English
Related papers

Related papers: A groupoid approach to L\"uck's amenability conjec…

200 papers

We prove that the measure algebra $M(G)$ of a locally compact group $G$ is Connes-amenable if and only if $G$ is amenable.

Functional Analysis · Mathematics 2007-05-23 Volker Runde

In this paper, we introduce actions of fusion algebras on unital $C^*$-algebras, and define amenability for fusion algebraic actions. Motivated by S.\ Neshveyev et al.'s work, considering the co-representation ring of a compact quantum…

Operator Algebras · Mathematics 2021-08-24 Xiao Chen , Debashish Goswami , Huichi Huang

We here consider inner amenability from a geometric and group theoretical perspective. We prove that for every non-elementary action of a group $G$ on a finite dimensional irreducible CAT(0) cube complex, there is a nonempty $G$-invariant…

Group Theory · Mathematics 2021-08-16 Bruno Duchesne , Robin Tucker-Drob , Phillip Wesolek

We study definably amenable NIP groups. We develop a theory of generics, showing that various definitions considered previously coincide, and study invariant measures. Applications include: characterization of regular ergodic measures, a…

Logic · Mathematics 2017-12-21 Artem Chernikov , Pierre Simon

We show that every group $H$ of at most exponential growth with respect to some left invariant metric admits a bi-Lipschitz embedding into a finitely generated group $G$ such that $G$ is amenable (respectively, solvable, satisfies a…

Group Theory · Mathematics 2019-12-19 A. Olshanskii , D. Osin

We introduce the notion of dynamic asymptotic dimension growth for actions of discrete groups on compact spaces, and more generally for locally compact \'etale groupoids. Using the work of Bartels, L\"uck, and Reich, we bridge asymptotic…

Dynamical Systems · Mathematics 2025-02-04 Hang Wang , Yanru Wang , Jianguo Zhang , Dapeng Zhou

Consider an inclusion of diffuse von Neumann algebras A c M . We say that A c M has the absorbing amenability property if for any diffuse subalgebra B c A and any amenable intermediate algebra B c D c M we have that D is contained in A. We…

Operator Algebras · Mathematics 2015-12-16 Arnaud Brothier , Chenxu Wen

We show that an \'etale groupoid which is strongly amenable at infinity is amenable whenever its full and reduced $C^*$-algebras coincide.

Operator Algebras · Mathematics 2022-02-01 Julian Kranz

Let G be a group and let K be a field of characteristic zero. We shall prove that KG can be embedded into a von Neumann unit-regular ring. In the course of the proof, we shall obtain a result relevant to the Atiyah conjecture.

Rings and Algebras · Mathematics 2007-08-17 Peter A. Linnell

Given a discrete measured groupoid $\mathcal{G}$, we study properties of the corresponding von Neumann algebra $L(\mathcal{G})$ using the techniques of Popa's deformation/rigidity theory. More specifically, we define and study the Gaussian…

Operator Algebras · Mathematics 2025-09-19 Felipe Flores , James Harbour

We consider the amenability of groupoids $G$ equipped with a group valued cocycle $c:G\to Q$ with amenable kernel $c^{-1}(e)$. We prove a general result which implies, in particular, that $G$ is amenable whenever $Q$ is amenable and if…

Operator Algebras · Mathematics 2015-03-18 Jean N. Renault , Dana P. Williams

We give a definition of an amenable fusion module over a fusion algebra. A notion of relative integrability for the `coduals' of coideals of compact quantum groups was recently introduced in the joint work of de Commer and Dzokou Talla. We…

Quantum Algebra · Mathematics 2023-11-21 Benjamin Anderson-Sackaney , Leonid Vainerman

We prove that weak amenability of a locally compact group imposes a strong condition on its amenable closed normal subgroups. This extends non weak amenability results of Haagerup (1988) and Ozawa--Popa (2010). A von Neumann algebra…

Operator Algebras · Mathematics 2015-01-14 Narutaka Ozawa

We define a Banach algebra A to be dual if $A = (A_\ast)^\ast$ for a closed submodule $A_\ast$ of $A^\ast$. The class of dual Banach algebras includes all $W^\ast$-algebras, but also all algebras M(G) for locally compact groups G, all…

Functional Analysis · Mathematics 2007-05-23 Volker Runde

In 2005, Abdollahi and Rejali, studied the relations between paradoxical decompositions and configurations for semigroups. In the present paper, we introduce another concept of amenability on semigroups and groups which includes amenability…

Functional Analysis · Mathematics 2015-01-27 Ali Tavakoli , Ali Rejali

We say that an action of a countable discrete inverse semigroup on a locally compact Hausdorff space is amenable if its groupoid of germs is amenable in the sense of Anantharaman-Delaroche and Renault. We then show that for a given inverse…

Operator Algebras · Mathematics 2015-10-14 Ruy Exel , Charles Starling

In this paper, we show that there is a net for amenable transformation groups like F{\o}lner net for amenable groups and investigate amenability of a transformation group constructed by semidirect product of groups. We introduce inner…

Functional Analysis · Mathematics 2026-04-10 Ali Ebadian , Ali Jabbari

We give a definition of amenability at infinity for a locally compact, $\sigma$-compact and Hausdorff etale groupoid and we study in some case the exactness of the reduced $C^*$-algebra of a such groupoid.

Operator Algebras · Mathematics 2014-10-31 Ivan Lassagne

Entropy of measure preserving or continuous actions of amenable discrete groups allows for various equivalent approaches. Among them are the ones given by the techniques developed by Ollagnier and Pinchon on the one hand and the…

Dynamical Systems · Mathematics 2025-04-09 Till Hauser , Friedrich Martin Schneider

Motivated by a result of Ky Fan in 1965, we establish a characterization of a left amenable F-algebra (which includes the group algebra and the Fourier algebra of a locally compact group and quantum group algebras, or more generally the…

Functional Analysis · Mathematics 2014-04-15 Anthony T. -M. Lau , Yong Zhang