English
Related papers

Related papers: Good objects in the equivariant world

200 papers

As a practical foundation for a homotopy theory of abstract spacetime, we extend a category of certain compact partially ordered spaces to a convenient category of locally preordered spaces. In particular, we show that our new category is…

Algebraic Topology · Mathematics 2008-12-06 Sanjeevi Krishnan

Local cohomology functors are constructed for the category of cohomological functors on an essentially small triangulated category T equipped with an action of a commutative noetherian ring. This is used to establish a local-global…

Category Theory · Mathematics 2019-02-20 Dave Benson , Srikanth B. Iyengar , Henning Krause

We present a new geometric interpretation of equivariant cohomology in which one replaces a smooth, complex $G$-variety $X$ by its associated arc space $J_{\infty} X$, with its induced $G$-action. This not only allows us to obtain geometric…

Algebraic Geometry · Mathematics 2014-02-18 Dave Anderson , Alan Stapledon

We consider the existence of bibundles, in other words locally trivial principal $G$ spaces with commuting left and right $G$ actions. We show that their existence is closely related to the structure of the group $\Out(G)$ of outer…

Differential Geometry · Mathematics 2013-02-25 Michael Murray , David Michael Roberts , Danny Stevenson

We study the fixed points of the universal G-equivariant n-dimensional complex vector bundle and obtain a decomposition formula in terms of twisted equivariant universal complex vector bundles of smaller dimension. We use this decomposition…

Algebraic Topology · Mathematics 2018-12-19 Andrés Angel , José Manuel Gómez , Bernardo Uribe

We give a general framework of equivariant model category theory. Our groups G, called Hopf groups, are suitably defined group objects in any well-behaved symmetric monoidal category V. For any V, a discrete group G gives a Hopf group,…

Algebraic Topology · Mathematics 2017-09-01 Bertrand Guillou , J. P. May , Jonathan Rubin

We formulate and prove an index theorem for loop spaces of compact manifolds in the framework of $KK$-theory. It is a strong candidate for the noncommutative geometrical definition (or the analytic counterpart) of the Witten genus. In order…

K-Theory and Homology · Mathematics 2022-08-26 Doman Takata

For the quiver Hecke algebra $R$, let $R\hbox{-gmod}$ be the category of finite-dimensional graded $R$-modules, and let $\widetilde{R\hbox{-gmod}[w]}$ be the localization of $R\hbox{-gmod}$. Kashiwara and the second author showed the set of…

Representation Theory · Mathematics 2025-11-14 Koh Matsuura , Toshiki Nakashima

We introduce the notion of the \emph{equivariant covering type} of a space $X$ on which a finite group $G$ acts, and study its properties. The equivariant covering type measures the size of $G$-equivariant good covers of $X$ and is thus an…

Algebraic Topology · Mathematics 2024-11-27 Dejan Govc , Waclaw Marzantowicz , Petar Pavesic

Using the language and terminology of relative homological algebra, in particular that of derived functors, we introduce equivariant cohomology over a general Lie-Rinehart algebra and equivariant de Rham cohomology over a locally trivial…

Differential Geometry · Mathematics 2013-03-12 Johannes Huebschmann

Given a suitable functor T:C -> D between model categories, we define a long exact sequence relating the homotopy groups of any X in C with those of TX, and use this to describe an obstruction theory for lifting an object G in D to C.…

Algebraic Topology · Mathematics 2007-05-23 David Blanc

We introduce a non commutative analog of the Bohr compactification. Starting from a general quantum group G we define a compact quantum group bG which has a universal property such as the universal property of the classical Bohr…

Operator Algebras · Mathematics 2007-07-17 P. M. Sołtan

We show that, in all metric theories of gravity with a general covariant action, gravity couples to the gravitational energy-momentum tensor in the same way it couples to the matter energy-momentum tensor order by order in the weak field…

General Relativity and Quantum Cosmology · Physics 2017-10-25 Tomas Ortin

Fix a prime $p$. Since their definition in the context of Localization Theory, the homotopy functors $P_{B\Z/p}$ and $CW_{B\Z/p}$ have shown to be powerful tools to understand and describe the mod $p$ structure of a space. In this paper, we…

Algebraic Topology · Mathematics 2012-10-30 Natàlia Castellana , Ramón Flores

We introduce and study equivariant Seiberg-Witten invariants for $4$-manifolds equipped with a smooth action of a finite group $G$. Our invariants come in two types: cohomological, valued in the group cohomology of $G$ and $K$-theoretic,…

Differential Geometry · Mathematics 2024-06-04 David Baraglia

We introduce the notion of (homological) G-smoothness for a complex G-variety X, where G is a connected affine algebraic group. This is based on the notion of smoothness for dg algebras and uses a suitable enhancement of the G-equivariant…

K-Theory and Homology · Mathematics 2018-05-16 Valery A. Lunts , Olaf M. Schnürer

The problem of equivariant rigidity is the $\Gamma$-homeomorphism classification of $\Gamma$-actions on manifolds with compact quotient and with contractible fixed sets for all finite subgroups of $\Gamma$. In other words, this is the…

Geometric Topology · Mathematics 2015-12-15 Frank Connolly , James F. Davis , Qayum Khan

Let $G$ be an infinite discrete group and let $\underline{E}G$ be a classifying space for proper actions of $G$. Every $G$-equivariant vector bundle over $\underline{E}G$ gives rise to a compatible collection of representations of the…

Algebraic Topology · Mathematics 2017-02-08 Dieter Degrijse , Ian J. Leary

Every principal G-bundle is classified up to equivalence by a homotopy class of maps into the classifying space of G. On the other hand, for every nice topological space Milnor constructed a strict model of loop space, that is a group.…

Algebraic Topology · Mathematics 2016-02-24 Martina Rovelli

In equivariant geometry, a localization (a.k.a., concentration) theorem is typically interpreted as a relationship between the equivariant geometry of a space with a group action and the geometry of its fixed locus. We take a different…

Algebraic Geometry · Mathematics 2025-11-06 Daniel Halpern-Leistner