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Related papers: Generic character sheaves on parahoric subgroups

200 papers

We revisit generic vanishing results for perverse sheaves with any field coefficients on a complex semi-abelian variety, and indicate several topological applications. In particular, we obtain finiteness properties for the integral…

Algebraic Topology · Mathematics 2017-08-01 Yongqiang Liu , Laurentiu Maxim , Botong Wang

Let X be a smooth projective connected curve over an algebraically closed field k of positive characteristic. Let G be a reductive group over k, \gamma be a dominant coweight for G, and E be an \ell-adic \check{G}-local system on X, where…

Representation Theory · Mathematics 2016-09-07 Sergey Lysenko

We extend a result of Yun on minimal reduction types to the parahoric case. This implies a uniqueness property for 2-special representations appearing in the cohomology of certain affine Springer fibers. Using this, we settle a conjecture…

Representation Theory · Mathematics 2025-04-08 Anlong Chua

Using $\ell$-adic cohomology of tensor inductions of lisse $\overline{\mathbb Q}_\ell$-sheaves, we study a class of incomplete character sums.

Algebraic Geometry · Mathematics 2025-01-07 Lei Fu , Daqing Wan

We relate a generic character sheaf on a disconnected reductive group with a character of a representation of the rational points of the group over a finite field extending a result known in the connected case.

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

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

For a complex reductive Lie algebra $\mathfrak{g}$ with Cartan subalgebra $\mathfrak{h}$ and Weyl group $W$ we consider the category $\text{Perv}(W \backslash \mathfrak{h})$ of perverse sheaves on $W \backslash \mathfrak{h}$ smooth w.r.t.…

Representation Theory · Mathematics 2024-12-03 Mikhail Kapranov , Vadim Schechtman , Olivier Schiffmann , Jiangfan Yuan

It is known that in the case of hyperelliptic curves the Shafarevich conjecture can be made effective, i.e., for any number field k and any finite set of places S of k, one can effectively compute the set of isomorphism classes of…

Number Theory · Mathematics 2012-03-06 Aaron Levin

The aim of these notes is to generalize Laumon's construction [18] of automorphic sheaves corresponding to local systems on a smooth, projective curve $C$ to the case of local systems with indecomposable unipotent ramification at a finite…

Algebraic Geometry · Mathematics 2007-05-23 Jochen Heinloth

In my 2009 paper at Inventiones, we determine the cohomology of Lubin-Tate spaces globally using the comparison theorem of Berkovich by computing the fibers at supersingular points of the perverse sheaf of vanishing cycle $\Psi$ of some…

Number Theory · Mathematics 2022-11-14 Pascal Boyer

For a classical group over a non-archimedean local field of odd residual characteristic p, we construct all cuspidal representations over an arbitrary algebraically closed field of characteristic different from p, as representations induced…

Representation Theory · Mathematics 2015-11-30 Robert Kurinczuk , Shaun Stevens

The study of Haeflier suggests that it is natural to regard a pseudogroup as an etale groupoid. We show that any etale groupoid corresponds to a pseudogroup sheaf, a new generalization of a pseudogroup. This correspondence is an analog of…

Category Theory · Mathematics 2021-08-03 Koji Yamazaki

In this paper we provide a "combinatorial" description of the category of tilting perverse sheaves on the affine flag variety of a reductive algebraic group, and its free-monodromic variant, with coefficients in a field of positive…

Representation Theory · Mathematics 2024-07-08 Roman Bezrukavnikov , Simon Riche

We investigate deformations of a skew group algebra that arise from a finite group acting on a polynomial ring. When the characteristic of the underlying field divides the order of the group, a new type of deformation emerges that does not…

Rings and Algebras · Mathematics 2013-12-13 Anne V. Shepler , Sarah Witherspoon

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

We give an explicit combinatorial description of the category Perv(S,N) of perverse sheaves on an oriented surface S (with boundary) with singularities at a given finite set N. The description is given in terms of any spanning graph K in S…

Algebraic Topology · Mathematics 2016-01-11 Mikhail Kapranov , Vadim Schechtman

We show that Lusztig's conjecture on the irreducible characters of a reductive algebraic group over a field of positive characteristic is equivalent to the generic multiplicity conjecture, which gives a formula for the Jordan-H"older…

Representation Theory · Mathematics 2011-01-13 Peter Fiebig

We show that the category of coherent sheaves on the toric boundary divisor of a smooth quasiprojective toric DM stack is equivalent to the wrapped Fukaya category of a hypersurface in a complex torus. Hypersurfaces with every Newton…

Symplectic Geometry · Mathematics 2023-04-18 Benjamin Gammage , Vivek Shende

For oriented $-1$-shifted symplectic derived Artin stacks, Ben-Bassat-Brav-Bussi-Joyce introduced certain perverse sheaves on them which can be regarded as sheaf theoretic categorifications of the Donaldson-Thomas invariants. In this paper,…

Algebraic Geometry · Mathematics 2022-02-09 Tasuki Kinjo

In this paper we prove a toric localization formula in the cohomological Donaldson-Thomas theory. Consider a (-1)-shifted symplectic algebraic space with a $\mathbb{G}_m$-action leaving the (-1)-shifted symplectic form invariant (typical…

Algebraic Geometry · Mathematics 2025-06-30 Pierre Descombes
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