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Related papers: An equivariant version of the Euler obstruction

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We describe Universal Coefficient Theorems for the equivariant Kasparov theory for C*-algebras with an action of the group of integers or over a unique path space, using KK-valued invariants. We compare the resulting classification up to…

K-Theory and Homology · Mathematics 2020-11-04 Ralf Meyer

For a G-invariant holomorphic 1-form with an isolated singular point on a germ of a complex-analytic G-variety with an isolated singular point (G is a finite group) one has notions of the equivariant homological index and of the (reduced)…

Algebraic Geometry · Mathematics 2017-01-10 Sabir M. Gusein-Zade , Firuza I. Mamedova

If two G-manifolds are G-cobordant then characteristic numbers corresponding to the fixed point sets (submanifolds) of subgroups of G and to normal bundles to these sets coincide. We construct two analogues of these characteristic numbers…

Algebraic Geometry · Mathematics 2014-06-18 Wolfgang Ebeling , Sabir M. Gusein-Zade

Let $V, W$ be finite-dimensional orthogonal representations of a finite group $G$. The equivariant degree with values in the Burnside ring of $G$ has been studied extensively by many authors. We present a short proof of the degree product…

Algebraic Topology · Mathematics 2019-10-29 Piotr Bartłomiejczyk , Bartosz Kamedulski , Piotr Nowak-Przygodzki

After we have given a survey on the Burnside ring of a finite group, we discuss and analyze various extensions of this notion to infinite (discrete) groups. The first three are the finite-G-set-version, the inverse-limit-version and the…

Algebraic Topology · Mathematics 2007-05-23 Wolfgang Lueck

In this paper we study an integral invariant which obstructs the existence on a compact complex manifold of a volume form with the determinant of its Ricci form proportional to itself, in particular obstructs the existence of a…

Differential Geometry · Mathematics 2020-07-30 Akito Futaki , Kota Hattori , Liviu Ornea

In this paper, we prove that the orbit space B and the Euler class of an action of the circle S^1 on X determine both the equivariant intersection cohomology of the pseudomanifold X and its localization. We also construct a spectral…

Algebraic Topology · Mathematics 2014-04-04 Jose Ignacio Royo Prieto , Martintxo Saralegi-Aranguren

We introduce the degree and local degree in equivariant motivic homotopy theory for the purpose of studying equivariant enumerative problems over general fields. Given a finite, tame group scheme $G$ over a field $k$ and an equivariant…

Algebraic Geometry · Mathematics 2026-04-02 Candace Bethea , Charanya Ravi

Applying a local Gauss-Bonnet formula for closed subanalytic sets to the complex analytic case, we obtain characterizations of the Euler obstruction of a complex analytic germ in terms of the Lipschitz-Killing curvatures and the Chern forms…

Algebraic Geometry · Mathematics 2014-05-26 Nicolas Dutertre

In this paper, we investigate the local Euler obstruction and the relative local Euler obstruction in terms of constructible complexes of sheaves, characteristic cycles, and vanishing cycles. The fundamental tool that we use is the notion…

Algebraic Geometry · Mathematics 2017-05-03 David B. Massey

We determine the relation between the local Euler obstruction $Eu_f$ of a holomorphic function $f$ and different generalizations of the Milnor number for functions on singular spaces.

Complex Variables · Mathematics 2007-05-23 Jose Seade , Mihai Tibar , Alberto Verjovsky

For a compact Lie group G, we use G-equivariant Poincar\'e duality for ordinary RO(G)-graded homology to define an equivariant intersection product, the dual of the equivariant cup product. Using this, we give a homological construction of…

Algebraic Topology · Mathematics 2013-07-23 Philipp Wruck

For a proper action by a locally compact group $G$ on a manifold $M$ with a $G$-equivariant Spin-structure, we obtain obstructions to the existence of complete $G$-invariant Riemannian metrics with uniformly positive scalar curvature. We…

Differential Geometry · Mathematics 2024-09-02 Hao Guo , Peter Hochs , Varghese Mathai

This article is about 1-forms on complex analytic varieties and it is particularly relevant when the variety has non-isolated singularities. We first show how the radial extension technique of M.-H. Schwartz can be adapted to 1-forms,…

Algebraic Geometry · Mathematics 2007-05-23 J. -P. Brasselet , J. Seade , T. Suwa

The Euler obstruction of a function can be viewed as a generalization of the Milnor number for functions defined on singular spaces. In this work, using the Euler obstruction of a function, we give a version of the L\^e-Greuel formula for…

Algebraic Geometry · Mathematics 2013-11-11 Nicolas Dutertre , Nivaldo G. Grulha

This is a continuation of the authors' previous work [math.AT/9910001] on classification of equivariant complex vector bundles over a circle. In this paper we classify equivariant real vector bundles over a circle with a compact Lie group…

Algebraic Topology · Mathematics 2023-10-31 Jin-Hwan Cho , Sung Sook Kim , Mikiya Masuda , Dong Youp Suh

Let $G$ be an algebraic group and let $X$ be a smooth $G$-variety with two orbits: an open orbit and a a closed orbit of codimension $1$. We give an algebraic description of the category of $G$-equivariant vector bundles on $X$ under a mild…

Algebraic Geometry · Mathematics 2022-02-22 Lucas Mason-Brown , James Tao

We explore some of the special features with respect to Bredon cohomology of groups having all its finite subgroups either nilpotent or p-groups or cyclic p-groups. We get some results on dimensions and also a formula for the equivariant…

Group Theory · Mathematics 2013-03-13 Conchita Martínez-Pérez

Integrals of the Pfaffian form over the nonsingular part of a projective variety compute information closely related to the Mather-Chern class of the variety and to other invariants such as the local Euler obstruction along strata of its…

Algebraic Geometry · Mathematics 2021-02-03 Paolo Aluffi , Mark Goresky

In a previous paper, the authors defined an equivariant version of the so-called Saito duality between the monodromy zeta functions as a sort of Fourier transform between the Burnside rings of an abelian group and of its group of…

Algebraic Geometry · Mathematics 2015-06-19 Wolfgang Ebeling , Sabir M. Gusein-Zade