中文
相关论文

相关论文: The Cuntz semigroup and stability of close C*-alge…

200 篇论文

In this paper we show that for an almost finite minimal ample groupoid $G$, its reduced $\mathrm{C}^*$-algebra $C_r^*(G)$ has real rank zero and strict comparison even though $C_r^*(G)$ may not be nuclear in general. Moreover, if we further…

算子代数 · 数学 2020-03-05 Pere Ara , Christian Bönicke , Joan Bosa , Kang Li

In this paper, we exhibit two unital, separable, nuclear ${\rm C}^*$-algebras of stable rank one and real rank zero with the same ordered scaled total K-theory, but they are not isomorphic with each other, which forms a counterexample to…

算子代数 · 数学 2024-08-29 Qingnan An , Zhichao Liu

We construct uncountably many mutually nonisomorphic simple separable stably finite unital exact C$^\ast$-algebras which are not isomorphic to their opposite algebras. In particular, we prove that there are uncountably many possibilities…

算子代数 · 数学 2024-02-14 N. Christopher Phillips , Maria Grazia Viola

A group may be considered $C^*$-stable if almost representations of the group in a $C^*$-algebra are always close to actual representations. We initiate a systematic study of which discrete groups are $C^*$-stable or only stable with…

算子代数 · 数学 2021-04-21 Søren Eilers , Tatiana Shulman , Adam P. W. Sørensen

We prove that faithful traces on separable and nuclear C*-algebras in the UCT class are quasidiagonal. This has a number of consequences. Firstly, by results of many hands, the classification of unital, separable, simple and nuclear…

算子代数 · 数学 2016-12-07 Aaron Tikuisis , Stuart White , Wilhelm Winter

It is shown that, for a C*-algebra of stable rank one (i.e., in which the invertible elements are dense), two well-known isomorphism invariants, the Cuntz semigroup and the Thomsen semigroup, contain the same information. More precisely,…

算子代数 · 数学 2011-11-10 Alin Ciuperca , George A. Elliott

A C*-algebra is said to be K-stable if its nonstable K-groups are naturally isomorphic to the usual K-theory groups. We study continuous $C(X)$-algebras, each of whose fibers are K-stable. We show that such an algebra is itself K-stable…

算子代数 · 数学 2020-05-11 Apurva Seth , Prahlad Vaidyanathan

We address the classification problem for graph $C^*$-algebras of finite graphs (finitely many edges and vertices), containing the class of Cuntz-Krieger algebras as a prominent special case. Contrasting earlier work, we do not assume that…

算子代数 · 数学 2018-03-05 Søren Eilers , Gunnar Restorff , Efren Ruiz , Adam P. W. Sørensen

We define continuous C*-algebras over a topological space X and establish some basic results. If X is a locally compact Hausdorff space, continuous C*-algebras over X are equivalent to ordinary continuous C_0(X)-algebras. The main purpose…

算子代数 · 数学 2011-07-28 Mitsuharu Takeori

The classical Cuntz semigroup has an important role in the study of C*-algebras, being one of the main invariants used to classify recalcitrant C*-algebras up to isomorphism. We consider C*-algebras that have Hopf algebra structure, and…

算子代数 · 数学 2018-02-21 Dan Kucerovsky

We prove that the reduced group C*-algebras of infinite countable discrete groups having topologically-free extreme boundaries, or more generally groups that satisfy certain combinatorial property including all acylindrically hyperbolic…

算子代数 · 数学 2026-04-27 Narutaka Ozawa

We prove that a graph C*-algebra with exactly one proper nontrivial ideal is classified up to stable isomorphism by its associated six-term exact sequence in K-theory. We prove that a similar classification also holds for a graph C*-algebra…

算子代数 · 数学 2009-06-26 Soren Eilers , Mark Tomforde

We consider three notions of divisibility in the Cuntz semigroup of a C*-algebra, and show how they reflect properties of the C*-algebra. We develop methods to construct (simple and non-simple) C*-algebras with specific divisibility…

算子代数 · 数学 2014-02-26 Leonel Robert , Mikael Rordam

We introduce the notion of a computably strongly self-absorbing C*-algebra and show that the following C*-algebras are computably strongly self-absorbing: the Cuntz algebras $\mathcal{O}_2$ and $\mathcal{O}_\infty$, the UHF algebra…

逻辑 · 数学 2024-09-30 Isaac Goldbring

We develop a theory of type semigroups for arbitrary twisted, not necessarily Hausdorff \'etale groupoids. The type semigroup is a dynamical version of the Cuntz semigroup. We relate it to traces, ideals, pure infiniteness, and stable…

算子代数 · 数学 2025-03-28 Bartosz K. Kwaśniewski , Ralf Meyer , Akshara Prasad

It is shown in this paper that two positive elements of a C*-algebra agree on all lower semicontinuous traces if and only if they are equivalent in the sense of Cuntz and Pedersen. A similar result is also obtained in the more general case…

算子代数 · 数学 2008-06-11 Leonel Robert

In this paper we study structural properties of the Cuntz semigroup and its functionals for continuous fields of C*-algebras over finite dimensional spaces. In a variety of cases, this leads to an answer to a conjecture posed by Blackadar…

算子代数 · 数学 2013-06-07 Ramon Antoine , Joan Bosa , Francesc Perera , Henning Petzka

Let A be a simple, unital, exact, and finite C*-algebra which absorbs the Jiang-Su algebra Z tensorially. We prove that the Cuntz semigroup of A admits a complete order embedding into an ordered semigroup obtained from the Elliott invariant…

算子代数 · 数学 2007-05-23 Francesc Perera , Andrew S. Toms

The Jiang--Su algebra Z has come to prominence in the classification program for nuclear C*-algebras of late, due primarily to the fact that Elliott's classification conjecture predicts that all simple, separable, and nuclear C*-algebras…

算子代数 · 数学 2007-05-23 Andrew S. Toms , Wilhelm Winter

We show that the class of C*-algebras with stable rank greater than a given positive integer is axiomatizable in logic of metric structures. As a consequence we show that the stable rank is continuous with respect to forming ultrapowers of…

算子代数 · 数学 2017-01-18 Ilijas Farah , Mikael Rørdam