English
Related papers

Related papers: Non-Hausdorff groupoids, proper actions and K-theo…

200 papers

We introduce a notion of Morita equivalence for non-selfadjoint operator algebras equipped with a completely isometric involution (operator *-algebras). We then show that the unbounded Kasparov product by a Morita equivalence bimodule…

K-Theory and Homology · Mathematics 2016-12-28 Jens Kaad

A groupoid correspondence on an etale, locally compact groupoid induces a C*-correspondence on its groupoid C*-algebra. We show that the Cuntz-Pimsner algebra for this C*-correspondence relative to an ideal associated to an open invariant…

Operator Algebras · Mathematics 2026-05-20 Ralf Meyer

Given C*-algebras A and B and an imprimitivity A-B-bimodule X, we construct an explicit isomorphism X_* : K_i(A) --> K_i(B) where K_i denote the complex K-theory functors for i=0, 1. Our techniques do not require separability nor existence…

funct-an · Mathematics 2008-02-03 Ruy Exel

In the late 1980's Marc Rieffel introduced a notion of properness for actions of locally compact groups on C*-algebras which, among other things, allows the construction of generalised fixed-point algebras for such actions. In this paper we…

Operator Algebras · Mathematics 2014-09-16 Alcides Buss , Siegfried Echterhoff

In a recent article of Kenny De Commer, was investigated a Morita equivalence between locally compact quantum groups, in which a measured quantum groupoid, of basis $\mathbb{C}^2$, was constructed as a linking object. Here, we generalize…

Operator Algebras · Mathematics 2012-09-19 Michel Enock

We extend Nekrashevych's $KK$-duality for $C^*$-algebras of regular, recurrent, contracting self-similar group actions to regular, contracting self-similar groupoid actions on a graph, removing the recurrence condition entirely and…

K-Theory and Homology · Mathematics 2023-12-05 Nathan Brownlowe , Alcides Buss , Daniel Gonçalves , Jeremy B. Hume , Aidan Sims , Michael F. Whittaker

This paper constitutes a first step in the author's program to investigate the question of when a homotopy of 2-cocycles $\omega = \{\omega_t\}_{t \in [0,1]}$ on a locally compact Hausdorff groupoid $\mathcal{G}$ induces an isomorphism of…

Operator Algebras · Mathematics 2014-09-09 Elizabeth Gillaspy

A theory of Galois co-objects for von Neumann bialgebras is introduced. This concept is closely related to the notion of comonoidal W*-Morita equivalence between von Neumann bialgebras, which is a Morita equivalence taking the…

Operator Algebras · Mathematics 2013-08-13 Kenny De Commer

C*-algebras generalizing Cuntz-Krieger algebras can be associated to hyperbolic homeomorphisms of compact metric spaces. They satisfy a non-commutative form of Spanier-Whitehead duality with respect to K-theory. We prove this for the case…

funct-an · Mathematics 2009-10-28 J. Kaminker , I. Putnam

We give a dynamical characterization of categorical Morita equivalence between compact quantum groups. More precisely, by a Tannaka-Krein type duality, a unital C*-algebra endowed with commuting actions of two compact quantum groups…

Operator Algebras · Mathematics 2021-06-09 Sergey Neshveyev , Makoto Yamashita

We extend to the context of locally C*-algebras a result of F. Combes [Proc. London Math. Soc. 49(1984), 289-306].

Operator Algebras · Mathematics 2007-05-28 Maria Joita

Given a locally compact group $G$ and a unitary representation $\rho:G\to U({\mathcal H})$ on a Hilbert space ${\mathcal H}$, we construct a $C^*$-correspondence ${\mathcal E}(\rho)={\mathcal H}\otimes_{\mathbb C} C^*(G)$ over $C^*(G)$ and…

Operator Algebras · Mathematics 2016-12-30 Valentin Deaconu

We consider two categories of C*-algebras; in the first, the isomorphisms are ordinary isomorphisms, and in the second, the isomorphisms are Morita equivalences. We show how these two categories, and categories of dynamical systems based on…

Operator Algebras · Mathematics 2009-09-16 Astrid an Huef , Iain Raeburn , Dana Williams

Let G be a reductive p-adic group and let H(G)^s be a Bernstein block of the Hecke algebra of G. We consider two important topological completions of H(G)^s: a direct summand S(G)^s of the Harish-Chandra--Schwartz algebra of G and a…

Representation Theory · Mathematics 2020-09-08 Maarten Solleveld

In this letter we give an overview on recent developments in representation theory of star product algebras. In particular, we relate the *-representation theory of *-algebras over rings C = R(i) with an ordered ring R and i^2 = -1 to the…

Quantum Algebra · Mathematics 2009-11-10 Stefan Waldmann

We generalize the classification result of Restorff on Cuntz-Krieger algebras to cover all unital graph C*-algebras with real rank zero, showing that Morita equivalence in this case is determined by ordered, filtered K-theory as conjectured…

Operator Algebras · Mathematics 2015-07-09 Søren Eilers , Gunnar Restorff , Efren Ruiz , Adam P. W. Sørensen

In this note, we present criteria that are equivalent to a locally compact Hausdorff groupoid $G$ being effective. One of these conditions is that $G$ satisfies the "C*-algebraic local bisection hypothesis"; that is, that every normaliser…

Motivated by deformation quantization, we introduced in an earlier work the notion of formal Morita equivalence in the category of $^*$-algebras over a ring $\ring C$ which is the quadratic extension by $\im$ of an ordered ring $\ring R$.…

Quantum Algebra · Mathematics 2007-05-23 Henrique Bursztyn , Stefan Waldmann

In this article, we generalize to the case of regular locally compact quantum groups, two important results concerning actions of compact quantum groups. Let $G_1$ and $G_2$ be two monoidally equivalent regular locally compact quantum…

Operator Algebras · Mathematics 2018-02-27 Saad Baaj , Jonathan Crespo

This paper continues the author's program to investigate the question of when a homotopy of 2-cocycles $\Omega = \{\omega_t\}_{t \in [0,1]}$ on a locally compact Hausdorff groupoid $\mathcal{G}$ induces an isomorphism of the $K$-theory…

Operator Algebras · Mathematics 2014-10-28 Elizabeth Gillaspy