Weyl group we associate an algebra of the same kind as an Iwahori-Hecke algebra with unequal parameters…

Representation Theory · Mathematics 2007-05-23 G. Lusztig

We begin the study of character sheaves on a not necessarily connected reductive group, extending the known theory for connected groups.

Representation Theory · Mathematics 2007-05-23 G. Lusztig

We define a sheaf of abelian groups whose cohomology is represented by the cotangent complex. We show how obstructions to some standard deformation problems arise as the classes of torsors under and gerbes banded by this sheaf.

Algebraic Geometry · Mathematics 2011-07-13 Jonathan Wise

The representation theory of semisimple algebraic groups over the complex numbers (equivalently, semisimple complex Lie algebras or Lie groups, or real compact Lie groups) and the question of whether a given representation is symplectic or…

Group Theory · Mathematics 2016-04-13 Skip Garibaldi , Daniel K. Nakano

There are two approaches to projective representation theory of symmetric and alternating groups, which are powerful enough to work for modular representations. One is based on Sergeev duality, which connects projective representation…

Representation Theory · Mathematics 2010-11-03 Alexander Kleshchev , Vladimir Shchigolev

We develop a theory of general sheaves over weighted projective lines. We define and study a canonical decomposition, analogous to Kac's canonical decomposition for representations of quivers, study subsheaves of a general sheaf, general…

Algebraic Geometry · Mathematics 2007-09-24 William Crawley-Boevey

Let D be a connected component of a reductive group over an algebraically closed field. We define a surjective map from the unipotent character sheaves on D to the set of strata of D, extending an earlier result which applied to connected…

Representation Theory · Mathematics 2023-04-19 G. Lusztig

We construct projective (unitary) representations of Hecke groups from the vector spaces associated with the Witten-Reshetikhin-Turaev topological quantum field theory of higher genus surfaces. In particular, we generalize the modular data…

Geometric Topology · Mathematics 2024-11-27 Yuze Ruan

In geometric representation theory, one often wishes to describe representations realized on spaces of invariant functions as trace functions of equivariant perverse sheaves. In the case of principal series representations of a connected…

Algebraic Geometry · Mathematics 2011-07-29 Masoud Kamgarpour , Travis Schedler

This is the second paper in a series on representations over diagrams of abelian categories. We show that, under certain conditions, a compatible family of abelian model categories indexed by a skeletal small category can be amalgamated…

Category Theory · Mathematics 2025-06-23 Zhenxing Di , Liping Li , Li Liang , Nina Yu