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Related papers: Amenability and the Liouville property

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We provide equivalent conditions for Liouville property of actions of groups. As an application, we show that there is a Liouville measure for the action of the Thompson group $F$ on dyadic rationals. This result should be compared with a…

Group Theory · Mathematics 2016-08-12 Kate Juschenko , Tianyi Zheng

We show that topological amenability of an action of a countable discrete group on a compact space is equivalent to the existence of an invariant mean for the action. We prove also that this is equivalent to vanishing of bounded cohomology…

Group Theory · Mathematics 2010-04-05 Jacek Brodzki , Graham A. Niblo , Piotr Nowak , Nick Wright

We show that amenability of a group acting by homeomorphisms can be deduced from a certain local property of the action and recurrency of the orbital Schreier graphs. This covers amenability of a wide class groups, the amenability of which…

Group Theory · Mathematics 2017-10-05 Kate Juschenko , Volodymyr Nekrashevych , Mikael de la Salle

Let $G$ be a second countable locally compact groupoid equipped with a Haar system $\lambda$.In this work, we introduce and develop the notion of amenability for continuous unitary representations of $G$, formulated in terms of Hilbert…

Operator Algebras · Mathematics 2026-02-13 K. N. Sridharan , N. Shravan Kumar

We study skew-amenable topological groups, i.e., those admitting a left-invariant mean on the space of bounded real-valued functions left-uniformly continuous in the sense of Bourbaki. We prove characterizations of skew-amenability for…

Group Theory · Mathematics 2022-04-22 Kate Juschenko , Friedrich Martin Schneider

We establish that a second countable locally compact groupoid possessing a continuous Haar system is topologically amenable if and only if it is Borel amenable. We give some examples and applications.

Dynamical Systems · Mathematics 2013-04-09 Jean Renault

Let $G$ be a locally compact group and $E$ be a $G$-space. An irreducible probability measure $\mu$ on $G$ is said to have Liouville property on $E$ if $G$-invariant functions on $E$ are the only continuous bounded functions on $E$ that…

Dynamical Systems · Mathematics 2013-12-31 C. R. E. Raja

We prove a characterization of the amenability of countable Borel equivalence relations in terms of the uniform Liouville property for group actions on their classes. Furthermore, inspired by a well-known amenability criterion for locally…

Group Theory · Mathematics 2026-03-10 Maksym Chaudkhari , Kate Juschenko , Friedrich Martin Schneider

The main aim of the present set of notes is to give new, short and essentially self-contained proofs of some classical, as well as more recent, results about random walks on groups. For instance, we shall see that the drift characterization…

Dynamical Systems · Mathematics 2014-07-08 Michael Björklund

We investigate the notion of relatively amenable topological action and show that the action of Thompson's group $T$ on $S^1$ is relatively amenable with respect to Thompson's group $F$. We use this to conclude that $F$ is exact if and only…

Group Theory · Mathematics 2021-09-28 Eduardo Scarparo

We exhibit examples of actions of countable discrete groups on both simple and non-simple nuclear stably finite C*-algebras that are tracially amenable but not amenable. We furthermore obtain that, under the additional assumption of strict…

Operator Algebras · Mathematics 2024-08-21 Eusebio Gardella , Julian Kranz , Andrea Vaccaro

It is shown that the groups of finite energy (that is, Sobolev class $H^1$) paths and loops with values in a compact Lie group are amenable in the sense of Pierre de la Harpe, that is, every continuous action of such a group on a compact…

Functional Analysis · Mathematics 2024-09-05 Vladimir G. Pestov

Let G be one of the local gauge groups C(X,U(n)), C^\infty(X,U(n)), C(X,SU(n)) or C^\infty(X,SU(n)) where X is a compact Riemannian manifold. We observe that G has a nontrivial group topology, coarser than its natural topology, w.r.t. which…

Mathematical Physics · Physics 2008-11-26 Alan Carey , Hendrik Grundling

We prove that amenability of a discrete group is equivalent to dimension flatness of certain ring inclusions naturally associated with measure preserving actions of the group. This provides a group-measure space theoretic solution to a…

Group Theory · Mathematics 2013-05-16 David Kyed , Henrik Densing Petersen

Inner amenability is a bridge between amenability of an object and amenability of its operator algebras. It is an open problem of Ananantharman-Delaroche to decide whether all \'etale groupoids are inner amenable. Approximate lattices and…

Operator Algebras · Mathematics 2023-07-06 Gabriel Favre

We provide a unifying approach which links results on algebraic actions by Lind and Schmidt, Chung and Li, and a topological result by Meyerovitch that relates entropy to the set of asymptotic pairs. In order to do this we introduce a…

Dynamical Systems · Mathematics 2023-07-21 Sebastián Barbieri , Felipe García-Ramos , Hanfeng Li

We introduce a strengthening of the notion of transience for planar maps in order to relax the standard condition of bounded degree appearing in various results, in particular, the existence of Dirichlet harmonic functions proved by…

Combinatorics · Mathematics 2020-04-08 Johannes Carmesin , Agelos Georgakopoulos

We introduce and study various notions of amenability continuous (Borel) partial actions of locally compact (Borel) groups $G$ on topological (standard Borel) spaces. We also study amenability of partial representations of a locally compact…

Dynamical Systems · Mathematics 2022-11-15 Massoud Amini

We study amenability of definable and topological groups. Among our main technical tools is an elaboration on and strengthening of the Massicot-Wagner version of the stabilizer theorem, and some results around measures. As an application we…

Logic · Mathematics 2021-11-23 Ehud Hrushovski , Krzysztof Krupiński , Anand Pillay

We prove that, if a discrete group $G$ is not inner amenable, then the unit group of the ring of operators affiliated with the group von Neumann algebra of $G$ is non-amenable with respect to the topology generated by its rank metric. This…

Operator Algebras · Mathematics 2025-03-04 Friedrich Martin Schneider