English
Related papers

Related papers: Exact functors on perverse coherent sheaves

200 papers

We introduce a singular chain intersection homology theory which generalizes that of King and which agrees with the Deligne sheaf intersection homology of Goresky and MacPherson on any topological stratified pseudomanifold, compact or not,…

Geometric Topology · Mathematics 2011-03-31 Greg Friedman

Chuang and Rouquier describe an action by perverse equivalences on the set of bases of a triangulated category of Calabi-Yau dimension $-1$. We develop an analogue of their theory for Calabi-Yau categories of dimension $w<0$ and show it is…

Representation Theory · Mathematics 2020-01-03 Jeremy Brightbill

In this paper, which is mostly a research announcement, we give a new algebraic construction of knot contact homology in the sense of L. Ng [Ng05a]. For a link $L$ in $ {\mathbb R}^3 $, we define a differential graded (DG) $k$-category $…

Algebraic Topology · Mathematics 2016-11-11 Yuri Berest , Alimjon Eshmatov , Wai-kit Yeung

The graded coherent sheaf $\alpha_X^\bullet$ constructed in [B.18] for any reduced pure dimensional complex space $X$ is stable by exterior product but not by the de Rham differential. We construct here a new graded coherent sheaf…

Algebraic Geometry · Mathematics 2020-03-06 Daniel Barlet

We show that the cohomology table of any coherent sheaf on projective space is a convergent--but possibly infinite--sum of positive real multiples of the cohomology tables of what we call supernatural sheaves.

Algebraic Geometry · Mathematics 2009-02-11 David Eisenbud , Frank-Olaf Schreyer

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

We study the categories $\mathrm{Perv}_{\mathrm{thin}}$ and $\mathrm{Perv}_{\mathrm{thick}}$ of Iwahori-equivariant perverse sheaves on the thin and thick affine flag varieties associated to a split reductive group $G$. An earlier work of…

Representation Theory · Mathematics 2026-04-06 Roman Bezrukavnikov , Calder Morton-Ferguson

Using techniques of [BKV], we construct a perverse t-structure on the infinity-category of l-adic LG-equivariant sheaves on the regular-semisimple bounded locus of the loop group LG and prove that the derived $\tau$-coinvariants of affine…

Algebraic Geometry · Mathematics 2025-06-25 Alexis Bouthier , David Kazhdan , Yakov Varshavsky

We prove estimates for the Betti numbers of constructible sheaves in characteristic p>0 depending only on their rank, stratification and wild ramification. In particular, given a smooth proper variety of dimension n over an algebraically…

Algebraic Geometry · Mathematics 2025-02-18 Haoyu Hu , Jean-Baptiste Teyssier

In this note, we consider perverse sheaves on the nilpotent cone. We prove orthogonality relations for the equivariant category of sheaves on the nilpotent cone in a method similar to Lusztig's for character sheaves. We also consider…

Representation Theory · Mathematics 2016-11-07 Laura Rider , Amber Russell

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 H be an arrangement of real hyperplanes in R^n. The complexification of H defines a natural stratification of C^n. We denote by Perv(C^n, H) the category of perverse sheaves on C^n smooth with respect to this stratification. We give a…

Algebraic Topology · Mathematics 2015-02-04 Mikhail Kapranov , Vadim Schechtman

We develop the notion of singular support of a coherent sheaf on a quasi-smooth DG scheme or stack and use it to formulate the Geometric Langlands Conjecture.

Algebraic Geometry · Mathematics 2014-11-04 Dima Arinkin , Dennis Gaitsgory

We study intersections of complex Lagrangian in complex symplectic manifolds, proving two main results. First, we construct global canonical perverse sheaves on complex Lagrangian intersections in complex symplectic manifolds for any pair…

Algebraic Geometry · Mathematics 2014-04-07 Vittoria Bussi

We consider birational projective contractions f:X -> Y from a smooth symplectic variety X over the complex numbers. We first show that exceptional rational curves on X deform in a family of dimension at least 2n-2. Then we show that these…

Algebraic Geometry · Mathematics 2007-05-23 Jan Wierzba

We prove a criterion for determining whether the normalization of a complex analytic space on which the constant sheaf is perverse is a rational homology manifold, using a perverse sheaf known as the multiple-point complex. This perverse…

Algebraic Geometry · Mathematics 2018-08-13 Brian Hepler

We develop a unified approach for identifying spaces of stability conditions of triangulated categories arising from weighted marked surfaces with moduli spaces of quadratic differentials. This approach is based on the notion of a perverse…

Representation Theory · Mathematics 2024-06-26 Merlin Christ , Fabian Haiden , Yu Qiu

We denote by Conc(A) the semilattice of all finitely generated congruences of an (universal) algebra A, and we define Conc(V) as the class of all isomorphic copies of all Conc(A), for A in V, for any variety V of algebras. Let V and W be…

Logic · Mathematics 2014-03-24 Pierre Gillibert

We define and study an analogue of Category O in the context of Kazhdan and Laumon's gluing construction for perverse sheaves on the basic affine space. We explicitly describe the simple objects in this category, and we show its linearized…

Representation Theory · Mathematics 2025-08-26 Calder Morton-Ferguson

We give a short and self-contained proof of the Decomposition Theorem for the non-small resolution of a Special Schubert variety. We also provide an explicit description of the perverse cohomology sheaves. As a by-product of our approach,…

Algebraic Geometry · Mathematics 2019-10-28 Davide Franco