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Related papers: Property A for coarse spaces

200 papers

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

The paper introduces the class of O-metric spaces, a novel generalization of metric-type spaces, classifying almost all possible metric types into upward and downward O-metrics. We list some topologies arising from O-metrics and discuss…

General Mathematics · Mathematics 2025-04-29 Hallowed O. Olaoluwa , Aminat O. Ige , Johnson O. Olaleru

We investigate how coarse embeddability of box spaces into Hilbert space behaves under group extensions. In particular, we prove a result which implies that a semidirect product of a finitely generated free group by a finitely generated…

Group Theory · Mathematics 2011-11-29 A. Khukhro

The aim of the article is to provide a characterization of the Haagerup property for locally compact, second countable groups in terms of actions on $\sigma$-finite measure spaces. It is inspired by the very first definition of amenability,…

Group Theory · Mathematics 2020-04-21 Thiebout Delabie , Paul Jolissaint , Alexandre Zumbrunnen

We introduce the notion of coarse metric. Every coarse metric induces a coarse structure on the underlying set. Conversely, we observe that all coarse spaces come from a particular type of coarse metric in a unique way. In the case when the…

Metric Geometry · Mathematics 2020-12-15 Chi-Keung Ng

Inspired by group cohomology, we define several coarse topological invariants of metric spaces. We define the coarse cohomological dimension of a metric space, and demonstrate that if G is a countable group, then the coarse cohomological…

Group Theory · Mathematics 2024-11-08 Alexander Margolis

Metric spaces satisfying properties stronger than completeness and weaker than compactness have been studied by many authors over the years. One such significant family is that of cofinally complete metric spaces. We discuss the…

General Topology · Mathematics 2018-07-12 Lipsy , Manisha Aggarwal , S. Kundu

The question in the title is discussed briefly, with emphasis on a few basic examples and their properties.

Metric Geometry · Mathematics 2007-09-12 Stephen Semmes

We describe a construction (the `warped cone construction') which produces examples of coarse spaces with large groups of translations. We show that by this construction we can obtain many examples of coarse spaces which do not have…

General Topology · Mathematics 2014-11-11 John Roe

In this paper we classify countable locally finite-by-abelian groups up to coarse isomorphism. This classification is derived from a coarse classification of amenable shift-homogeneous metric spaces.

Metric Geometry · Mathematics 2014-12-16 Taras Banakh , Matija Cencelj , Dušan Repovš , Ihor Zarichnyi

We introduced the concept of a metric value set (MVS) in an earlier paper \cite{GM} and developed the idea further in \cite{AS}. In this paper we study locally $M$-metrizable spaces and the products of $M$-metrizable spaces. Finally we…

General Topology · Mathematics 2017-07-04 Olli Hella

We characterise Geometric Property (T) by the existence of a certain projection in the maximal uniform Roe algebra $C_{u,\max}^*(X)$, extending the notion of Kazhdan projection for groups to the realm of metric spaces. We also describe this…

Operator Algebras · Mathematics 2024-09-10 Ignacio Vergara

The connection between the coarse geometry of metric spaces and analytic properties of topological groupoids is well known. One of the main results of Skandalis, Tu and Yu is that a space admits a coarse embedding into Hilbert space if and…

K-Theory and Homology · Mathematics 2014-09-23 Martin Finn-Sell

We show pro-definability of spaces of definable types in various classical complete first order theories, including complete o-minimal theories, Presburger arithmetic, $p$-adically closed fields, real closed and algebraically closed valued…

Logic · Mathematics 2022-08-09 Pablo Cubides Kovacsics , Jinhe Ye

We propose a quantization of coarse spaces and uniform Roe algebras. The objects are based on the quantum relations introduced by N. Weaver and require the choice of a represented von Neumann algebra. In the case of the diagonal inclusion…

Operator Algebras · Mathematics 2025-08-13 Bruno M. Braga , Joseph Eisner , David Sherman

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

We investigate fixed point properties for isometric actions of topological groups on a wide class of metric spaces, with a particular emphasis on Hilbert spaces. Instead of requiring the action to be continuous, we assume that it is…

Group Theory · Mathematics 2022-12-12 Romain Tessera , Jeroen Winkel

We define the concept of a partial translation structure T on a metric space X and we show that there is a natural C*-algebra C*(T) associated with it which is a subalgebra of the uniform Roe algebra C*_u(X). We introduce a coarse invariant…

Operator Algebras · Mathematics 2007-05-23 J. Brodzki , G. A. Niblo , N. J. Wright

We introduce a notion of topological property (T) for \'etale groupoids. This simultaneously generalizes Kazhdan's property (T) for groups and geometric property (T) for coarse spaces. One main goal is to use this property (T) to prove the…

Operator Algebras · Mathematics 2021-01-12 Clément Dell'Aiera , Rufus Willett

In this series of papers, we study correspondence between the following: (1) large scale structure of the metric space bigsqcup_m {Cay(G(m))} consisting of Cayley graphs of finite groups with k generators; (2) structure of groups which…

Operator Algebras · Mathematics 2015-05-26 Masato Mimura , Narutaka Ozawa , Hiroki Sako , Yuhei Suzuki