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Related papers: Controlled $K$-theory and $K$-Homology

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Let $X$ be a discrete metric space with bounded geometry. We show that if $X$ admits an "A-by-CE coarse fibration", then the canonical quotient map $\lambda: C^*_{\max}(X)\to C^*(X)$ from the maximal Roe algebra to the Roe algebra of $X$,…

Operator Algebras · Mathematics 2021-11-12 Liang Guo , Zheng Luo , Qin Wang , Yazhou Zhang

We develop a version of controlled algebra for simplicial rings. This generalizes the methods which lead to successful proofs of the algebraic K- theory isomorphism conjecture (Farrell-Jones Conjecture) for a large class of groups. This is…

K-Theory and Homology · Mathematics 2014-06-24 Mark Ullmann

Let $A$ be a C*-algebra, $J \subset A$ a C*-subalgebra, and let $B$ be a stable C*-algebra. Under modest assumptions we organize invertible C*-extensions of $A$ by $B$ that are trivial when restricted onto $J$ to become a group…

Operator Algebras · Mathematics 2007-05-23 V. Manuilov , K. Thomsen

In this paper we give a formula for the $K$-theory of the $C^*$-algebra of a weakly left-resolving labelled space. This is done by realising the $C^*$-algebra of a weakly left-resolving labelled space as the Cuntz-Pimsner algebra of a…

Operator Algebras · Mathematics 2017-05-10 Teresa Bates , Toke Meier Carlsen , David Pask

Let $F$ be a finite group. We consider the lamplighter group $L=F\wr\mathbb{Z}$ over $F$. We prove that $L$ has a classifying space for proper actions $\underline{E} L$ which is a complex of dimension two. We use this to give an explicit…

Operator Algebras · Mathematics 2017-09-06 Ramón Flores , Sanaz Pooya , Alain Valette

In this paper we establish a direct connection between stable approximate unitary equivalence for $*$-homomorphisms and the topology of the KK-groups which avoids entirely C*-algebra extension theory and does not require nuclearity…

Operator Algebras · Mathematics 2016-09-07 Marius Dadarlat

Given a connected and locally compact Hausdorff space X with a good base K we assign, in a functorial way, a C(X)-algebra to any precosheaf of C*-algebras A defined over K. Afterwards we consider the representation theory and the Kasparov…

Operator Algebras · Mathematics 2014-05-16 Giuseppe Ruzzi , Ezio Vasselli

Algebraic $K$-theory is a homology theory that behaves very well on sufficiently nice objects such as stable $C^*$-algebras or smooth algebraic varieties, and very badly in singular situations. This survey explains how to exploit this to…

K-Theory and Homology · Mathematics 2014-03-06 Guillermo Cortiñas

The mid-seventies' works on C*-algebras of Brown-Douglas-Fillmore and Elliott both contained uniqueness and existence results in a now standard sense. These papers served as keystones for two separate theories -- KK-theory and the…

Operator Algebras · Mathematics 2007-05-23 Marius Dadarlat , Soren Eilers

We construct uncountably many mutually nonisomorphic simple separable stably finite unital exact C$^\ast$-algebras which are not isomorphic to their opposite algebras. In particular, we prove that there are uncountably many possibilities…

Operator Algebras · Mathematics 2024-02-14 N. Christopher Phillips , Maria Grazia Viola

We study the C*-algebra crossed product $C_0(X)\rtimes G$ of a locally compact group $G$ acting properly on a locally compact Hausdorff space $X$. Under some mild extra conditions, which are automatic if $G$ is discrete or a Lie group, we…

K-Theory and Homology · Mathematics 2010-12-24 Heath Emerson , Siegfried Echterhoff

Let $\sigma$ be the involution of the Roe algebra $\Roe{\RR}$ which is induced from the reflection $\RR\to\RR; x\mapsto -x$. A graded Fredholm module over a separable $C^*$-algebra $A$ gives rise to a homomorphism…

K-Theory and Homology · Mathematics 2010-03-10 Robert Yuncken

We expose a K-theoretic approach to study group C*-algebras and C*-algebraic compact quantum groups: 1. The conception of multidimensional geometric quantization and the index of group C*-algebras; 2. the entire homology of noncommutative…

K-Theory and Homology · Mathematics 2007-05-23 Do Ngoc Diep

We study the index homomorphism of even K-groups arising from a class in even KK-theory via the Kasparov product. Due to the seminal work of Baaj and Julg, under mild conditions on the C^*-algebras in question such a class in KK-theory can…

K-Theory and Homology · Mathematics 2025-08-13 Jens Kaad

Given a manifold with corners $X$, we associates to it the corner structure simplicial complex $\Sigma_X$. Its reduced K-homology is isomorphic to the K-theory of the $C^*$-algebra $\mathcal{K}_b(X)$ of b-compact operators on $X$. Moreover,…

K-Theory and Homology · Mathematics 2022-10-06 Thomas Schick , Mario Velasquez

We develop an algebraic formalism for topological $\mathbb{T}$-duality. More precisely, we show that topological $\mathbb{T}$-duality actually induces an isomorphism between noncommutative motives that in turn implements the well-known…

K-Theory and Homology · Mathematics 2015-05-15 Snigdhayan Mahanta

We study the twisted K-theory and K-homology of some infinite dimensional spaces, like SU(\infty), in the bivariant setting. Using a general procedure due to Cuntz we construct a bivariant K-theory on the category of separable…

K-Theory and Homology · Mathematics 2015-11-03 Snigdhayan Mahanta

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

Locally trivial bundles of $C^*$-algebras with fibre $D \otimes \mathcal{K}$ for a strongly self-absorbing $C^*$-algebra $D$ over a finite CW-complex $X$ form a group $E^1_D(X)$ that is the first group of a cohomology theory $E^*_D(X)$. In…

Operator Algebras · Mathematics 2026-01-08 Marius Dadarlat , James E. McClure , Ulrich Pennig

We give a description of the value of a finitary localizing invariant, such as algebraic $K$-theory, on the category of sheaves on a locally coherent space $X$. This in particular includes all spaces that arise as spectra of commutative…

K-Theory and Homology · Mathematics 2025-10-16 Georg Lehner