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For two complex vector bundles admitting a homomorphism, whose singularity locates in the disjoint union of some odd--dimensional spheres, we give a formula to compute the relative Chern characteristic number of these two complex vector…

Differential Geometry · Mathematics 2017-10-26 Dexie Lin

There are some generalizations of the classical Eisenbud-Levine-Khimshashvili formula for the index of a singular point of an analytic vector field on $R^n$ for vector fields on singular varieties. We offer an alternative approach based on…

Algebraic Geometry · Mathematics 2016-09-07 Wolfgang Ebeling , Sabir M. Gusein-Zade

We study constraints on the Chern classes of a vector bundle on a singular variety. We use this constraint to study a variety which carries a Hodge cycle that are not a linear combination of Chern classes of vector bundles on it.

Algebraic Geometry · Mathematics 2013-04-02 Donu Arapura , Xi Chen , Su-Jeong Kang

This work has two complementary parts, in the first part we compute the local Euler obstruction of generic determinantal varieties and apply this result to compute the Chern--Schwartz--MacPherson class of such varieties. In the second part…

Algebraic Geometry · Mathematics 2017-11-08 Terence Gaffney , Nivaldo G. Grulha , Maria A. S. Ruas

In this work we study characteristic classes of possibly singular varieties embedded as a closed subvariety of a nonsingular variety. In special, we express the Schwartz-MacPherson class in terms of the $\mu$-class and Chern class of the…

Algebraic Geometry · Mathematics 2024-10-04 Antonio M. Ferreira , Fernando Lourenco

We consider manifolds with isolated singularities, i.e., topological spaces which are manifolds (say, $C^\infty$--) outside discrete subsets (sets of singular points). For (germs of) manifolds with, so called, cone--like singularities, a…

alg-geom · Mathematics 2007-05-23 Wolfgang Ebeling , Sabir M. Gusein-Zade

We formulate and prove a formula for transgressing characteristic forms in general associated bundles following a method of Chern. As applications, we derive D. Johnson's explicit formula for such general transgression and Chern's first…

Differential Geometry · Mathematics 2011-02-04 Zhaohu Nie

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

These notes form the next episode in a series of articles dedicated to a detailed proof of a cohomological index formula for transversally elliptic pseudo-differential operators and applications. The first two chapters are already available…

Differential Geometry · Mathematics 2008-01-21 Paul-Emile Paradan , Michèle Vergne

We study singular hermitian metrics on holomorphic vector bundles, following Berndtsson-P{\u{a}}un. Previous work by Raufi has shown that for such metrics, it is in general not possible to define the curvature as a current with measure…

Complex Variables · Mathematics 2018-01-16 Richard Lärkäng , Hossein Raufi , Jean Ruppenthal , Martin Sera

In this paper a formula is proved for the general degeneracy locus associated to an oriented quiver of type A_n. Given a finite sequence of vector bundles with maps between them, these loci are described by putting rank conditions on…

Algebraic Geometry · Mathematics 2009-10-31 Anders S. Buch , William Fulton

Combinatorial ideas are developed in this article to study Chern numbers on ample and numerically effective vector bundles. An effective lower bound for Chern numbers of ample vector bundles is established, which makes some progress towards…

Differential Geometry · Mathematics 2025-07-30 Ping Li

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

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

We relate the existence of Noether global conserved currents associated with locally variational field equations to existence of global solutions for a local variational problem generating global equations. Both can be characterized as the…

Mathematical Physics · Physics 2017-02-13 Marcella Palese , Ekkehart Winterroth

We give explicit MacPherson cycles for the Chern-MacPherson class of a closed affine algebraic variety $X$ and for any constructible function $\alpha$ with respect to a complex algebraic Whitney stratification of $X$. We define generalized…

Algebraic Geometry · Mathematics 2010-03-30 Joerg Schuermann , Mihai Tibar

We derive a formula for the Chern classes of the bundles of conformal blocks on \bar{M}_{0,n} associated to simple finite dimensional Lie algebras and explore its consequences in more detail for sl_2 and in general for level 1. We also give…

Algebraic Geometry · Mathematics 2011-05-10 Najmuddin Fakhruddin

We consider the geometric quantisation of Chern--Simons theory for closed genus-one surfaces and semisimple complex groups. First we introduce the natural complexified analogue of the Hitchin connection in K\"{a}hler quantisation, with…

Quantum Algebra · Mathematics 2023-04-27 Jørgen Ellegaard Andersen , Alessandro Malusà , Gabriele Rembado

We consider closed manifolds that admit a metric locally isometric to a product of symmetric planes. For such manifolds, we prove that the Euler characteristic is an obstruction to the existence of flat structures, confirming an old…

Geometric Topology · Mathematics 2009-05-23 Michelle Bucher , Tsachik Gelander

We define integral geometric analogues of the Chern classes for real vector bundle on a smooth real variety. More precisely, we define the Chern densities of a real bundle. These densities are analogues of the Chern forms of a complex…

Algebraic Geometry · Mathematics 2024-04-12 Boris Kazarnovskii