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Related papers: A note on the real coarse Baum-Connes conjecture

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Using the language of coarse homology theories, we provide an axiomatic account of vanishing results for the fibres of forget-control maps associated to spaces with equivariant finite decomposition complexity.

K-Theory and Homology · Mathematics 2019-10-30 Ulrich Bunke , Alexander Engel , Daniel Kasprowski , Christoph Winges

Using the Evans spectral sequence and its counter-part for real $K$-theory, we compute both the real and complex $K$-theory of several infinite families of $C^*$-algebras based on higher-rank graphs of rank $3$ and $4$. The higher-rank…

Operator Algebras · Mathematics 2025-02-26 Jeffrey L Boersema , Alina Vdovina

We consider the equivariant Kasparov category associated to an \'etale groupoid, and by leveraging its triangulated structure we study its localization at the "weakly contractible" objects, extending previous work by R. Meyer and R. Nest.…

K-Theory and Homology · Mathematics 2024-12-23 Christian Bönicke , Valerio Proietti

We define and study an analogue of the Baum-Connes assembly map for complex semisimple quantum groups, that is, Drinfeld doubles of $ q $-deformations of compact semisimple Lie groups. Our starting point is the deformation picture of the…

Operator Algebras · Mathematics 2018-04-26 Andrew Monk , Christian Voigt

We construct the geometric Baum-Connes assembly map for twisted Lie groupoids, that means for Lie groupoids together with a given groupoid equivariant $PU(H)-$principle bundle. The construction is based on the use of geometric deformation…

K-Theory and Homology · Mathematics 2016-02-29 Paulo Carrillo Rouse , Bai-Ling Wang

We prove the Baum--Connes conjecture with arbitrary coefficients for some classes of groups: (1) Linear algebraic groups over a non-archimedean local field. (2) Linear algebraic groups over the adeles of a global field k, provided that at…

K-Theory and Homology · Mathematics 2019-04-08 Maarten Solleveld

The $K$-theory of the stable Higson corona of a coarse space carries a canonical ring structure. This ring is the domain of an unreduced version of the coarse co-assembly map of Emerson and Meyer. We show that the target also carries a ring…

K-Theory and Homology · Mathematics 2014-12-05 Christopher Wulff

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

We present an alternative approach to the result of Guentner, Higson, and Weinberger concerning the Baum-Connes conjecture for finitely generated subgroups of SL(2,C). Using finite-dimensional methods, we show that the Baum-Connes assembly…

Group Theory · Mathematics 2007-12-24 Dmitry Matsnev

We formulate a version of Baum-Connes' conjecture for a discrete quantum group, building on our earlier work (\cite{GK}). Given such a quantum group $\cla$, we construct a directed family $\{\cle_F \}$ of $C^*$-algebras ($F$ varying over…

K-Theory and Homology · Mathematics 2007-05-23 Debashish Goswami , A. O. Kuku

There are a number of (co-)homology theories on coarse spaces. Controlled operator K-theory is by far the most popular one of them. Our approach is geometric. We study when does the Roe-algebra of a space restrict to a subspace. Then we…

K-Theory and Homology · Mathematics 2022-03-17 Elisa Hartmann

We study Hecke pairs using the coarse geometry of their coset space and their Schlichting completion. We prove new stability results for the Baum-Connes and the Novikov conjectures in the case where the pair is co-Haagerup. This allows to…

K-Theory and Homology · Mathematics 2023-05-03 Clément Dell'Aiera

We study equivariant coarse homology theories through an axiomatic framework. To this end we introduce the category of equivariant bornological coarse spaces and construct the universal equivariant coarse homology theory with values in the…

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

We introduce a notion of fibred coarse embedding into Hilbert space for metric spaces, which is a generalization of Gromov's notion of coarse embedding into Hilbert space. It turns out that a large class of expander graphs admit such an…

K-Theory and Homology · Mathematics 2012-08-23 Xiaoman Chen , Qin Wang , Guoliang Yu

The equivariant coarse Baum-Connes conjecture interpolates between the Baum-Connes conjecture for a discrete group and the coarse Baum-Connes conjecture for a proper metric space. In this paper, we study this conjecture under certain…

K-Theory and Homology · Mathematics 2021-10-20 Jintao Deng , Benyin Fu , Qin Wang

We study the coarse motive of the quotient $\mathcal{O}^{\infty}(X)//G$ of the cone of a uniform bornological coarse space $X$ with $G$-action. If $X$ admits a sufficiently ergodic probability measure, then we show that the coarse assembly…

Algebraic Topology · Mathematics 2026-05-28 Ulrich Bunke

Recently R\"ussmann proposed a new new variant of KAM theory based on a slowly converging iteration scheme. It is the purpose of this note to make this scheme accessible in an even simpler setting, namely for analytic perturbations of…

Dynamical Systems · Mathematics 2015-05-14 Jürgen Pöschel

We study the $K$-theory and Swan theory of the group ring $R[G]$, when $G$ is a finite group and $R$ is any ring or ring spectrum. In this setting, the well-known assembly map for $K(R[G])$ has a companion called the coassembly map. We…

Algebraic Topology · Mathematics 2016-11-24 Cary Malkiewich

A coarse description of a subset A of omega is a subset D of omega such that the symmetric difference of A and D has asymptotic density 0. We study the extent to which noncomputable information can be effectively recovered from all coarse…

Logic · Mathematics 2015-05-08 Denis R. Hirschfeldt , Carl G. Jockusch , Rutger Kuyper , Paul E. Schupp

In this paper, we generalize the Dirac-dual-Dirac method to Hecke pairs with equivariant coarse embeddings and establish the K-theoretic isomorphisms between the maximal and reduced equivariant Roe algebras. We also extend these results to…

K-Theory and Homology · Mathematics 2026-02-03 Liang Guo , Hang Wang , Xiufeng Yao