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Related papers: Equivariant indices of vector fields and 1-forms

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Given a linear action of a group $G$ on a $K$-vector space $V$, we consider the invariant ring $K[V \oplus V^*]^G$, where $V^*$ is the dual space. We are particularly interested in the case where $V =\gfq^n$ and $G$ is the group $U_n$ of…

Commutative Algebra · Mathematics 2011-04-05 Cédric Bonnafé , G. Kemper

We construct a degree-type otopy invariant for equivariant gradient local maps in the case of a real finite dimensional orthogonal representation of a compact Lie group. We prove that the invariant establishes a bijection between the set of…

Algebraic Topology · Mathematics 2018-01-09 Piotr Bartłomiejczyk , Piotr Nowak-Przygodzki

Let G be a finite group acting on a finite dimensional real vector space V. We denote by P(V) the projective space associated to V. In this paper we compute in a very explicit way the rank of the equivariant complex K-theory of V and P(V),…

K-Theory and Homology · Mathematics 2007-05-23 Max Karoubi

This paper introduces and studies the higher-order group inverse in a ring. We extend known properties of the higher-order group inverse from complex matrices to elements of a ring and, in the process, derive new results. We further…

Rings and Algebras · Mathematics 2026-02-17 Liu Dayong , Chen Huanyin

We describe the multiplicative structures that arise on categories of equivariant modules over certain equivariant commutative ring spectra. Building on our previous work on N-infinity ring spectra, we construct categories of equivariant…

Algebraic Topology · Mathematics 2019-08-07 Andrew J. Blumberg , Michael A. Hill

In this paper, we study $G$-equivariant tensor categories for a finite group $G$. These categories were introduced by Turaev under the name of $G$-crossed categories; the motivating example of such a category is the category of twisted…

Quantum Algebra · Mathematics 2007-05-23 Alexander Kirillov

In this work the equivariant signature of a manifold with proper action of a discrete group is defined as an invariant of equivariant bordisms. It is shown that the computation of this signature can be reduced to its computation on fixed…

Algebraic Topology · Mathematics 2011-12-12 A. S. Mishchenko , Quitzeh Morales Meléndez

We introduce bilinear forms in a flag in a complete intersection local $\mathbb R$-algebra of dimension 0, related to the Eisenbud-Levine, Khimshiashvili bilinear form. We give a variational interpretation of these forms in terms of…

Algebraic Geometry · Mathematics 2008-01-10 L. Giraldo , X. Gomez-Mont , P. Mardesic

Every finite local principal ideal ring is the homomorphic image of a discrete valuation ring of a number field, and is determined by five invariants. We present an action of a group, non-commutative in general, on the set of Eisenstein…

Commutative Algebra · Mathematics 2025-04-03 Matthé van der Lee

A. Vistoli proved a decomposition theorem for the rational equivariant algebraic K-theory of a variety under the action of a finite group $G$. We generalize his result to more general algebraic (co)homology theories having the Mackey…

Algebraic Geometry · Mathematics 2025-05-21 Francesco Sala

We define the equivariant Chern-Schwartz-MacPherson class of a possibly singular algebraic variety with a group action over the complex number field (or a field of characteristic 0). In fact, we construct a natural transformation from the…

Algebraic Geometry · Mathematics 2009-11-10 Toru Ohmoto

We develop a formula for the equivariant index of a twisted Dirac operator on a compact globally hyperbolic spacetime with timelike boundary on which a group acts isometrically, subject to APS boundary conditions. The formula is the same as…

Differential Geometry · Mathematics 2026-02-19 Onirban Islam , Lennart Ronge

Equiangular tight frames (ETFs) are configurations of vectors which are optimally geometrically spread apart and provide resolutions of the identity. Many known constructions of ETFs are group covariant, meaning they result from the action…

Group Theory · Mathematics 2019-05-22 Emily J. King

In this note several computations of equivariant cohomology groups are performed. For the compactly supported equivariant cohomology, the notion of infinitesimal index developed in arXiv:1003.3525, allows to describe these groups in terms…

Differential Geometry · Mathematics 2015-03-17 Corrado De Concini , Claudio Procesi , Michele Vergne

This paper establishes a connection between equivariant ring spectra and Witt vectors in the sense of Dress and Siebeneicher. Given a commutative ringspectrum T in the highly structured sense, that is, an E-infinity-ringspectrum, with…

Algebraic Topology · Mathematics 2007-05-23 Morten Brun

We introduce a scissors congruence $K$-theory spectrum which lifts the equivariant scissors congruence groups for compact $G$-manifolds with boundary, and we show that on $\pi_0$ this is the source of a spectrum level lift of the Burnside…

Algebraic Topology · Mathematics 2025-08-18 Mona Merling , Ming Ng , Julia Semikina , Alba Sendón Blanco , Lucas Williams

In this note we present a combinatorial link invariant that underlies some recent stable homotopy refinements of Khovanov homology of links. The invariant takes the form of a functor between two combinatorial 2-categories, modulo a notion…

Geometric Topology · Mathematics 2021-11-16 Tyler Lawson , Robert Lipshitz , Sucharit Sarkar

We extend in several directions invariant theory results of Chevalley, Shephard and Todd, Mitchell and Springer. Their results compare the group algebra for a finite reflection group with its coinvariant algebra, and compare a group…

Commutative Algebra · Mathematics 2014-02-26 Abraham Broer , Victor Reiner , Larry Smith , Peter Webb

For any finite reflection group $W$ on $\mathbb{R}^{N}$ and any irreducible $W$-module $V$ there is a space of polynomials on $\mathbb{R}^{N}$ with values in $V$. There are Dunkl operators parametrized by a multiplicity function, that is,…

Representation Theory · Mathematics 2018-09-07 Charles F. Dunkl

In this expository article, we consider first order elliptic differential operators acting on smooth vector bundles over compact manifolds, and certain invariants derived from the analysis of these operators, namely the eta invariant} and…

Differential Geometry · Mathematics 2019-08-15 Jochen Brüning , Ken Richardson
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