English
Related papers

Related papers: Limit C*-algebras associated with an automorphism

200 papers

It is now well known that a simple graph $C^*$-algebra $C^*(E)$ of a directed graph $E$ is either AF or purely infinite. In this paper, we address the question of whether this is the case for labeled graph $C^*$-algebras recently introduced…

Operator Algebras · Mathematics 2016-03-01 Ja A Jeong , Eun Ji Kang , Sun Ho Kim , Gi Hyun Park

In the present paper we study the structure of C^*-algebras generated by the components of the polar decompositions of operators in Hilbert space satisfying certain commutation relations.

Operator Algebras · Mathematics 2007-05-23 A. Lebedev , A. Odzijewicz

Let $\Delta$ be a building of type $\widetilde A_2$ and order $q$, with maximal boundary $\Omega$. Let $\Gamma$ be a group of type preserving automorphisms of $\Delta$ which acts regularly on the chambers of $\Delta$. Then the crossed…

Operator Algebras · Mathematics 2014-07-29 Guyan Robertson

k-graphs are higher-rank analogues of directed graphs which were first developed to provide combinatorial models for operator algebras of Cuntz-Krieger type. Here we develop the theory of covering spaces for k-graphs, obtaining a…

Operator Algebras · Mathematics 2008-05-23 David Pask , John Quigg , Iain Raeburn

Let $G=K\ltimes A$ be the semi-direct product group of a compact group $K$ acting on an abelian locally compact group $A$. We describe the $C^*$-algebra $C^*(G)$ of $G$ in terms of an algebra of operator fields defined over the spectrum of…

Operator Algebras · Mathematics 2019-04-23 Hedi Regeiba , Jean Ludwig

In this paper, we develop a quantitative K-theory for filtered C*-algebras. Particularly interesting examples of filtered C*-algebras include group C*-algebras, crossed product C*-algebras and Roe algebras. We prove a quantitative version…

Operator Algebras · Mathematics 2012-04-17 Hervé Oyono-Oyono , Guoliang Yu

Given a quasi-special endomorphism $\rho$ of a C*-algebra A with nontrivial center, we study an extension problem for automorphisms of A to a minimal cross-product B of A by $\rho$. Exploiting some aspects of the underlying generalized…

Operator Algebras · Mathematics 2011-11-21 Roberto Conti , Ezio Vasselli

We prove that the pure state space is homogeneous under the action of the automorphism group (or a certain smaller group of approximately inner automorphisms) for a fairly large class of simple separable nuclear C*-algebras, including the…

Operator Algebras · Mathematics 2007-05-23 H. Futamura , N. Kataoka , A. Kishimoto

A construction of reversible extensions of dynamical systems which applies to arbitrary mappings (not necessarily with open range) is presented. It is based on calculating the maximal ideal space of C*-algebras that extends endomorphisms to…

Dynamical Systems · Mathematics 2013-08-27 B. K. Kwasniewski

A classification result is obtained for the C*-algebras that are (stably isomorphic to) inductive limits of 1-dimensional noncommutative CW complexes with trivial $K_1$-group. The classifying functor Cu is defined in terms of the Cuntz…

Operator Algebras · Mathematics 2012-08-28 Leonel Robert

We give a simplified proof of the Berger-Coburn theorem on the boundedness of Toeplitz operators and extend this theorem to the setting of $p$-Fock spaces $(1\leq p \leq \infty)$. We present an overview of recent results by various authors…

Operator Algebras · Mathematics 2019-06-24 Wolfram Bauer , Robert Fulsche

For a directed graph $E$, we compute the $K$-theory of the $C^*$-algebra $C^*(E)$ from the Cuntz-Krieger generators and relations. First we compute the $K$-theory of the crossed product $C^*(E)\times_\gamma\IT$, and then using duality and…

Operator Algebras · Mathematics 2009-06-23 Menassie Ephrem , Jack Spielberg

We show that if $A$ is $\mathcal{Z}$, $\mathcal{O}_2$, $\mathcal{O}_{\infty}$, a UHF algebra of infinite type, or the tensor product of a UHF algebra of infinite type and $\mathcal{O}_{\infty}$, then the conjugation action $\mathrm{Aut}(A)…

Operator Algebras · Mathematics 2017-08-09 David Kerr , Martino Lupini , N. Christopher Phillips

Let ${\sf CK}_{*}$ denote the C$^{*}$-algebra defined by the direct sum of all Cuntz-Krieger algebras. We introduce a comultiplication $\Delta_{\phi}$ and a counit $\epsilon$ on ${\sf CK}_{*}$ such that $\Delta_{\phi}$ is a nondegenerate…

Operator Algebras · Mathematics 2008-04-10 Katsunori Kawamura

To a domain with conical points \Omega, we associate a natural C*-algebra that is motivated by the study of boundary value problems on \Omega, especially using the method of layer potentials. In two dimensions, we allow \Omega to be a…

Operator Algebras · Mathematics 2011-11-28 Catarina Carvalho , Yu Qiao

We study and classify free actions of compact quantum groups on unital C*-algebras in terms of generalized factor systems. Moreover, we use these factor systems to show that all finite coverings of irrational rotation C*-algebras are cleft.

Operator Algebras · Mathematics 2017-08-10 Kay Schwieger , Stefan Wagner

We associate with the ring $R$ of algebraic integers in a number field a C*-algebra $\cT[R]$. It is an extension of the ring C*-algebra $\cA[R]$ studied previously by the first named author in collaboration with X.Li. In contrast to…

Operator Algebras · Mathematics 2012-06-12 Joachim Cuntz , Christopher Deninger , Marcelo Laca

Starting from an arbitrary endomorphism $\alpha$ of a unital C*-algebra $A$ we construct a bigger C*-algebra $B$ and extend $\alpha$ onto $B$ in such a way that the extended endomorphism $\alpha$ has a unital kernel and a hereditary range,…

Operator Algebras · Mathematics 2016-12-01 B. K. Kwaśniewski

We give a construction of a nuclear $C^\ast$-algebra associated with an amalgamated free product of groups, generalizing Spielberg's construction of a certain Cuntz-Krieger algebra associated with a finitely generated free product of cyclic…

Operator Algebras · Mathematics 2007-05-23 Rui Okayasu

We associate a $C^*$-algebra to a partial action of the integers acting on the base space of a vector bundle, using the framework of Cuntz--Pimsner algebras. We investigate the structure of the fixed point algebra under the canonical gauge…

Operator Algebras · Mathematics 2025-06-23 Aaron Kettner
‹ Prev 1 8 9 10 Next ›