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Related papers: Banach KK-theory and the Baum-Connes conjecture

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kk$^{\text{ban}}$ is a bivariant K-theory for Banach algebras that has reasonable homological properties, a product and is Morita invariant in a very general sense. We define it here by a universal property and ensure its existence in a…

K-Theory and Homology · Mathematics 2014-06-10 Walther Paravicini

We show that the $C^*$-algebra associated by Nekrashevych to a contracting self-similar group is simple if and only if the corresponding complex $\ast$-algebra is simple. We also improve on Steinberg and Szaka\'c's algorithm to determine if…

Operator Algebras · Mathematics 2025-01-22 Eusebio Gardella , Volodymyr Nekrashevych , Benjamin Steinberg , Alina Vdovina

We strengthen a result of Hanke-Schick about the strong Novikov conjecture for low degree cohomology by showing that their non-vanishing result for the maximal group C*-algebra holds for many other exotic group C*-algebras, in particular…

K-Theory and Homology · Mathematics 2020-12-15 Paolo Antonini , Alcides Buss , Alexander Engel , Timo Siebenand

In this paper, we collect some technical results about weights on C*-algebras which are useful in de theory of locally compact quantum groups in the C*-algebra framework. We discuss the extension of a lower semi-continuous weight to a…

Operator Algebras · Mathematics 2007-05-23 Johan Kustermans , Stefaan Vaes

We make progress on a conjecture of Kahn and Kalai, the original (stronger but less general) version of what became known as the ``Kahn-Kalai Conjecture" (KKC; now a theorem of Park and Pham). This ``second" KKC concerns the threshold,…

Combinatorics · Mathematics 2025-08-21 Quentin Dubroff , Jeff Kahn , Jinyoung Park

We introduce Banach algebras associated to twisted \'etale groupoids $(\mathcal{G},\mathcal{L})$ and to twisted inverse semigroup actions. This provides a unifying framework for numerous recent papers on $L^p$-operator algebras and the…

Functional Analysis · Mathematics 2025-08-21 Krzysztof Bardadyn , Bartosz K. Kwaśniewski , Andrew McKee

Cohen, Goresky and Ji showed that there is a Kunneth theorem relating the intersection homology groups $I^{\bar p}H_*(X\times Y)$ to $I^{\bar p}H_*(X)$ and $I^{\bar p}H_*(Y)$, provided that the perversity $\bar p$ satisfies rather strict…

Geometric Topology · Mathematics 2011-03-31 Greg Friedman

We show that complex semisimple quantum groups, that is, Drinfeld doubles of $ q $-deformations of compact semisimple Lie groups, satisfy a categorical version of the Baum-Connes conjecture with trivial coefficients. This approach, based on…

K-Theory and Homology · Mathematics 2020-12-21 Christian Voigt

The paper presents a detailed description of the K-theory and K-homology of C*-algebras generated by q-normal operators including generators and the index pairing. The C*-algebras generated by q-normal operators can be viewed as a…

Quantum Algebra · Mathematics 2018-02-20 Ismael Cohen , Elmar Wagner

Let $X$ be a locally compact Hausdorff space, and $A$ be a commutative semisimple Banach algebra over the scalar field $\mathbb{C}$. The correlation between different types of BSE- Banach algebras $A$, and the Banach algebra $C_{0}(X, A)$…

Functional Analysis · Mathematics 2022-12-13 Maryam Aghakoochaki , Ali Rejali

In this paper we develop an axiomatic approach to coarse homology theories. We prove a uniqueness result concerning coarse homology theories on the category of `coarse CW-complexes'. This uniqueness result is used to prove a version of the…

Algebraic Topology · Mathematics 2014-10-01 Paul D. Mitchener

We interpret certain equivariant Kasparov groups as equivariant representable K-theory groups. We compute these groups via a classifying space and as K-theory groups of suitable sigma-C*-algebras. We also relate equivariant vector bundles…

K-Theory and Homology · Mathematics 2015-10-23 Heath Emerson , Ralf Meyer

This book treats: - spectral theory of Banach *-algebras, - basic representation theory of normed *-algebras, - spectral theory of representations of commutative *-algebras. A novel feature of the book is the construction of the enveloping…

Operator Algebras · Mathematics 2025-02-18 Marco Thill

In this paper, we verify the $\ell^p$ coarse Baum-Connes conjecture for open cones and show that the $K$-theory for $\ell^p$ Roe algebras of open cones are independent of $p\in[1,\infty)$. Combined with the result of T. Fukaya and S.-I.…

Operator Algebras · Mathematics 2022-03-22 Jianguo Zhang

We give a new proof of some cases of the Baum-Connes conjecture along the lines of a proof of the Farrell-Jones conjecture.

Algebraic Topology · Mathematics 2013-03-05 Fabian Lenhardt

Using a combination of Atiyah-Segal ideas on one side and of Connes and Baum-Connes ideas on the other, we prove that the Twisted geometric K-homology groups of a Lie groupoid have an external multiplicative structure extending hence the…

K-Theory and Homology · Mathematics 2016-03-31 Noé Bárcenas , Paulo Carrillo Rouse , Mario Velásquez

This book treats: - spectral theory of Banach *-algebras, - basic representation theory of normed *-algebras, - spectral theory of representations of commutative *-algebras. A novel feature of the book is the construction of the enveloping…

Operator Algebras · Mathematics 2008-07-29 Marco Thill

We study the possibility of applying a finite-dimensionality argument in order to address parts of the Baum-Connes conjecture for finitely generated linear groups. This gives an alternative approach to the results of Guentner, Higson, and…

Geometric Topology · Mathematics 2007-05-23 Dmitry Matsnev

These notes cover the contents of three survey lectures held at the ICTP Trieste Summer school on High dimensional manifold theory 2001. They introduce techniques coming from the theory of operator algebras. We will focus on the basic…

Geometric Topology · Mathematics 2007-05-23 Thomas Schick

Non-commutative $L^p$-spaces are shown to constitute examples of a class of Banach quasi *-algebras called CQ*-algebras. For $p\geq 2$ they are also proved to possess a {\em sufficient} family of bounded positive sesquilinear forms…

Mathematical Physics · Physics 2009-04-01 F. Bagarello , C. Trapani , S. Triolo