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Related papers: Topological equivariant coarse K-homology

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Let G be a finite group. We systematically exploit general homological methods in order to reduce the computation of G-equivariant KK-theory to topological equivariant K-theory. The key observation is that the functor assigning to a…

Operator Algebras · Mathematics 2016-05-11 Ivo Dell'Ambrogio

For a countable discrete group $G$, we construct a new and concrete model for the equivariant topological $K$-homology theory of $G$, which is defined for all $G$-actions, not just for proper $G$-actions. The construction of our model…

K-Theory and Homology · Mathematics 2022-09-07 Kun Wang

Index maps taking values in the $K$-theory of a mapping cone are defined and discussed. The resulting index theorem can be viewed in analogy with the Freed-Melrose index theorem. The framework of geometric $K$-homology is used in a…

K-Theory and Homology · Mathematics 2016-03-11 Robin J. Deeley

The equivariant coarse index is well-understood and widely used for actions by discrete groups. We extend the definition of this index to general locally compact groups. We use a suitable notion of admissible modules over $C^*$-algebras of…

K-Theory and Homology · Mathematics 2022-07-05 Hao Guo , Peter Hochs , Varghese Mathai

It is characterized when coarsening functors between categories of graded modules preserve injectivity of objects, and when they commute with graded covariant Hom functors.

Commutative Algebra · Mathematics 2013-04-09 Fred Rohrer

We present a version of higher Hochschild homology for spaces equipped with principal bundles for a structure group $G$. As coefficients, we allow $E_\infty$-algebras with $G$-action. For this homology theory, we establish an equivariant…

Algebraic Topology · Mathematics 2019-05-13 Lukas Müller , Lukas Woike

This survey article on relative homological algebra in bivariant K-thoery is mainly intended for readers with a background knowledge in triangulated categories. We briefly recall the general theory of relative homological algebra in…

Operator Algebras · Mathematics 2023-03-03 George Nadareishvili

We demonstrate that any full and faithful $*$-functor between approximable categories of locally finite coarse spaces induces a coarse embedding between the underlying spaces. Furthermore, we establish a general characterisation of such…

Operator Algebras · Mathematics 2025-03-11 Kostyantyn Krutoy

We construct an equivariant coarse homology theory arising from the algebraic $K$-theory of spherical group rings and use this theory to derive split injectivity results for associated assembly maps. On the way, we prove that the…

K-Theory and Homology · Mathematics 2021-05-28 Ulrich Bunke , Daniel Kasprowski , Christoph Winges

Using methods from coarse topology we show that fundamental classes of closed enlargeable manifolds map non-trivially both to the rational homology of their fundamental groups and to the K-theory of the corresponding reduced C*-algebras.…

Algebraic Topology · Mathematics 2018-11-28 B. Hanke , D. Kotschick , J. Roe , T. Schick

This monograph introduces a framework for genuine proper equivariant stable homotopy theory for Lie groups. The adjective `proper' alludes to the feature that equivalences are tested on compact subgroups, and that the objects are built from…

Algebraic Topology · Mathematics 2023-08-15 Dieter Degrijse , Markus Hausmann , Wolfgang Lück , Irakli Patchkoria , Stefan Schwede

We introduce and compare two approaches to equivariant homotopy theory in a topological or ordinary Quillen model category. For the topological model category of spaces, we generalize Piacenza's result that the categories of topological…

Algebraic Topology · Mathematics 2017-03-06 Marc Stephan

In 1998, Goresky, Kottwitz, and MacPherson showed that for certain projective varieties X equipped with an algebraic action of a complex torus T, the equivariant cohomology ring H_T(X) can be described by combinatorial data obtained from…

Algebraic Topology · Mathematics 2007-05-23 Megumi Harada , Andre Henriques , Tara S. Holm

We begin the study the algebraic topology of semi-coarse spaces, which are generalizations of coarse spaces that enable one to endow non-trivial `coarse-like' structures to compact metric spaces, something which is impossible in coarse…

Algebraic Topology · Mathematics 2024-10-01 Antonio Rieser , Jonathan Treviño-Marroquín

We define the orbit category for transitive topological groupoids and their equivariant CW-complexes. By using these constructions we define equivariant Bredon homology and cohomology for actions of transitive topological groupoids. We show…

Algebraic Topology · Mathematics 2019-11-11 Carla Farsi , Laura Scull , Jordan Watts

This is the second installment in a series of papers applying descriptive set theoretic techniques to both analyze and enrich classical functors from homological algebra and algebraic topology. In it, we show that the \v{C}ech cohomology…

Logic · Mathematics 2024-11-20 Jeffrey Bergfalk , Martino Lupini , Aristotelis Panagiotopoulos

Let A be a dg category, F:A->A a dg functor inducing an equivalence of categories in degree-zero cohomology, and A/F the associated dg orbit category. For every A1-homotopy invariant (e.g. homotopy K-theory, K-theory with coefficients,…

K-Theory and Homology · Mathematics 2015-03-10 Goncalo Tabuada

We compute the equivariant complex K-theory ring of a cohomogeneity-one action of a compact Lie group at the level of generators and relations and derive a characterization of K-theoretic equivariant formality for these actions. Less…

Algebraic Topology · Mathematics 2022-03-15 Jeffrey D. Carlson

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

A kind of unstable homotopy theory on the category of associative rings (without unit) is developed. There are the notions of fibrations, homotopy (in the sense of Karoubi), path spaces, Puppe sequences, etc. One introduces the notion of a…

K-Theory and Homology · Mathematics 2007-05-23 Grigory Garkusha