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Related papers: Generic character sheaves on parahoric subgroups

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We use the Springer correspondence to give a partial characterization of the irreducible representations which appear in the Tymoczko dot-action of the Weyl group on the cohomology ring of a regular semisimple Hessenberg variety. In type A,…

Representation Theory · Mathematics 2022-09-19 Ana Balibanu , Peter Crooks

We introduce, on a topological space X, a class of stacks of abelian categories we call "stacks of type P." This class of stacks includes the stack of perverse sheaves (of any perversity, constructible with respect to a fixed…

Representation Theory · Mathematics 2008-01-22 David Treumann

We associate a two-sided cell to any (parabolic) character sheaf. We study the interaction of the duality operator for character sheaves and the operation of "twisted induction".

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

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

With an eye to applications to type A and Schur-Weyl duality, we study Kazhdan-Lusztig bases for a general parabolic Hecke algebra. Parabolic Hecke algebras are idempotent subalgebras of Hecke algebras corresponding to parabolic subgroups,…

Representation Theory · Mathematics 2026-02-25 Jeremie Guilhot , Loic Poulain d'Andecy

In this article we formulate and prove the main theorems of the theory of character sheaves on unipotent groups over an algebraically closed field of characteristic p>0. In particular, we show that every admissible pair for such a group G…

Representation Theory · Mathematics 2013-01-08 Mitya Boyarchenko , Vladimir Drinfeld

In this paper, we prove Lusztig's conjecture for finite special linear groups, i.e., we show that characteristic functions of character sheaves coincide with almost characters up to scalar constants, under the condition that the…

Representation Theory · Mathematics 2007-05-23 Toshiaki Shoji

We prove a long-standing conjecture of Geck which predicts that cuspidal unipotent characters remain irreducible after $\ell$-reduction. To this end, we construct a progenerator for the category of representations of a finite reductive…

Representation Theory · Mathematics 2017-01-06 Olivier Dudas , Gunter Malle

We give a general identity relating Eisenstein series on general linear groups. We do it by constructing an Eisenstein series, attached to a maximal parabolic subgroup and a pair of representations, one cuspidal and the other a character,…

Number Theory · Mathematics 2022-12-02 Zahi Hazan

Following Lusztig, we consider a Coxeter group $W$ together with a weight function. Geck showed that the Kazhdan-Lusztig cells of $W$ are compatible with parabolic subgroups. In this paper, we generalize this argument to some subsets of $W$…

Representation Theory · Mathematics 2008-10-29 Jeremie Guilhot

In this paper, we carry out several computations involving graded (or $\mathbb{G}_{\mathrm{m}}$-equivariant) perverse-coherent sheaves on the nilpotent cone of a reductive group in good characteristic. In the first part of the paper, we…

Representation Theory · Mathematics 2019-03-11 Pramod N. Achar , William D. Hardesty

We generalize a cohomological construction of representations due to Lusztig from the hyperspecial case to arbitrary parahoric subgroups of a reductive group over a local field, which splits over an unramified extension. We compute the…

Representation Theory · Mathematics 2019-03-15 Charlotte Chan , Alexander B. Ivanov

Schneider-Stuhler and Vigneras have used cosheaves on the affine Bruhat-Tits building to construct natural finite type projective resolutions for admissible representations of reductive p-adic groups in characteristic not equal to p. We use…

Representation Theory · Mathematics 2012-06-29 Ralf Meyer , Maarten Solleveld

In this paper we construct an abelian category of "mixed perverse sheaves" attached to any realization of a Coxeter group, in terms of the associated Elias-Williamson diagrammatic category. This construction extends previous work of the…

Representation Theory · Mathematics 2018-07-19 Pramod N. Achar , Simon Riche , Cristian Vay

For a possibly twisted loop group $LG$, and any character sheaf of its Iwahori subgroup, we identify the associated affine Hecke category with a combinatorial category of Soergel bimodules. In fact, we prove such results for affine Hecke…

Representation Theory · Mathematics 2025-07-23 Gurbir Dhillon , Yau Wing Li , Zhiwei Yun , Xinwen Zhu

We show that the hypercohomology of most character twists of perverse sheaves on a complex abelian variety vanishes in all non-zero degrees. As a consequence we obtain a vanishing theorem for constructible sheaves and a relative vanishing…

Algebraic Geometry · Mathematics 2015-10-01 Thomas Krämer , Rainer Weissauer

Let $Y_{1},\dots,Y_{l}$ be smooth irreducible projective curves and let $Y$ be its disjoint union. Given a semisimple reductive algebraic group $G$ and a faithful representation $\rho:G\hookrightarrow \textrm{SL}(V)$ we construct a…

Algebraic Geometry · Mathematics 2020-07-28 Ángel Luis Muñoz Castañeda

Without using the $p$-adic Langlands correspondence, we prove that for many finite length smooth representations of $\mathrm{GL}_2(\mathbf{Q}_p)$ on $p$-torsion modules the $\mathrm{GL}_2(\mathbf{Q}_p)$-linear morphisms coincide with the…

Number Theory · Mathematics 2025-07-21 Andrea Dotto

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 X be a quasi-compact scheme, equipped with an open covering by affine schemes. A quasi-coherent sheaf on X gives rise, by taking sections over the covering sets, to a diagram of modules over the various coordinate rings. The resulting…

K-Theory and Homology · Mathematics 2010-07-30 Thomas Huettemann