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Related papers: Chern classes for singular hypersurfaces

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For a complex variety with a torus action we propose a new method of computing Chern-Schwartz-MacPherson classes. The method does not apply resolution of singularities. It is based on Localization Theorem in equivariant cohomology.

Algebraic Geometry · Mathematics 2012-06-07 Andrzej Weber

Since Chern and Grothendieck, Chern's characteristic class theory has made significant progress. In particular with regard to the classes of singular varieties. Conjectured by Grothendieck and Deligne and demonstrated by MacPherson, Chern…

Algebraic Geometry · Mathematics 2025-02-12 Jean-Paul Brasselet , Tadeusz Mostowski , Thuy Nguyen Thi Bich

Homology Hirzebruch characteristic classes for singular varieties have been recently defined by Brasselet-Schuermann-Yokura as an attempt to unify previously known characteristic class theories for singular spaces (e.g., MacPherson-Chern…

Algebraic Geometry · Mathematics 2016-05-24 Sylvain E. Cappell , Laurentiu Maxim , Joerg Schuermann , Julius L. Shaneson

In this note we clarify the relevance of ``connections up to homotopy'' to the theory of characteristic classes. We have already remarked \cite{Crai} that such connections up to homotopy can be used to compute the classical Chern…

Differential Geometry · Mathematics 2007-05-23 Marius Crainic

The purpose of this short note is to prove a formula for the Chern-Mather classes of a toric variety in terms of its orbits and the local Euler obstructions at general points of each orbit (Theorem 2). We use the general definition of the…

Algebraic Geometry · Mathematics 2016-04-12 Ragni Piene

We enumerate complex algebraic hypersurfaces in $P^n$, of a given (high) degree with one singular point of a given singularity type. Our approach is to compute the (co)homology classes of the corresponding equi-singular strata in the…

Algebraic Geometry · Mathematics 2014-02-26 Dmitry Kerner

We give explicit formulas for the Chern-Schwartz-MacPherson classes of all Schubert varieties in the Grassmannian of $d$-planes in a vector space, and conjecture that these classes are effective. We prove this is the case for (very) small…

Algebraic Geometry · Mathematics 2012-04-11 Paolo Aluffi , Leonardo Constantin Mihalcea

Let $K$ be an algebraically closed field of characteristic $0$. For $m\geq n$, we define $\tau_{m,n,k}$ to be the set of $m\times n$ matrices over $K$ with kernel dimension $\geq k$. This is a projective subvariety of $\bbP^{mn-1}$, and is…

Algebraic Geometry · Mathematics 2017-10-24 Xiping Zhang

The Chern class of the sheaf of logarithmic derivations along a simple normal crossing divisor equals the Chern-Schwartz-MacPherson class of the complement of the divisor. We extend this equality to more general divisors, which are locally…

Algebraic Geometry · Mathematics 2013-03-04 Paolo Aluffi

We define and study the secondary Chern-Euler class for a general submanifold of a Riemannian manifold. Using this class, we define and study index for a vector field with non-isolated singularities on a submanifold. As an application, our…

Differential Geometry · Mathematics 2009-07-14 Zhaohu Nie

The aim of this note is to point out that Chern characters can be computed using curvatures o ``super-connections up to homotopy'. We also present an application to the vanishing theorem for Lie algebroids which is at the origin of new…

Differential Geometry · Mathematics 2007-05-23 Marius Crainic

We offer a short proof of Connes' Hochschild class of the Chern character formula for non-unital semifinite spectral triples. The proof is simple due to its reliance on the authors' extensive work on a refined version of the local index…

K-Theory and Homology · Mathematics 2018-05-02 Alan L. Carey , A. Rennie

We give a general formula for the defect appearing in the Verdier-type Riemann-Roch formula for Chern-Schwartz-MacPherson classes in the case of a regular embedding. Our proof of this formula uses the constructible function version of…

Algebraic Geometry · Mathematics 2007-05-23 Joerg Schuermann

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 introduce a notion of integration on the category of proper birational maps to a given variety $X$, with value in an associated Chow group. Applications include new birational invariants; comparison results for Chern classes and numbers…

Algebraic Geometry · Mathematics 2012-04-10 Paolo Aluffi

We introduce a cohomology, called extendable cohomology, for abstract complex singular varieties based on suitable differential forms. Beside a study of the general properties of such a cohomology, we show that, given a complex vector…

Complex Variables · Mathematics 2008-12-04 Carlo Perrone

In this paper, I construct Chern classes in the rigid cohomology of P. Berthelot. We start by constructing Chern classes for proper varieties. To prove all the properties we have to reinterpret the construction in a crystalline way. Then we…

Algebraic Geometry · Mathematics 2007-05-23 Petrequin Denis

Let $V$ be a possibly singular scheme-theoretic complete intersection subscheme of $\mathbb{P}^n$ over an algebraically closed field of characteristic zero. Using a recent result of Fullwood ("On Milnor classes via invariants of singular…

Algebraic Geometry · Mathematics 2017-11-15 Martin Helmer

In this note we will review the most important results and questions related to Chern conjecture and isoparametric hypersurfaces, as well as their interactions and applications to various aspects in mathematics.

History and Overview · Mathematics 2012-03-05 Jianquan Ge , Zizhou Tang

There are several ways to generalize characteristic classes for singular algebraic varieties. The simplest ones to describe are Chern-Mather classes obtained by Nash blow up. They serve as an ingredient to construct…

alg-geom · Mathematics 2007-05-23 Jean-Paul Brasselet , Andrzej Weber