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We consider the action of Mandelbrot multiplicative cascades on probability measures supported on a symbolic space. For general probability measures, we obtain almost a sharp criterion of non-degeneracy of the limiting measure; it relies on…

Probability · Mathematics 2021-05-26 Julien Barral , Xiong Jin

We implement GAP functions about groups with action on itself and investigate some basic properties of small groups with action on itself of order $<32$.

Group Theory · Mathematics 2014-10-09 Ahmet Faruk Aslan , Alper Odabaş , Enver Önder Uslu

In this paper we discuss some connections between measurable dynamics and rigidity aspects of group representations and group actions. A new ergodic feature of familiar group boundaries is introduced, and is used to obtain rigidity results…

Dynamical Systems · Mathematics 2014-04-22 Uri Bader , Alex Furman

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 2019-01-25 Andrew Warren

We study invariant probability measures on the homogeneous space $\mathrm{SL}_n(\mathbb R)/\mathrm{SL}_n(\mathbb Z)$ for the action of subgroups of $\mathrm{SL}_n(\mathbb R)$ of the form $SF$ where $F$ is generated by one parameter…

Dynamical Systems · Mathematics 2019-05-16 Manfred Einsiedler , Ronggang Shi

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 generalize results of Jones and Olsen on multi-parameter moving ergodic averages to measure-preserving actions of $\mathbb R^d$ for $d\geq 1$. In particular, we give necessary and sufficient conditions for the pointwise convergence of…

Dynamical Systems · Mathematics 2025-11-07 Jiajun Cheng , Reynold Fregoli , Beinuo Guo

Let $R$ be a ring, let $G$ be an amenable group and let $R\ast G$ be a crossed product. The goal of this paper is to construct, starting with a suitable additive function $L$ on the category of left modules over $R$, an additive function on…

Rings and Algebras · Mathematics 2017-10-24 Simone Virili

We consider actions of completely metrisable groups on simplicial trees in the context of the Bass--Serre theory. Our main result characterises continuity of the amplitude function corresponding to a given action. Under fairly mild…

Group Theory · Mathematics 2010-10-01 Christian Rosendal

We extend in a noncommutative setting the individual ergodic theorem of Nevo and Stein concerning measure preserving actions of free groups and averages on spheres $s_{2n}$ of even radius. Here we study state preserving actions of free…

Operator Algebras · Mathematics 2007-05-23 Claire Anantharaman-Delaroche

In this paper we give some new criteria for identifying the components of a probability measure, in its Lebesgue decomposition. This enables us to give new criteria to identify spectral types of self-adjoint operators on Hilbert spaces,…

Symplectic Geometry · Mathematics 2007-05-23 A Jensen , M Krishna

We study the ergodicity of non-autonomous discrete dynamical systems with non-uniform expansion. As an application we get that any uniformly expanding finitely generated semigroup action of $C^{1+\alpha}$ local diffeomorphisms of a compact…

Dynamical Systems · Mathematics 2018-11-26 Pablo G. Barrientos , Abbas Fakhari

Consider a smooth, locally free, codimension-one action of a higher-rank, simple, split Lie group $G$ on a closed manifold $M$. Let $P$ be a minimal parabolic subgroup of $G$. If the action admits a $P$-invariant probability measure that is…

Dynamical Systems · Mathematics 2025-12-02 Camilo Arosemena Serrato

We prove that for any given modulus of continuity {\omega} there exist (uncountably many) C1 uniformly expanding maps of the circle whose derivatives have $C^1$ as an optimal modulus of continuity and which preserve an invariant probability…

Dynamical Systems · Mathematics 2023-04-26 Hamza Ounesli

We show that every ergodic dynamical system induces a system with pure Lebesgue spectrum of infinite multiplicity.

Dynamical Systems · Mathematics 2024-09-04 Fatna Abdedou , Bassam Fayad , Jean-Paul Thouvenot

We develop a theory of group actions and coverings on Brauer graphs that parallels the theory of group actions and coverings of algebras. In particular, we show that any Brauer graph can be covered by a tower of coverings of Brauer graphs…

Representation Theory · Mathematics 2012-12-03 Edward L Green , Sibylle Schroll , Nicole Snashall

The title refers to the area of research which studies infinite groups using measure-theoretic tools, and studies the restrictions that group structure imposes on ergodic theory of their actions. The paper is a survey of recent developments…

Dynamical Systems · Mathematics 2010-08-10 Alex Furman

We give the basic definitions of group actions on (algebraic) stacks, and prove the existence of fixed points and quotients as (algebraic) stacks.

Algebraic Geometry · Mathematics 2007-05-23 Matthieu Romagny

We prove universal lower bounds for discrepancies (i.e. sizes of spectral gaps of averaging operators) of measure-preserving actions of a locally compact group on probability spaces. For example, a locally compact Hausdorff unimodular group…

Dynamical Systems · Mathematics 2023-03-14 Antoine Pinochet Lobos , Christophe Pittet

Using an approach emerging from the theory of closable derivations on von Neumann algebras, we exhibit a class of groups CR satisfying the following property: given any groups G_1, G_2 in CR, then any free, ergodic, measure preserving…

Operator Algebras · Mathematics 2019-12-19 Ionut Chifan , Jesse Peterson