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Related papers: C*-algebras and their nuclear dimension

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We introduce the nuclear dimension of a C*-algebra; this is a noncommutative version of topological covering dimension based on a modification of the earlier concept of decomposition rank. Our notion behaves well with respect to inductive…

Operator Algebras · Mathematics 2009-03-31 Wilhelm Winter , Joachim Zacharias

While there is only one natural dimension concept for separable, metric spaces, the theory of dimension in noncommutative topology ramifies into different important concepts. To accommodate this, we introduce the abstract notion of a…

Operator Algebras · Mathematics 2015-01-06 Hannes Thiel

We prove that Z-stable, simple, separable, nuclear, non-unital C*-algebras have nuclear dimension at most 1. This completes the equivalence between finite nuclear dimension and Z-stability for simple, separable, nuclear, non-elementary…

Operator Algebras · Mathematics 2020-11-18 Jorge Castillejos , Samuel Evington

We compute the nuclear dimension of separable, simple, unital, nuclear, Z-stable C*-algebras. This makes classification accessible from Z-stability and in particular brings large classes of C*-algebras associated to free and minimal actions…

Operator Algebras · Mathematics 2021-04-07 Jorge Castillejos , Samuel Evington , Aaron Tikuisis , Stuart White , Wilhelm Winter

Generalizing the case of the Toeplitz algebra by Brake and Winter, we prove that the nuclear dimension of a C*-algebra extension of C(X) by the compact operators is equal to the dimension of X.

Operator Algebras · Mathematics 2023-09-28 Ruaridh Gardner , Aaron Tikuisis

We compute the nuclear dimension of extensions of C*-algebras involving commutative unital quotients and stable Kirchberg ideals. We identify the finite directed graphs whose C*-algebras are covered by this theorem.

Operator Algebras · Mathematics 2025-05-13 Samuel Evington , Abraham C. S. Ng , Aidan Sims , Stuart White

Simple, separable, unital, monotracial and nuclear C$^*$-algebras are shown to have finite nuclear dimension whenever they absorb the Jiang-Su algebra $\mathcal{Z}$ tensorially. This completes the proof of the Toms-Winter conjecture in the…

Operator Algebras · Mathematics 2015-11-30 Yasuhiko Sato , Stuart White , Wilhelm Winter

We introduce the completely positive rank, a notion of covering dimension for nuclear $C^*$-algebras and analyze some of its properties. The completely positive rank behaves nicely with respect to direct sums, quotients, ideals and…

Operator Algebras · Mathematics 2007-05-23 Wilhelm Winter

It is shown that if a C*-algebra has nuclear dimension $n$ then its Cuntz semigroup has the property of $n$-comparison. It then follows from results by Ortega, Perera, and Rordam that $\sigma$-unital C*-algebras of finite nuclear dimension…

Operator Algebras · Mathematics 2010-03-09 Leonel Robert

The main result here is that a simple separable C*-algebra is Z-stable (where Z denotes the Jiang-Su algebra) if (i) it has finite nuclear dimension or (ii) it is approximately subhomogeneous with slow dimension growth. This generalizes the…

Operator Algebras · Mathematics 2015-08-21 Aaron Tikuisis

We show that separable, nuclear and strongly purely infinite C*-algebras have finite nuclear dimension. In fact, the value is at most three. This exploits a deep structural result of Kirchberg and R{\o}rdam on strongly purely infinite…

Operator Algebras · Mathematics 2018-01-12 Gabor Szabo

The problem of expressing a selfadjoint element that is zero on every bounded trace as a finite sum (or a limit of sums) of commutators is investigated in the setting of C*-algebras of finite nuclear dimension. Upper bounds -- in terms of…

Operator Algebras · Mathematics 2013-09-03 Leonel Robert

We investigate the interplay of the following regularity properties for non-simple C*-algebras: finite nuclear dimension, Z-stability, and algebraic regularity in the Cuntz semigroup. We show that finite nuclear dimension implies algebraic…

Operator Algebras · Mathematics 2017-04-12 Leonel Robert , Aaron Tikuisis

Consider a graph C*-algebra C*(E) with a purely infinite ideal I (possibly all of C*(E)) such that I has only finitely many ideals and C*(E)/I is approximately finite dimensional. We prove that the nuclear dimension of C*(E) is 1. If I has…

Operator Algebras · Mathematics 2014-11-26 Efren Ruiz , Aidan Sims , Mark Tomforde

It is shown that a C*-algebra of the form C(X,U), where U is a UHF algebra, is not an inductive limit of subhomogeneous C*-algebras of topological dimension less than that of X. This is in sharp contrast to dimension-reduction phenomenon in…

Operator Algebras · Mathematics 2015-08-21 Aaron Tikuisis

We give a partial answer to the question for the precise value of the nuclear dimension of UCT-Kirchberg algebras raised by W. Winter and J. Zacharias. It is shown that every Kirchberg algebra in the UCT-class with torsion free $K_1$-group…

Operator Algebras · Mathematics 2017-01-03 Dominic Enders

We write arbitrary separable nuclear C*-algebras as limits of inductive systems of finite-dimensional C*-algebras with completely positive connecting maps. The characteristic feature of such CPC*-systems is that the maps become more and…

Operator Algebras · Mathematics 2024-10-10 Kristin Courtney , Wilhelm Winter

We introduce a notion of covering dimension for Cuntz semigroups of C*-algebras. This dimension is always bounded by the nuclear dimension of the C*-algebra, and for subhomogeneous C*-algebras both dimensions agree. Cuntz semigroups of…

Operator Algebras · Mathematics 2021-08-13 Hannes Thiel , Eduard Vilalta

In this article I study a number of topological and algebraic dimension type properties of simple C*-algebras and their interplay. In particular, a simple C*-algebra is defined to be (tracially) (m,\bar{m})-pure, if it has (strong tracial)…

Operator Algebras · Mathematics 2011-05-23 Wilhelm Winter

We obtain an improved upper bound for the nuclear dimension of extensions of $\mathcal{O}_\infty$-stable $\rm{C}^*$-algebras. In particular, we prove that the nuclear dimension of a full extension of an $\mathcal{O}_\infty$-stable…

Operator Algebras · Mathematics 2021-05-12 Samuel Evington
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