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Related papers: Scale pressure for amenable group actions

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We show that if $G$ is a countable amenable group, then every stationary non-Gaussian symmetric $\alpha$-stable (S$\alpha$S) process indexed by $G$ is ergodic if and only if it is weakly-mixing, and it is ergodic if and only if its Rosinski…

Probability · Mathematics 2024-05-02 Nachi Avraham-Re'em

In this paper, we investigate the discrete spectrum of probability measures for actions of locally compact groups. We establish that a probability measure has a discrete spectrum if and only if it has bounded measure-max-mean-complexity. As…

Dynamical Systems · Mathematics 2025-01-31 Zongrui Hu , Xiao Ma , Leiye Xu , Xiaomin Zhou

We answer an open question of Grigorchuk and Zuk about amenability using random walks. Our results separate the class of amenable groups from the closure of subexponentially growing groups under the operations of group extension and direct…

Group Theory · Mathematics 2011-11-10 Laurent Bartholdi , Balint Virag

Recently Lewis Bowen introduced a notion of entropy for measure-preserving actions of countable sofic groups admitting a generating measurable partition with finite entropy; and then David Kerr and Hanfeng Li developed an operator-algebraic…

Dynamical Systems · Mathematics 2011-09-16 Guo Hua Zhang

This paper develops a formal theory of musical scales and their harmonic coverings and introduces orbit covers: coverings obtained by translating a fixed subset across a scale via a group action. Orbit covers generalize familiar…

General Mathematics · Mathematics 2026-04-06 Drew Flieder

A novel notion for constructing a well-balanced scheme - a gradient-robust scheme - is introduced and a showcase application for a steady compressible, isothermal Stokes equations is presented. Gradient-robustness means that arbitrary…

Numerical Analysis · Mathematics 2020-06-24 Mine Akbas , Thierry Gallouet , Almut Gassmann , Alexander Linke , Christian Merdon

We prove a measurable version of the Hall marriage theorem for actions of finitely generated abelian groups. In particular, it implies that for free measure-preserving actions of such groups, if two equidistributed measurable sets are…

Logic · Mathematics 2021-07-08 Tomasz Cieśla , Marcin Sabok

The possibility of mass in the context of scale-invariant, generally covariant theories, is discussed. Scale invariance is considered in the context of a gravitational theory where the action, in the first order formalism, is of the form $S…

High Energy Physics - Theory · Physics 2009-11-07 E. I. Guendelman

A measure-scaling quasi-isometry between two connected graphs is a quasi-isometry that is quasi-$\kappa$-to-one in a natural sense for some $\kappa>0$. For non-amenable graphs, all quasi-isometries are quasi-$\kappa$-to-one for any…

Group Theory · Mathematics 2021-05-12 Anthony Genevois , Romain Tessera

Given a locally finite graph $\Gamma$, an amenable subgroup $G$ of graph automorphisms acting freely and almost transitively on its vertices, and a $G$-invariant activity function $\lambda$, consider the free energy $f_G(\Gamma,\lambda)$ of…

Probability · Mathematics 2023-03-02 Raimundo Briceño

We point out the idea that, at small scales, gravity can be described by the standard degrees of freedom of general relativity, plus a scalar particle and a degree of freedom of a new type: the fakeon. This possibility leads to fundamental…

High Energy Physics - Theory · Physics 2020-01-08 Marco Piva

In this paper, we construct a semigroup associated to an action of countable discrete group on a compact Hausdorff space, that can be regarded as a higher dimensional generalization of the type semigroup. Using this generalized type…

Dynamical Systems · Mathematics 2021-07-01 Xin Ma

Let $K$ be a spherically complete field with a non-Archimedean valuation. We define a new version of $K-$amenability for discrete groups and show that the Banach $K-$algebra $l^1(G)$ is amenable iff $G$ is $K-$amenable in our sense.

Functional Analysis · Mathematics 2015-08-28 Yuri Kuzmenko

Let $G,H$ be two countable amenable groups. We introduce the notion of group charts, which gives us a tool to embed an arbitrary $H$-subshift into a $G$-subshift. Using an entropy addition formula derived from this formalism we prove that…

Dynamical Systems · Mathematics 2025-11-07 Sebastián Barbieri

We establish new results and introduce new methods in the theory of measurable orbit equivalence, using bounded cohomology of group representations. Our rigidity statements hold for a wide (uncountable) class of groups arising from negative…

Group Theory · Mathematics 2007-05-23 Nicolas Monod , Yehuda Shalom

Amenable actions of locally compact groups on von Neumann algebras are investigated by exploiting the natural module structure of the crossed product over the Fourier algebra of the acting group. The resulting characterisation of…

Operator Algebras · Mathematics 2021-01-20 Andrew McKee , Reyhaneh Pourshahami

We generalize Berg's notion of quasi-disjointness to actions of countable groups and prove that every measurably distal system is quasi-disjoint from every measure preserving system. As a corollary we obtain easy to check necessary and…

Dynamical Systems · Mathematics 2023-12-19 Joel Moreira , Florian K. Richter , Donald Robertson

By classifying $S$-maximal amenable subgroups of algebraic groups over a global field of characteristic zero, we obtain a complete classification of maximal amenable subgroups up to commensurability in the respective arithmetic groups.…

Group Theory · Mathematics 2022-10-21 Vadim Alekseev , Alessandro Carderi

By combining R{\o}rdam's construction and the author's previous construction, we provide the first examples of amenable actions of non-amenable groups on simple separable nuclear C*-algebras that are neither stably finite nor purely…

Operator Algebras · Mathematics 2025-03-03 Yuhei Suzuki

A continuous action of a group G on a compact metric space has sensitive dependence on initial conditions if there is a number e>0 such that for any open set U we can find g in G such that g.U has diameter greater than e. We prove that if a…

Dynamical Systems · Mathematics 2009-07-16 Fabrizio Polo