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Related papers: Soficity, amenability, and dynamical entropy

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In this paper, we introduce topological pressure for continuous actions of countable sofic groups on compact metrizable spaces. This generalizes the classical topological pressure for continuous actions of countable amenable groups on such…

Dynamical Systems · Mathematics 2012-05-30 Nhan-Phu Chung

Packing topological entropy is a dynamical analogy of the packing dimension, which can be viewed as a counterpart of Bowen topological entropy. In the present paper, we will give a systematically study to the packing topological entropy for…

Dynamical Systems · Mathematics 2021-09-29 Dou Dou , Dongmei Zheng , Xiaomin Zhou

We prove that a topologically predictable action of a countable amenable group has zero topological entropy, as conjectured by Hochman. On route, we investigate invariant random orders and formulate a unified Kieffer-Pinsker formula for the…

Dynamical Systems · Mathematics 2019-02-06 Andrei Alpeev , Tom Meyerovitch , Sieye Ryu

We show that, for countable sofic groups, a Bernoulli action with infinite entropy base has infinite entropy with respect to every sofic approximation sequence. This builds on the work of Lewis Bowen in the case of finite entropy base and…

Dynamical Systems · Mathematics 2010-05-28 David Kerr , Hanfeng Li

Kolmogorov-Sinai entropy is an invariant of measure-preserving actions of the group of integers that is central to classification theory. There are two recently developed invariants, sofic entropy and Rokhlin entropy, that generalize…

Dynamical Systems · Mathematics 2020-11-25 Lewis Bowen

We study a measure entropy for finitely generated free group actions called f-invariant entropy. The f-invariant entropy was developed by Lewis Bowen and is essentially a special case of his measure entropy theory for actions of sofic…

Dynamical Systems · Mathematics 2012-06-27 Brandon Seward

We study smooth actions by lattices in higher-rank simple Lie groups. Assuming one element of the action acts with positive topological entropy, we prove a number of new rigidity results. For lattices in $\mathrm{SL}(n,\mathbb{R})$ acting…

Dynamical Systems · Mathematics 2025-01-24 Aaron Brown , Homin Lee

We introduce a notion of entropy for automorphisms of discrete groups which admit amenable actions on a compact space. This entropy is dual to classical topological entropy in the sense that if G is discrete and abelian then our notion of…

Operator Algebras · Mathematics 2007-05-23 N. P. Brown , E. Germain

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 study a notion of entropy for probability measure preserving actions of finitely generated free groups, called f-invariant entropy, introduced by Lewis Bowen. In the degenerate case, the f-invariant entropy is negative infinity. In this…

Dynamical Systems · Mathematics 2015-01-15 Brandon Seward

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

In this paper, we study several finite approximation properties of topological full groups of group actions on the Cantor set such that free points are dense. Firstly, we establish that for such a distal action $\alpha$ of a countable…

Dynamical Systems · Mathematics 2024-03-07 Xin Ma

Previous work introduced two measure-conjugacy invariants: the $f$-invariant (for actions of free groups) and $\Sigma$-entropy (for actions of sofic groups). The purpose of this paper is to show that the $f$-invariant is a special case of…

Dynamical Systems · Mathematics 2009-07-13 Lewis Bowen

We continue our study of when topological and measure-theoretic entropy agree for algebraic action of sofic groups. Specifically, we provide a new abstract method to prove that an algebraic action is strongly sofic. The method is based on…

Dynamical Systems · Mathematics 2018-11-15 Ben Hayes

A probability measure is a characteristic measure of a topological dynamical system if it is invariant to the automorphism group of the system. We show that zero entropy shifts always admit characteristic measures. We use similar techniques…

Dynamical Systems · Mathematics 2021-07-01 Joshua Frisch , Omer Tamuz

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

In this article we develop a notion of soficity for actions of countable groups on sets. We show two equivalent perspectives, several natural properties and examples. Notable examples include arbitrary actions of both amenable groups and…

Group Theory · Mathematics 2025-08-29 David Gao , Srivatsav Kunnawalkam Elayavalli , Gregory Patchell

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

Let $\Gamma$ be a sofic group with a copy of $\mathbb{Z}$ in its center. We construct an uncountable family of pairwise nonisomorphic measure-preserving $\Gamma$ actions with completely positive entropy, none of which is a factor of a…

Dynamical Systems · Mathematics 2016-04-04 Peter Burton

The $f$-invariant is an isomorphism invariant of free-group measure-preserving actions introduced by Lewis Bowen in [arXiv:0802.4294], where it was used to show that two finite-entropy Bernoulli shifts over a finitely generated free group…

Dynamical Systems · Mathematics 2021-03-02 Christopher Shriver