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Related papers: An introduction to perverse sheaves

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We study perverse sheaves of categories their connections to classical algebraic geometry. We show how perverse sheaves of categories encode naturally derived categories of coherent sheaves on $\mathbb{P}^1$ bundles, semiorthogonal…

Algebraic Geometry · Mathematics 2019-07-01 Andrew Harder , Ludmil Katzarkov

We study the cohomology theory of sheaf complexes for open embeddings of topological spaces and related subjects. The theory is situated in the intersection of the general Cech theory and the theory of derived categories. That is to say, on…

Algebraic Topology · Mathematics 2018-10-16 Tatsuo Suwa

We define a quantum analogue of the Grothendieck ring of finite dimensional modules of a quantum affine algebra of simply laced type. The construction is based on perverse sheaves on a variety related to quivers. We get also a new geometric…

Quantum Algebra · Mathematics 2007-05-23 Michela Varagnolo , Eric Vasserot

We propose the notion of perverse coherent sheaves for symplectic singularities and study its properties. In particular, it gives a basis of simple objects in the Grothendieck group of Poisson sheaves. We show that perverse coherent bases…

Representation Theory · Mathematics 2025-10-28 Ilya Dumanski

Lecture notes. Introduction to the cohomology of algebras, Lie algebras, Lie bialgebras and quantum groups. Contains a new derivation of the classification of classical r-matrices in terms of deformation cohomology, and a calculation of the…

q-alg · Mathematics 2014-05-27 Christian Fronsdal

This text is an introduction to equivariant cohomology, a classical tool for topological transformation groups, and to equivariant intersection theory, a much more recent topic initiated by D. Edidin and W. Graham. It is based on lectures…

Algebraic Geometry · Mathematics 2007-05-23 Michel Brion

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

A brief synopsis of recent conceptions and results, the current status and future outlook of our research program of applying sheaf and topos-theoretic ideas to quantum gravity and quantum logic is presented.

General Relativity and Quantum Cosmology · Physics 2007-05-23 Ioannis Raptis

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 geometric representation theory, one often wishes to describe representations realized on spaces of invariant functions as trace functions of equivariant perverse sheaves. In the case of principal series representations of a connected…

Algebraic Geometry · Mathematics 2011-07-29 Masoud Kamgarpour , Travis Schedler

Given certain intersection cohomology sheaves on a projective variety with a torus action, we relate the cohomology groups of their tensor product to the cohomology groups of the individual sheaves. We also prove a similar result in the…

Representation Theory · Mathematics 2016-01-20 Asilata Bapat

This is the second in a series of papers. Here we develop here an intersection theory for manifolds equipped with an action of a finite group. As in our previous paper, our approach will be homotopy theoretic, enabling us to circumvent the…

Algebraic Topology · Mathematics 2009-01-23 John R. Klein , Bruce Williams

The theory of intersection spaces assigns cell complexes to certain stratified topological pseudomanifolds depending on a perversity function in the sense of intersection homology. The main property of the intersection spaces is Poincar\'e…

Algebraic Topology · Mathematics 2018-12-03 J. Timo Essig

In this article we address the length of perverse sheaves arising as direct images of rank one local systems on complements of hyperplane arrangements. In the case of a cone over an essential line arrangement with at most triple points, we…

Algebraic Topology · Mathematics 2019-09-10 Nero Budur , Yongqiang Liu

This paper introduces the idea of pseudo-group. Applications of pseudo-groups in Group Theory and Symmetry Breaking in Particle Physics and Cosmology are considered.

High Energy Physics - Theory · Physics 2007-05-23 S. C. Woon

We present the construction and properties of a self-dual perverse sheaf S_0 whose cohomology fulfills some of the requirements of String theory as outlined by T. Hubsch in hep-th/9612075. The construction of this S_0 utilizes techniques…

Algebraic Topology · Mathematics 2026-03-26 Abdul Rahman

Let $X$ be any subanalytic compact pseudomanifold. We show a De Rham theorem for $L^\infty$ forms. We prove that the cohomology of $L^\infty$ forms is isomorphic to intersection cohomology in the maximal perversity.

Algebraic Geometry · Mathematics 2012-07-09 Guillaume Valette

We develop a theory of sheaves and cohomology on the category of proper modulus pairs. This complements [KMSY21], where a theory of sheaves and cohomology on the category of non-proper modulus pairs has been developed.

Algebraic Geometry · Mathematics 2024-04-17 Bruno Kahn , Hiroyasu Miyazaki , Shuji Saito , Takao Yamazaki

This article is an expository account of the theory of twisted commutative algebras, which simply put, can be thought of as a theory for handling commutative algebras with large groups of linear symmetries. Examples include the coordinate…

Commutative Algebra · Mathematics 2012-09-25 Steven V Sam , Andrew Snowden

We give a geometric construction of tilting perverse sheaves using stratified Morse theory, torus actions, and nearby cycles.

Representation Theory · Mathematics 2007-05-23 David Nadler