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Related papers: Constructible sheaves on schemes

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In this paper we study the derived category of sheaves on the affine Grassmannian of a complex reductive group G, contructible with respect to the stratification by G(C[[x]])-orbits. Following ideas of Ginzburg and…

Representation Theory · Mathematics 2011-02-15 Pramod N. Achar , Simon Riche

Given a stratified variety X with strata satisfying a cohomological parity-vanishing condition, we define and show the uniqueness of "parity sheaves", which are objects in the constructible derived category of sheaves with coefficients in…

Representation Theory · Mathematics 2016-03-31 Daniel Juteau , Carl Mautner , Geordie Williamson

We introduce a notion of constructibility for \'etale sheaves with torsion coefficients over a suitable class of adic spaces. This notion is related to the classical notion of constructibility for schemes via the nearby cycles functor. We…

Algebraic Geometry · Mathematics 2017-07-13 Ildar Gaisin , John Welliaveetil

We develop a "Soergel theory" for Bruhat-constructible perverse sheaves on the flag variety $G/B$ of a complex reductive group $G$, with coefficients in an arbitrary field $\Bbbk$. Namely, we describe the endomorphisms of the projective…

Representation Theory · Mathematics 2020-02-19 Roman Bezrukavnikov , Simon Riche

This note is mostly an exposition of an unpublished result of Deligne, which introduces an analogue of perverse $t$-structure on the derived category of coherent sheaves on a Noetherian scheme with a dualizing complex. Construction extends…

Algebraic Geometry · Mathematics 2010-06-24 Roman Bezrukavnikov

The aim of this note is threefold. The first is to obtain a simple characterization of relative constructible sheaves when the parameter space is projective. The second is to study the relative Fourier-Mukai for relative constructible…

Algebraic Geometry · Mathematics 2025-08-19 Luisa Fiorot , Teresa Monteiro Fernandes

In this paper we introduce constructible analogs of the discrete complexity classes $\mathbf{VP}$ and $\mathbf{VNP}$ of sequences of functions. The functions in the new definitions are constructible functions on $\mathbb{R}^n$ or…

Algebraic Geometry · Mathematics 2017-10-09 Saugata Basu

It is usually not straightforward to work with the category of perverse sheaves on a variety using only its definition as a heart of a $t$-structure. In this paper, the category of perverse sheaves on a smooth toric variety with its orbit…

Algebraic Geometry · Mathematics 2024-12-30 Sergey Guminov

In this paper we prove an equivalence theorem originally observed by Robert MacPherson. On one side of the equivalence is the category of cosheaves that are constructible with respect to a locally cone-like stratification. Our…

Algebraic Topology · Mathematics 2021-10-18 Justin Curry , Amit Patel

We prove an analog of the Gauss-Bonnet formula for constructible sheaves on reductive groups. As a corollary from this formula we get that if a perverse sheaf on a reductive group is equivariant under the adjoint action, then its Euler…

Algebraic Geometry · Mathematics 2007-05-23 Valentina Kiritchenko

Graded Hecke algebras can be constructed in terms of equivariant cohomology and constructible sheaves on nilpotent cones. In earlier work, their standard modules and their irreducible modules where realized with such geometric methods. We…

Representation Theory · Mathematics 2025-01-20 Maarten Solleveld

In the setting of the unbounded derived category D(R) of a ring R of weak global dimension at most one we consider t-structures with a definable coaisle. The t-structures among these which are stable (that is, the t-structures which consist…

Commutative Algebra · Mathematics 2020-08-03 Silvana Bazzoni , Michal Hrbek

For a smooth proper scheme over a local field of mixed characteristics which has semistable reduction we define the category of its semistable etale sheaves and under certain hypothesis we prove the appropriate semistable comparison…

Algebraic Geometry · Mathematics 2012-12-18 Fabrizio Andreatta , Adrian Iovita

We show that compatible systems of $\ell$-adic sheaves on a scheme of finite type over the ring of integers of a local field are compatible along the boundary up to stratification. This extends a theorem of Deligne on curves over a finite…

Algebraic Geometry · Mathematics 2019-11-13 Qing Lu , Weizhe Zheng

We show that conically smooth stratified spaces embed fully faithfully into $\infty$-categories. This articulates a stratified generalization of the homotopy hypothesis proposed by Grothendieck. As such, each $\infty$-category defines a…

Algebraic Topology · Mathematics 2017-03-30 David Ayala , John Francis , Nick Rozenblyum

We confirm the quasi-projective case of Saito's conjecture, namely that the cohomological characteristic classes defined by Abbes and Saito can be computed in terms of the characteristic cycles. We construct a cohomological characteristic…

Algebraic Geometry · Mathematics 2025-02-18 Enlin Yang , Yigeng Zhao

We show that for quasi-compact quasi-separated schemes of finite dimension, the constructibility condition in real \'etale cohomology agrees with a notion of constructibility arising naturally from topology. As application we prove that the…

Algebraic Geometry · Mathematics 2022-01-04 Fangzhou Jin

In this paper we study the Witt groups of symmetric and anti-symmetric forms on perverse sheaves on a finite-dimensional topologically stratified space with even dimensional strata. We show that the Witt group has a canonical decomposition…

Algebraic Topology · Mathematics 2020-01-15 Jörg Schürmann , Jon Woolf

Let $X$ be a real analytic manifold endowed with a distance satisfying suitable properties and let $\mathbf{k}$ be a field. In [PS20], the authors construct a pseudo-distance on the derived category of sheaves of $\mathbf{k}$-modules on…

Algebraic Geometry · Mathematics 2021-11-03 Francois Petit , Pierre Schapira , Lukas Waas

We provide a general construction of induced $t$-structures, that generalizes standard $t$-structures for $\infty$-categories of sheaves. More precisely, given a presentable $\infty$-category $\mathcal{X}$ and a presentable stable…

Category Theory · Mathematics 2025-04-11 Peter J. Haine , Mauro Porta , Jean-Baptiste Teyssier