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Related papers: Pointwise ergodic theorems beyond amenable groups

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We study fluctuations of ergodic averages generated by actions of amenable groups. In the setting of an abstract ergodic theorem for locally compact second countable amenable groups acting on uniformly convex Banach spaces, we deduce a…

Dynamical Systems · Mathematics 2021-10-04 Andrew Warren

We prove a multidimensional ergodic theorem with weighted averages for the action of the group $\mathbb{Z}^d$ on a probability space. At level $n$ weights are of the form $n^{-d} \psi(j/n)$, $ j\in \mathbb{Z}^d$, for real functions $\psi$…

Probability · Mathematics 2024-11-19 A. Faggionato

We study in this paper the validity of the mean ergodic theorem along \emph{left} F\o lner sequences in a countable amenable group $G$. Although the \emph{weak} ergodic theorem always holds along \emph{any} left F\o lner sequence in $G$, we…

Dynamical Systems · Mathematics 2014-08-29 Michael Björklund , Alexander Fish

We prove a new weak mean ergodic theorem (Theorem A) for 1-cocycles associated to weakly mixing representations of amenable groups. Let $G$ be a finitely generated, discrete, amenable group $G$ which admits a controlled Folner sequence. We…

Group Theory · Mathematics 2012-08-06 Ionut Chifan , Thomas Sinclair

In this paper, we first prove the variational principle for amenable packing topological pressure. Then we obtain an inequality concerning amenable packing pressure for factor maps. Finally, we show that the equality about packing…

Dynamical Systems · Mathematics 2024-05-27 Ziqing Ding , Ercai Chen , Xiaoyao Zhou

Using tools from the theory of optimal transport, we establish several results concerning isometric actions of amenable topological groups with potentially unbounded orbits. Specifically, suppose $d$ is a compatible left-invariant metric on…

Functional Analysis · Mathematics 2025-09-16 Christian Rosendal

In the current paper we attempt to transfer the notion of the projectional entropy, originally defined for multidimensional subshifts, to the case of actions of amenable groups. The main theorem states that if a system is strongly…

Dynamical Systems · Mathematics 2024-03-05 Michał Prusik

Given any amenable group $G$ (with a left Haar measure $|\cdot|$ or $dg$), we can select out a \textit{F{\o}lner subnet} $\{F_\theta,\theta\in\Theta\}$ from any left F{\o}lner net in $G$, which is \textit{$L^\infty$-admissible}, namely, for…

Dynamical Systems · Mathematics 2016-06-17 Xiongping Dai

In this short note we study the entropy for algebraic actions of certain amenable groups. The possible values for this entropy are studied. Various fundamental results about certain classes of amenable groups are reproved using elementary…

Dynamical Systems · Mathematics 2013-03-15 Nhan-Phu Chung , Andreas Thom

We show that every free continuous action of a countably infinite elementary amenable group on a finite-dimensional compact metrizable space is almost finite. As a consequence, the crossed products of minimal such actions are…

Dynamical Systems · Mathematics 2026-04-22 David Kerr , Petr Naryshkin

We establish pointwise almost everywhere convergence for ergodic averages along polynomial sequences in nilpotent groups of step two of measure-preserving transformations on $\sigma$-finite measure spaces. We also establish corresponding…

Dynamical Systems · Mathematics 2022-09-07 Alexandru D. Ionescu , Ákos Magyar , Mariusz Mirek , Tomasz Z. Szarek

Let $\Gamma$ be a countably infinite group. A common theme in ergodic theory is to start with a probability measure-preserving (p.m.p.) action $\Gamma \curvearrowright (X, \mu)$ and a map $f \in L^1(X, \mu)$, and to compare the global…

Dynamical Systems · Mathematics 2019-03-14 Anton Bernshteyn

We unify and extend some previous results about cubic ergodic averages and sets of positive density in products of groups. This provides a joint generalization of earlier work of the author in the case of two commuting actions of an…

Dynamical Systems · Mathematics 2008-12-11 John T. Griesmer

Using the continuous decomposition, we classify strongly free actions of discrete amenable groups on strongly amenable subfactors of type III$_\lambda, 0 < \lambda < 1$. Winsl{\o}w's fundamental homomorphism is a complete invariant. This…

funct-an · Mathematics 2008-02-03 Toshihiko Masuda

Extensive amenability is a property of group actions which has recently been used as a tool to prove amenability of groups. We study this property and prove that it is preserved under a very general construction of semidirect products. As…

Group Theory · Mathematics 2021-03-26 Kate Juschenko , Nicolás Matte Bon , Nicolas Monod , Mikael de la Salle

A recent result of Frantzikinakis establishes sufficient conditions for joint ergodicity in the setting of $\mathbb{Z}$-actions. We generalize this result for actions of second-countable locally compact abelian groups. We obtain two…

Dynamical Systems · Mathematics 2022-06-14 Andrew Best , Andreu Ferré Moragues

We prove an analog of Rudolph's theorem for actions of countable amenable groups, which asserts that among invariant measures with entropy at least c on the $G$-shift $(\Lambda^G,\sigma)$, a typical measure has entropy $c$ and is Bernoulli.…

Dynamical Systems · Mathematics 2026-01-07 Tomasz Downarowicz , Jean-Paul Thouvenot , Benjamin Weiss

We say that a countable group $G$ is McDuff if it admits a free ergodic probability measure preserving action such that the crossed product is a McDuff II_1 factor. Similarly, $G$ is said to be stable if it admits such an action with the…

Operator Algebras · Mathematics 2018-09-17 Tobe Deprez , Stefaan Vaes

In this work, we address ergodicity of smooth actions of finitely generated semi-groups on an m-dimensional closed manifold M. We provide sufficient conditions for such an action to be ergodic with respect to the Lebesgue measure. Our…

Dynamical Systems · Mathematics 2015-05-14 Azam Ehsani , Fatome-Helen Ghane , Marzie Zaj

We show that for any countable amenable group action, along F{\o}lner sequences that have for any $c>1$ a two sided $c$-tempered tail, one have universal estimate for the probability that there are $n$ fluctuations in the ergodic averages…

Dynamical Systems · Mathematics 2019-02-22 Uri Gabor