English
Related papers

Related papers: Stable rank of $\mathrm{C}(X)\rtimes\Gamma$

200 papers

We consider tracial stability, which requires that tuples of elements of a C*-algebra with a trace that nearly satisfy the relation are close to tuples that actually satisfy the relation. Here both "near" and "close" are in terms of the…

Operator Algebras · Mathematics 2017-06-23 Don Hadwin , Tatiana Shulman

We study a class of stably projectionless simple C*-algebras which may be viewed as having generalized tracial rank one in analogy with the unital case. Some structural question concerning these simple C*-algebras are studied. The paper…

Operator Algebras · Mathematics 2018-11-06 George A. Elliott , Guihua Gong , Huaxin Lin , Zhuang Niu

We prove simplicity of all intermediate $C^*$-algebras $C^*_{r}(\Gamma)\subseteq \mathcal{B} \subseteq \Gamma\ltimes_r C(X)$ in the case of minimal actions of $C^*$-simple groups $\Gamma$ on compact spaces $X$. For this, we use the notion…

Operator Algebras · Mathematics 2018-09-18 Tattwamasi Amrutam , Mehrdad Kalantar

We consider the notion of equivariant uniform property Gamma for actions of countable discrete groups on C*-algebras that admit traces. In case the group is amenable and the C*-algebra has a compact tracial state space, we prove that this…

Operator Algebras · Mathematics 2025-06-04 Gábor Szabó , Lise Wouters

Let $\alpha : \Gamma \curvearrowright A$ be an action of a discrete group $\Gamma$ on a unital C*-algebra $A$ by *-automorphisms and let $A \rtimes_{\alpha,\lambda} \Gamma$ denote the corresponding reduced crossed product C*-algebra.…

Operator Algebras · Mathematics 2024-06-04 Matthew Kennedy , Dan Ursu

Let B be a unital C*-algebra, let A be a unital subalgebra, and let E be a conditional expectation from B to A with index-finite type and a quasi-basis of n elements. Then the topological stable rank satisfies \tsr (B) \leq \tsr (A) + n -…

Operator Algebras · Mathematics 2007-05-23 Ja A Jeong , Hiroyuki Osaka , N. Christopher Phillips , Tamotsu Teruya

We prove stability theorems in the Cuntz semigroup of a commutative C*-algebra which are analogues of classical stability theorems for topological vector bundles over compact Hausdorff spaces. Several applications to simple unital AH…

Operator Algebras · Mathematics 2014-02-26 Andrew S. Toms

We examine the ranks of operators in semi-finite C*-algebras as measured by their densely defined lower semicontinuous traces. We first prove that a unital simple C*-algebra whose extreme tracial boundary is nonempty and finite contains…

Operator Algebras · Mathematics 2015-06-01 Aaron Tikuisis , Andrew Toms

We introduce a general class of automorphisms of rotation algebras, the noncommutative Furstenberg transformations. We prove that fully irrational noncommutative Furstenberg transformations have the tracial Rokhlin property, which is a…

Operator Algebras · Mathematics 2007-05-23 Hiroyuki Osaka , N. Christopher Phillips

Given a Hausdorff compact space X, we study the C^*-(semi)-norms on the algebraic tensor product $A\otimes_{alg,C(X)} B$ of two C(X)-algebras A and B over C(X). In particular, if one of the two C(X)-algebras defines a continuous field of…

Operator Algebras · Mathematics 2016-09-07 Etienne Blanchard

We study actions of countable discrete amenable groups on unital separable simple nuclear Z-absorbing C*-algebras. Under a certain assumption on tracial states, which is automatically satisfied in the case of a unique tracial state, the…

Operator Algebras · Mathematics 2016-12-28 Yasuhiko Sato

We prove that separable C*-algebras which are completely close in a natural uniform sense have isomorphic Cuntz semigroups, continuing a line of research developed by Kadison - Kastler, Christensen, and Khoshkam. This result has several…

Operator Algebras · Mathematics 2015-08-26 Francesc Perera , Andrew Toms , Stuart White , Wilhelm Winter

This paper explores the following regularity properties and their relationships for simple, not-necessarily-unital C*-algebras: (i) Jiang-Su stability, (ii) Unperforation in the Cuntz semigroup, and (iii) slow dimension growth (applying…

Operator Algebras · Mathematics 2012-07-18 Aaron Tikuisis

We define a broad class of crossed product C*-algebras of the form C(G)xG, where G is a discrete countable amenable residually finite group, and G is a profinite completion of G. We show that they are unital separable simple nuclear…

Operator Algebras · Mathematics 2013-01-22 Stefanos Orfanos

Let $X$ be a finite connected graph, each of whose vertices has degree at least three. The fundamental group $\Gamma$ of $X$ is a free group and acts on the universal covering tree $\Delta$ and on its boundary $\partial \Delta$, endowed…

Operator Algebras · Mathematics 2013-02-25 Guyan Robertson

In this paper we show that the Cuntz--Pimsner algebras associated to minimal homeomorphisms twisted by line bundles, along with their orbit-breaking subalgebras, are $\mathcal{Z}$-stable whenever the underlying dynamical system has the…

Operator Algebras · Mathematics 2025-11-25 Marzieh Forough , Ja A Jeong , Karen R. Strung

Motivated by reformulating Furstenberg's $\times p,\times q$ conjecture via representations of a crossed product $C^*$-algebra, we show that in a discrete $C^*$-dynamical system $(A,\Gamma)$, the space of (ergodic) $\Gamma$-invariant states…

Operator Algebras · Mathematics 2016-03-01 Huichi Huang , Jianchao Wu

Let Gamma be a semidirect product of the form Z^n rtimes Z/p where p is prime and the Z/p-action on Z^n is free away from the origin. We will compute the topological K-theory of the real and complex group C*-algebra of Gamma and show that…

K-Theory and Homology · Mathematics 2015-11-30 James F. Davis , Wolfgang Lueck

Let $A$ be a unital $C^*$-algebra and let $U_0(A)$ be the group of unitaries of $A$ which are path connected to the identity. Denote by $CU(A)$ the closure of the commutator subgroup of $U_0(A).$ Let $i_A^{(1, n)}\colon…

Operator Algebras · Mathematics 2016-01-20 Guihua Gong , Huaxin Lin , Yifeng Xue

Let $G$ be a discrete group. Given unital $G$-$C^*$-algebras $\mathcal{A}$ and $\mathcal{B}$, we give an abstract condition under which every $G$-subalgebra $\mathcal{C}$ of the form $\mathcal{A}\subset \mathcal{C}\subset…

Operator Algebras · Mathematics 2025-06-18 Tattwamasi Amrutam , Yongle Jiang
‹ Prev 1 4 5 6 7 8 10 Next ›