English
Related papers

Related papers: Divisibility and Real Rank Zero

200 papers

We define a "tracial" analog of the Rokhlin property for actions of second countable compact groups on infinite dimensional simple separable unital C*-algebras. We prove that fixed point algebras under such actions (and, in the appropriate…

Operator Algebras · Mathematics 2022-06-20 Javad Mohammadkarimi , N. Christopher Phillips

The goal of this paper is to study when uniform Roe algebras have certain $C^*$-algebraic properties in terms of the underlying space: in particular, we study properties like having stable rank one or real rank zero that are thought of as…

Operator Algebras · Mathematics 2018-01-31 Kang Li , Rufus Willett

In the program to classify C$^*$-algebras, it is very important to find abstract conditions which are sufficient to imply that a given algebra has tracial rank zero, in the sense of Huaxin Lin. Even in the presence of a unique trace, we…

Operator Algebras · Mathematics 2007-05-23 Nathanial P. Brown

A trace on a C*-algebra is amenable (resp. quasidiagonal) if it admits a net of completely positive, contractive maps into matrix algebras which approximately preserve the trace and are approximately multiplicative in the 2-norm (resp.…

Operator Algebras · Mathematics 2018-01-12 Christopher Schafhauser

For any (unital) exchange ring $R$ whose finitely generated projective modules satisfy the separative cancellation property ($A\oplus A\cong A\oplus B\cong B\oplus B$ implies $A\cong B$), it is shown that all invertible square matrices over…

Rings and Algebras · Mathematics 2007-05-23 P. Ara , K. R. Goodearl , K. C. O'Meara , R. Raphael

Let G be a reductive linear algebraic group over an algebraically closed field of characteristic p > 0. A subgroup of G is said to be separable in G if its global and infinitesimal centralizers have the same dimension. We study the…

Group Theory · Mathematics 2008-08-12 Michael Bate , Benjamin Martin , Gerhard Roehrle , Rudolf Tange

We study a pair of $C^*$-algebras by associating a $*$-homomorphism from $A$ to $B$ allowing an approximate left-inverse to the sequence algebra of $A$ in a manner reminiscent of several tracial approximation properties. We are particularly…

Operator Algebras · Mathematics 2022-07-06 Hyun Ho Lee , Hiroyuki Osaka

We show that a ring $R$ is regular if $Tor_{i}^{R}(R^{+},k) = 0$ for some $i\geq 1$ assuming further that $R$ is a $\mathbb{N}$-graded ring of dimension $2$ finitely generated over an equi-characteristic zero field $k$. This answers a…

Commutative Algebra · Mathematics 2022-12-20 Shravan Patankar

Let A be a simple, sigma-unital, non-unital C*-algebra, with metrizable tracial simplex T(A), which is projection-surjective and injective and has strict comparison of positive elements by traces. Then the following are equivalent: (i) A…

Operator Algebras · Mathematics 2018-04-10 Victor Kaftal , P. W. Ng , Shuang Zhang

In this paper we discuss the relationship between direct products of monounary algebras and their components, with respect to the properties of residual finiteness, strong/weak subalgebra separability, and complete separability. For each of…

Rings and Algebras · Mathematics 2021-03-26 Bill de Witt

Let A be a unital simple separable C*-algebra. If $A$ is nuclear and infinite-dimensional, it is known that strict comparison is equivalent to Z-stability if the extreme boundary of its tracial state space is non-empty, compact and of…

Operator Algebras · Mathematics 2014-06-30 Wei Zhang

It is shown that a unital C*-algebra A has the Dixmier property if and only if it is weakly central and satisfies certain tracial conditions. This generalises the Haagerup-Zsido theorem for simple C*-algebras. We also study a uniform…

Operator Algebras · Mathematics 2017-07-18 Robert Archbold , Leonel Robert , Aaron Tikuisis

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

As a follow-up to a paper of D. Petz and J. Zem\'anek [4], a number of equivalent conditions which characterize the trace among linear functionals on matrix algebras, finite rank operators and the socle elements of semisimple Banach…

Functional Analysis · Mathematics 2018-08-21 Gareth Braatvedt , Rudi Brits , Francois Schulz

Let $\Theta=(\theta_{j,k})_{3\times 3}$ be a non-degenerate real skew-symmetric $3\times 3$ matrix, where $\theta_{j,k}\in [0,1).$ For any $\varepsilon>0$, we prove that there exists $\delta>0$ satisfying the following: if $v_1,v_2,v_3$ are…

Operator Algebras · Mathematics 2020-05-20 Jiajie Hua , Qingyun Wang

Let A be a unital separable simple C*-algebra such that either (1) A has real rank zero, strict comparison and cancellation or (2) A is TAI. We study the kernel of the de la Harpe--Skandalis determinant on GL^0(A), proving that the…

Operator Algebras · Mathematics 2012-06-28 P. W. Ng

A countable discrete group $\Gamma$ is said to have the relative ISR-property if for every non-trivial normal subgroup $N\trianglelefteq\Gamma$ and every von Neumann subalgebra $\mathcal{M}\subseteq L(\Gamma)$ invariant under conjugation by…

Operator Algebras · Mathematics 2026-04-07 Tattwamasi Amrutam

This paper is concerned with developing a theory of traces for functions that are integrable but need not possess any differentiability within their domain. Moreover, the domain can have an irregular boundary with cusp-like features and…

Analysis of PDEs · Mathematics 2020-07-07 Mikil Foss

Let $G$ be a real algebraic group defined over $\mathbb{Q}$, $\Gamma$ be an arithmetic subgroup of $G$, and $T$ be a maximal $\mathbb{R}$-split torus. A trajectory in $G/\Gamma$ is divergent if eventually it leaves every compact subset. In…

Dynamical Systems · Mathematics 2019-08-14 Nattalie Tamam

We investigate the notion of tracial $\mathcal Z$-stability beyond unital C*-algebras, and we prove that this notion is equivalent to $\mathcal Z$-stability in the class of separable simple nuclear C*-algebras.

Operator Algebras · Mathematics 2023-04-05 Jorge Castillejos , Kang Li , Gabor Szabo