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We consider a class of relative $n$-Calabi--Yau dg-algebras, referred to as relative Ginzburg algebras, associated with marked surfaces equipped with a decomposition into $n$-gons ($n$-angulation). We relate their derived categories to the…

Representation Theory · Mathematics 2023-07-24 Merlin Christ

We define a new perverse t-exact pullback operation on derived categories of constructible sheaves which generalizes most perverse t-exact functors in sheaf theory, such as microlocalization, the Fourier-Sato transform and vanishing cycles.…

Algebraic Geometry · Mathematics 2025-10-21 Adeel A. Khan , Tasuki Kinjo , Hyeonjun Park , Pavel Safronov

We consider non-commutative deformations of sheaves on algebraic varieties. We develop some tools to determine parameter algebras of versal non-commutative deformations for partial simple collections and the structure sheaves of smooth…

Algebraic Geometry · Mathematics 2021-08-31 Yujiro Kawamata

We relate Nakajima Quiver Varieties (or, rather, their multiplicative version) with moduli spaces of perverse sheaves. More precisely, we consider a generalization of the concept of perverse sheaves: microlocal sheaves on a nodal curve X.…

Symplectic Geometry · Mathematics 2015-06-30 Roman Bezrukavnikov , Mikhail Kapranov

Let X be a scheme of finite type over a Noetherian base scheme S admitting a dualizing complex, and let U be an open subset whose complement has codimension at least 2. We extend the Deligne-Bezrukavnikov theory of perverse coherent sheaves…

Representation Theory · Mathematics 2017-01-03 Pramod N. Achar , Daniel S. Sage

Inspired by symplectic geometry and a microlocal characterizations of perverse (constructible) sheaves we consider an alternative definition of perverse coherent sheaves. We show that a coherent sheaf is perverse if and only if…

Algebraic Geometry · Mathematics 2015-09-30 Clemens Koppensteiner

The proposed physical duality known as 3d mirror symmetry relates the geometries of dual pairs of holomorphic symplectic stacks. It has served in recent years as a guiding principle for developments in representation theory. However, due to…

Representation Theory · Mathematics 2023-05-30 Benjamin Gammage , Justin Hilburn , Aaron Mazel-Gee

A class of perverse sheaves on framed representation varieties of the Jordan quiver is defined. Its relationship with product of symmetric groups, tensor product of Schur algebras, and tensor product of Fock spaces are addressed.

Representation Theory · Mathematics 2012-09-18 Yiqiang Li

Perverse schobers can be used to describe Fukaya categories but are hard to axiomatize and construct. In this paper, we give an explicit construction of a perverse schober intended to accurately describe the Fukaya category of the…

Representation Theory · Mathematics 2025-09-01 Jasper van de Kreeke

We describe diagrammatically a positively graded Koszul algebra \mathbb{D}_k such that the category of finite dimensional \mathbb{D}_k-modules is equivalent to the category of perverse sheaves on the isotropic Grassmannian of type D_k…

Representation Theory · Mathematics 2013-06-19 Michael Ehrig , Catharina Stroppel

In the strict semi stable reduction situation, we describe the various filtrations of the perverse sheaf of nearby cycles in terms of irreducible perverse sheaves together with the action of the monodromy operator. We then study the…

Algebraic Geometry · Mathematics 2026-01-06 Pascal Boyer

This is not standard in the sense that we understand a Springer map to be a collapsing of homogeneous bundles. Apart from that we use mostly techniques from Chriss and Ginzbergs book but we work in the equivariant derived category of…

Representation Theory · Mathematics 2013-08-14 Julia Sauter

The geometric Satake isomorphism is an equivalence between the categories of spherical perverse sheaves on affine Grassmanian and the category of representations of the Langlands dual group. We provide a similar description for derived…

Representation Theory · Mathematics 2020-02-13 Sergey Arkhipov , Roman Bezrukavnikov

Let H be an arrangement of hyperplanes in R^n and Perv(C^n,H) be the category of perverse sheaves on C^n smooth with respect to the stratification given by complexified flats of H. We give a description of Perv(C^n,H) in terms of "matrix…

Algebraic Topology · Mathematics 2019-10-07 Mikhail Kapranov , Vadim Schechtman

We introduce a class of perverse sheaves on a partial flag manifold of a connected reductive group G defined over a finite field which are equivariant under the action of the group of rational points of G. The definition of this class is…

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

An intrinsic construction of the tensor category of finite dimensional representations of the Langlands dual group of G in terms of a tensor category of perverse sheaves on the loop group, LG, is given. The construction is applied to the…

alg-geom · Mathematics 2008-02-03 Victor Ginzburg

We give an explicit construction of the stack of microlocal perverse sheaves on the projective cotangent bundle of a complex manifold. Microlocal perverse sheaves will be represented as complexes of analytic ind-sheaves which have recently…

Algebraic Geometry · Mathematics 2007-05-23 Ingo Waschkies

Perverse schober defined by Kapranov--Schechtman is a categorification of the notion of perverse sheaf. In their definition, a key ingredient is certain purity property of perverse sheaves. In this short note, we attempt to describe a real…

Algebraic Geometry · Mathematics 2019-02-19 Tatsuki Kuwagaki

We briefly introduce the theory of perverse sheaves with special attention to the topological situation where strata can have odd dimension. This is part of a project to use perverse sheaves on the topological reductive Borel-Serre…

Algebraic Geometry · Mathematics 2016-12-06 Leslie Saper

Perverse-Hodge complexes are objects in the derived category of coherent sheaves obtained from Hodge modules associated with Saito's decomposition theorem. We study perverse-Hodge complexes for Lagrangian fibrations and propose a symmetry…

Algebraic Geometry · Mathematics 2026-05-27 Junliang Shen , Qizheng Yin