English
Related papers

Related papers: Measured asymptotic expanders and rigidity for Roe…

200 papers

In this paper, we use geometric tools to study the structure of asymptotic expanders and show that a sequence of asymptotic expanders always admits a "uniform exhaustion by expanders". It follows that asymptotic expanders cannot be coarsely…

Metric Geometry · Mathematics 2021-10-06 Ana Khukhro , Kang Li , Federico Vigolo , Jiawen Zhang

In this paper, we connect the rigidity problem and the coarse Baum-Connes conjecture for Roe algebras. In particular, we show that if $X$ and $Y$ are two uniformly locally finite metric spaces such that their Roe algebras are…

Operator Algebras · Mathematics 2020-08-06 Bruno de Mendonça Braga , Yeong Chyuan Chung , Kang Li

Roe algebras are C*-algebras built using large-scale (or 'coarse') aspects of a metric space (X,d). In the special case that X=G is a finitely generated group and d is a word metric, the simplest Roe algebra associated to (G,d) is…

Operator Algebras · Mathematics 2013-09-24 Jan Spakula , Rufus Willett

In this memoir we develop a framework to study rigidity problems for Roe-like C*-algebras of countably generated coarse spaces. The main goal is to give a complete and self-contained solution to the problem of C*-rigidity for proper…

Operator Algebras · Mathematics 2025-03-11 Diego Martínez , Federico Vigolo

We generalize all known results on rigidity of uniform Roe algebras to the setting of arbitrary uniformly locally finite coarse spaces. For instance, we show that isomorphism between uniform Roe algebras of uniformly locally finite coarse…

Operator Algebras · Mathematics 2020-07-29 Bruno de Mendonça Braga , Ilijas Farah , Alessandro Vignati

Given a coarse space $(X,\mathcal{E})$, one can define a $\mathrm{C}^*$-algebra $\mathrm{C}^*_u(X)$ called the uniform Roe algebra of $(X,\mathcal{E})$. It has been proved by J. \v{S}pakula and R. Willett that if the uniform Roe algebras of…

Operator Algebras · Mathematics 2020-07-22 Bruno de Mendonça Braga , Ilijas Farah

In this paper, we study the relation between the uniform Roe algebra and the uniform quasi-local algebra associated to a metric space of bounded geometry. In the process, we introduce a weakening of the notion of expanders, called…

Operator Algebras · Mathematics 2020-04-02 Kang Li , Piotr Nowak , Ján Špakula , Jiawen Zhang

We prove that uniformly locally finite metric spaces with isomorphic Roe algebras must be coarsely equivalent. As an application, we also prove that the outer automorphism group of the Roe algebra of a metric space of bounded geometry is…

Operator Algebras · Mathematics 2025-03-10 Diego Martínez , Federico Vigolo

We investigate the rigidity of the $\ell^p$ analog of Roe-type algebras. In particular, we show that if $p\in[1,\infty)\setminus\{2\}$, then an isometric isomorphism between the $\ell^p$ uniform Roe algebras of two metric spaces with…

Operator Algebras · Mathematics 2018-09-05 Yeong Chyuan Chung , Kang Li

In this paper, we study the rigidity of uniform Roe algebras via the ideal structures. We showed that for given metric spaces X and Y with bounded geometry, if their uniform Roe algebras are isomorphic, then they are coarse equivalent.

Operator Algebras · Mathematics 2016-06-03 Qinggang Ren

We show that if $X$ and $Y$ are uniformly locally finite metric spaces whose uniform Roe algebras, $\cstu(X)$ and $\cstu(Y)$, are isomorphic as \cstar-algebras, then $X$ and $Y$ are coarsely equivalent metric spaces. Moreover, we show that…

In this paper, we introduce a notion of expansion for groupoids, which recovers the classical notion of expander graphs by a family of pair groupoids and expanding actions in measure by transformation groupoids. We also consider an…

Operator Algebras · Mathematics 2025-06-23 Xulong Lu , Qin Wang , Jiawen Zhang

In this paper, we conduct further studies on geometric and analytic properties of asymptotic expansion in measure. More precisely, we develop a machinery of Markov expansion and obtain an associated structure theorem for asymptotically…

Dynamical Systems · Mathematics 2022-12-21 Kang Li , Federico Vigolo , Jiawen Zhang

We solve the rigidity problem for uniform Roe algebras, by showing that two uniformly locally finite metric spaces with isomorphic uniform Roe algebras are bijectively coarsely equivalent.

Operator Algebras · Mathematics 2026-02-03 Alessandro Vignati

Gong, Wang and Yu introduced a maximal, or universal, version of the Roe C*-algebra associated to a metric space. We study the relationship between this maximal Roe algebra and the usual version, in both the uniform and non-uniform cases.…

K-Theory and Homology · Mathematics 2011-10-10 Jan Spakula , Rufus Willett

Let $X$ be a discrete metric space with bounded geometry. We show that if $X$ admits an "A-by-CE coarse fibration", then the canonical quotient map $\lambda: C^*_{\max}(X)\to C^*(X)$ from the maximal Roe algebra to the Roe algebra of $X$,…

Operator Algebras · Mathematics 2021-11-12 Liang Guo , Zheng Luo , Qin Wang , Yazhou Zhang

Let X be a proper metric space, which has finite asymptotic dimension in the sense of Gromov (or more generally, straight finite decomposition complexity of Dranishnikov and Zarichnyi). New descriptions are provided of the Roe algebra of X:…

Operator Algebras · Mathematics 2019-03-06 Jan Spakula , Aaron Tikuisis

In this paper, we study embeddings of uniform Roe algebras. Generally speaking, given metric spaces $X$ and $Y$, we are interested in which large scale geometric properties are stable under embedding of the uniform Roe algebra of $X$ into…

Operator Algebras · Mathematics 2019-06-28 Bruno de Mendonça Braga , Ilijas Farah , Alessandro Vignati

We consider operators on $L^2$ spaces that expand the support of vectors in a manner controlled by some constraint function. The primary objects of study are $\mathrm C^*$-algebras that arise from suitable families of constraints, which we…

Operator Algebras · Mathematics 2022-11-08 Bruno de Mendonça Braga , Joseph Eisner , David Sherman

We study embeddings of uniform Roe algebras which have "large range" in their codomain and the relation of those with coarse quotients between metric spaces. Among other results, we show that if $Y$ has property A and there is an embedding…

Operator Algebras · Mathematics 2021-08-27 Bruno de Mendonça Braga
‹ Prev 1 2 3 10 Next ›