English
Related papers

Related papers: An approach to intersection theory on singular var…

200 papers

We study Poisson structures over singular varieties. In this purpose, we consider the Koszul complex associated to the equations of a complete intersection. This complex forms a differential graded algebra which is equivalent to the algebra…

Rings and Algebras · Mathematics 2007-05-23 Benoit Fresse

A homotopical treatment of intersection cohomology recently developed by Chataur-Saralegui-Tanr\'e associates a "perverse algebraic model" to every topological pseudomanifold, extending Sullivan's presentation of rational homotopy to…

Algebraic Topology · Mathematics 2016-03-31 David Chataur , Joana Cirici

We develop a generalization to non-Witt spaces of the intersection homology theory of Goresky-MacPherson. The second author has described the self-dual sheaves compatible with intersection homology, and the other authors have described a…

Geometric Topology · Mathematics 2013-08-20 Pierre Albin , Markus Banagl , Eric Leichtnam , Rafe Mazzeo , Paolo Piazza

This paper has two aims. The former is to give an introduction to our earlier work on the Hodge theory of algebraic maps and more generally to some of the main themes of the theory of perverse sheaves and to some of its geometric…

Algebraic Geometry · Mathematics 2007-05-23 Mark Andrea A. de Cataldo , Luca Migliorini

Let X be a pseudomanifold. In this text, we use a simplicial blow-up to define a cochain complex whose cohomology with coefficients in a field, is isomorphic to the intersection cohomology of X, introduced by M. Goresky and R. MacPherson.…

Algebraic Topology · Mathematics 2018-06-21 David Chataur , Martintxo Saralegi-Aranguren , Daniel Tanré

We study intersection theory and Chern classes of reflexive sheaves on normal varieties. In particular, we define generalization of Mumford's intersection theory on normal surfaces to higher dimensions. We also define and study the second…

Algebraic Geometry · Mathematics 2025-07-11 Adrian Langer

We show how to equip the cone complexes of toroidal embeddings with additional structure that allows to define a balancing condition for weighted subcomplexes. We then proceed to develop the foundations of an intersection theory on cone…

Algebraic Geometry · Mathematics 2018-02-07 Andreas Gross

Eilenberg-MacLane spaces, that classify the singular cohomology groups of topological spaces, admit natural constructions in the framework of simplicial sets. The existence of similar spaces for the intersection cohomology groups of a…

Algebraic Topology · Mathematics 2025-08-05 David Chataur , Daniel Tanré

For a holomorphic function on a complex manifold, we show that the vanishing cohomology of lower degree at a point is determined by that for the points near it, using the perversity of the vanishing cycle complex. We calculate it explicitly…

Algebraic Geometry · Mathematics 2007-05-23 Alexandru Dimca , Morihiko Saito

Numerical equivalence of algebraic cycles is defined abstractly by intersection numbers. Classically, for smooth complex proper toric varieties, the quotients by numerical equivalence with rational coefficients can be described…

Algebraic Geometry · Mathematics 2026-05-14 Ryota Mikami

We investigate the viability of defining an intersection product on algebraic cycles on a singular algebraic variety by pushing forward intersection products formed on a resolution of singularities. For varieties with resolutions having a…

Algebraic Geometry · Mathematics 2014-04-09 Joseph Ross

The aim of this paper is to study the behavior of Hodge-theoretic (intersection homology) genera and their associated characteristic classes under proper morphisms of complex algebraic varieties. We obtain formulae that relate (parametrized…

Algebraic Geometry · Mathematics 2012-04-03 Sylvain E. Cappell , Laurentiu G. Maxim , Julius L. Shaneson

For an arbitrary complex algebraic variety which is not necessarily pure dimensional, the intersection complex can be defined as the direct sum of the Deligne-Goresky-MacPherson intersection complexes of each irreducible component. We give…

Algebraic Geometry · Mathematics 2020-02-10 Ben Wu

Banagl's method of intersection spaces allows to modify certain types of stratified pseudomanifolds near the singular set in such a way that the rational Betti numbers of the modified spaces satisfy generalized Poincar\'{e} duality in…

Algebraic Topology · Mathematics 2020-04-14 Dominik Wrazidlo

We present a definition of intersection homology for real algebraic varieties that is analogous to Goresky and MacPherson's original definition of intersection homology for complex varieties.

Algebraic Geometry · Mathematics 2017-12-27 Clint McCrory , Adam Parusinski

For a pair (algebra, module) with equidimensional and isolated singularity we establish the existence of a versal henselian deformation. Obstruction theory in terms of an Andr\'e-Quillen cohomology for pairs is a central ingredient in the…

Commutative Algebra · Mathematics 2021-06-11 Runar Ile

A hypertoric variety is a quaternionic analogue of a toric variety. Just as the topology of toric varieties is closely related to the combinatorics of polytopes, the topology of hypertoric varieties interacts richly with the combinatorics…

Algebraic Geometry · Mathematics 2021-06-18 Nicholas Proudfoot , Ben Webster

These notes aim to give a first introduction to intersection cohomology and perverse sheaves with applications to representation theory or quantum groups in mind.

Representation Theory · Mathematics 2007-05-23 Konstanze Rietsch

Torsion sensitive intersection homology was introduced to unify several versions of Poincare duality for stratified spaces into a single theorem. This unified duality theorem holds with ground coefficients in an arbitrary PID and with no…

Geometric Topology · Mathematics 2023-09-27 Greg Friedman

This paper is an introduction to the use of perverse sheaves with positive characteristic coefficients in modular representation theory. In the first part, we survey results relating singularities in finite and affine Schubert varieties and…

Representation Theory · Mathematics 2014-10-07 Daniel Juteau , Carl Mautner , Geordie Williamson