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Related papers: Amenability of Universal 2-Grigorchuk group

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We prove that every ergodic amenable action of an algebraic group over a local field of characteristic zero is induced from an ergodic action of an amenable subgroup.

Dynamical Systems · Mathematics 2007-05-23 C. R. E. Raja

Amenable groups are those admitting an invariant mean -- a finitely additive probability mean that assigns equal ``weight'' to any two translates of the same set. We introduce coset correct means (CCMs), a class of finitely additive means…

Group Theory · Mathematics 2026-04-21 Armando Martino , Motiejus Valiunas

We observe that a Polish group $G$ is amenable if and only if every continuous action of $G$ on the Hilbert cube admits an invariant probability measure. This generalizes a result of Bogatyi and Fedorchuk. We also show that actions on the…

Group Theory · Mathematics 2011-08-08 Yousef Al-Gadid , Brice R. Mbombo , Vladimir G. Pestov

The original definition of amenability given by von Neumann in the highly non-constructive terms of means was later recast by Day using approximately invariant probability measures. Moreover, as it was conjectured by Furstenberg and proved…

Functional Analysis · Mathematics 2020-05-29 Theo Bühler , Vadim A. Kaimanovich

We define the notion of computability of F{\o}lner sets for finitely generated amenable groups. We prove, by an explicit description, that the Kharlampovich group, a finitely presented solvable group with unsolvable word problem, has…

Group Theory · Mathematics 2018-07-04 Matteo Cavaleri

Let $K$ be a locally compact field of characteristic 0. Let $G$ be a linear algebraic group defined over $K$, acting algebraically on an algebraic variety $V$. We prove that the action of $G(K)$ (the group of $K$-rational points of $G$) on…

Dynamical Systems · Mathematics 2024-05-13 Alain J. Valette

In this article, we investigate some relations between dynamical and algebraic properties of semigroups of entire maps with applications to semigroups of formal series. We show that two entire maps fixing the origin share the set of…

Dynamical Systems · Mathematics 2024-08-12 C. Cabrera , P. Dominguez , P. Makienko

We study amenable minimal Cantor systems of free groups arising from the diagonal actions of the boundary actions and certain Cantor systems. It is shown that every virtually free group admits continuously many amenable minimal Cantor…

Operator Algebras · Mathematics 2017-01-04 Yuhei Suzuki

The goal of this paper is to give a group-theoretic proof of the congruence subgroup property for $Aut(F_2)$, the group of automorphisms of a free group on two generators. This result was first proved by Asada using techniques from…

Group Theory · Mathematics 2011-04-22 Kai-Uwe Bux , Mikhail Ershov , Andrei Rapinchuk

We develop the theory of algorithmic randomness for the space $A^G$ where $A$ is a finite alphabet and $G$ is a computable amenable group. We give an effective version of the Shannon-McMillan-Breiman theorem in this setting. We also extend…

Logic · Mathematics 2018-03-23 Adam R. Day

In this paper we further study links between concentration of measure in topological transformation groups, existence of fixed points, and Ramsey-type theorems for metric spaces. We prove that whenever the group $\Iso(\U)$ of isometries of…

Functional Analysis · Mathematics 2007-09-03 Vladimir Pestov

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

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

We introduce a hierarchy for unital Kirchberg algebras with finitely generated K-groups by which the first and second homotopy groups of the automorphism groups serve as a complete invariant of classification. We also introduce an invariant…

Operator Algebras · Mathematics 2024-09-25 Kengo Matsumoto , Taro Sogabe

We show that a finite group $G$ admitting an automorphism $\alpha$ such that the function $G\rightarrow G$, $g\mapsto g\alpha(g)$, is bijective is necessarily solvable.

Group Theory · Mathematics 2019-11-20 Alexander Bors

We prove that every amenable group of cohomological dimension two whose integral group ring is a domain is solvable and investigate certain homological finiteness properties of groups that satisfy the analytic zero divisor conjecture and…

Group Theory · Mathematics 2016-09-27 Dieter Degrijse

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 investigate recent uniqueness theorems for reduced $C^*$-algebras of Hausdorff \'{e}tale groupoids in the context of inverse semigroups. In many cases the distinguished subalgebra is closely related to the structure of the inverse…

Operator Algebras · Mathematics 2016-11-11 Scott M. LaLonde , David Milan

Let $F$ be a perfect field and $M^*(F)$ the nonassociative simple Moufang loop consisting of the units in the (unique) split octonion algebra $O(F)$ modulo the center. Then $Aut(M^*(F))$ is equal to $G_2(F) \rtimes Aut(F)$. In particular,…

Group Theory · Mathematics 2009-11-13 Gábor P. Nagy , Petr Vojtěchovský

By giving an interesting characterisation of amenable multiplicative unitaries in term of one dimensional representations, we show in a simple way that bicrossproducts of amenable locally compact groups is both amenable and coamenable.

Operator Algebras · Mathematics 2007-05-23 Chi-Keung Ng
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