English
Related papers

Related papers: K-theory for the maximal Roe algebra of certain ex…

200 papers

We provide a characterization of when a coarse equivalence between coarse disjoint unions of expander graphs is close to a bijective coarse equivalence. We use this to show that if the uniform Roe algebras of coarse disjoint unions of…

Metric Geometry · Mathematics 2023-07-24 Florent Baudier , Bruno de Mendonça Braga , Ilijas Farah , Alessandro Vignati , Rufus Willett

It is proved that the assembly maps in algebraic K- and L-theory with respect to the family of finite subgroups is injective for groups with finite asymptotic dimension that admit a finite model for the classifying space for proper actions.…

K-Theory and Homology · Mathematics 2016-09-23 Arthur Bartels , David Rosenthal

A covering of k-graphs (in the sense of Pask-Quigg-Raeburn) induces an embedding of universal C*-algebras. We show how to build a (k+1)-graph whose universal algebra encodes this embedding. More generally we show how to realise a direct…

Operator Algebras · Mathematics 2008-05-29 Alex Kumjian , David Pask , Aidan Sims

Every hyperbolic group acts continuously on its Gromov boundary. One can form the corresponding cross-product C*-algebra A. We show that there always exists a canonical Poincare duality map from the K-theory of A to the K-homology of A. We…

K-Theory and Homology · Mathematics 2010-09-28 Heath Emerson

In this paper we introduce the notion of pure non-characteristically nilpotent Lie algebra and under a condition we prove that a complex maximal extension of a finite-dimensional pure non-characteristically nilpotent Lie algebra is…

Rings and Algebras · Mathematics 2022-07-21 K. K. Abdurasulov , B. A. Omirov

Let $A$ be a C*-algebra that is the norm closure $A = \overline{\sum_{\beta \in \alpha} I_\beta}$ of an arbitrary sum of C*-ideals $I_\beta \subseteq A$. We construct a homological spectral sequence that takes as input the K-theory of…

K-Theory and Homology · Mathematics 2019-05-13 Simon Naarmann

We show that the quasi-local algebra of a coarse disjoint union of expander graphs does not contain a Cartan subalgebra isomorphic to $\ell_\infty$. N. Ozawa has recently shown that these algebras are distinct from the uniform Roe algebras…

Operator Algebras · Mathematics 2025-11-25 Bruno M. Braga , Ján Špakula , Alessandro Vignati

For a compact complex manifold, we introduce holomorphic foliations associated with certain abelian subgroups of the automorphism group. Such foliations are generalizations of holomorphic principal torus bundles. If there exists a…

Complex Variables · Mathematics 2018-01-22 Hiroaki Ishida , Hisashi Kasuya

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

In this paper we introduce the notion of an assembler, which formally encodes "cutting and pasting" data. An assembler has an associated $K$-theory spectrum, in which $\pi_0$ is the free abelian group of objects of the assembler modulo the…

K-Theory and Homology · Mathematics 2016-09-21 Inna Zakharevich

We use homological ideals in triangulated categories to get a sufficient criterion for a pair of subcategories in a triangulated category to be complementary. We apply this criterion to construct the Baum-Connes assembly map for locally…

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

This paper lays out the foundations of graded $K$-theory for Leavitt algebras associated with higher-rank graphs, also known as Kumjian-Pask algebras, establishing it as a potential tool for their classification. For a row-finite $k$-graph…

K-Theory and Homology · Mathematics 2026-05-27 Roozbeh Hazrat , Promit Mukherjee , David Pask , Sujit Kumar Sardar

Consider the wreath product $\Gamma = F\wr \mathrm{F_n} = \bigoplus_{\mathrm{F_n}}F\rtimes\mathrm{F_n}$, with $F$ a finite group and $\mathrm{F_n}$ the free group on $n$ generators. We study the Baum-Connes conjecture for this group. Our…

Operator Algebras · Mathematics 2019-11-13 Sanaz Pooya

We study some reduced free products of C*-algebras with amalgamations. We give sufficient conditions for the positive cone of the K_0 group to be the largest possible. We also give sufficient conditions for simplicity and uniqueness of…

Operator Algebras · Mathematics 2007-09-04 Nikolay A. Ivanov

We establish isomorphism ranges for the comparison maps between algebraic and topological K-groups, extending classical Quillen-Lichtenbaum conjecture to separated complex schemes of finite type after refinement. Additionally, we…

Algebraic Geometry · Mathematics 2026-05-01 Chunhui Wei

We obtain the equivariant K-homology of the classifying space \underline{E}W for W a right-angled or, more generally, an even Coxeter group. The key result is a formula for the relative Bredon homology of \underline{E}W in terms of Coxeter…

K-Theory and Homology · Mathematics 2009-08-07 Ruben Sanchez-Garcia

For an ample groupoid with torsion-free stabilizers, we construct a Chern character map going from the domain of the Baum-Connes assembly map of G to the groupoid homology groups of G with rational coefficients. As a main application,…

K-Theory and Homology · Mathematics 2025-09-10 Valerio Proietti , Makoto Yamashita

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

We study a modified version of Rognes' logarithmic structures on structured ring spectra. In our setup, we obtain canonical logarithmic structures on connective K-theory spectra which approximate the respective periodic spectra. The…

Algebraic Topology · Mathematics 2014-11-11 Steffen Sagave

The Baum-Connes conjecture predicts that a certain assembly map is an isomorphism. We identify the homotopy theoretical construction of the assembly map by Davis and L\"uck with the category theoretical construction by Meyer and Nest. This…

K-Theory and Homology · Mathematics 2022-02-01 Julian Kranz