English
Related papers

Related papers: Computable Folner sequences of amenable groups

200 papers

Over each nontrivial finite group $G$, there exists a finite system of equations having no solutions in larger finite groups but having a solution in a periodic group containing $G$. We prove several similar facts about amenable, orderable,…

Group Theory · Mathematics 2025-03-04 Alexander Buturlakin , Anton Klyachko , Denis Osin

The first group of results of this paper concerns the compressibility of finite subgroups of the Cremona groups. The second concerns the embeddability of other groups in the Cremona groups and, conversely, the Cremona groups in other…

Algebraic Geometry · Mathematics 2020-01-08 Vladimir L. Popov

We study a new notion of reduction between structures called enumerable functors related to the recently investigated notion of computable functors. Our main result shows that enumerable functors and effective interpretability with the…

Logic · Mathematics 2017-08-11 Dino Rossegger

The aim of this paper is to present an elementary computable theory of random variables, based on the approach to probability via valuations. The theory is based on a type of lower-measurable sets, which are controlled limits of open sets,…

Logic in Computer Science · Computer Science 2021-01-05 Pieter Collins

We introduce and study several amenability properties for unitary corepresentations and *-representations of algebraic quantum groups, which may be used to characterize amenability or co-amenability of such groups. As a background for this…

Operator Algebras · Mathematics 2007-05-23 E. Bedos , R. Conti , L. Tuset

Random graph models are frequently used as a controllable and versatile data source for experimental campaigns in various research fields. Generating such data-sets at scale is a non-trivial task as it requires design decisions typically…

Data Structures and Algorithms · Computer Science 2020-03-03 Manuel Penschuck , Ulrik Brandes , Michael Hamann , Sebastian Lamm , Ulrich Meyer , Ilya Safro , Peter Sanders , Christian Schulz

We show that locally solvable subgroups of PLo(I) are countable. Then for each countable ordered set, we construct a locally solvable subgroup of Thompson's Group F. We develop machinery for understanding embeddings from solvable subgroups…

Group Theory · Mathematics 2018-05-23 Amanda Taylor

In this paper, a group is called weakly amenable if its left regular representation is not uniformly isolated from the trivial representation. First examples of finitely generated non-amenable weakly amenable groups are constructed.

Group Theory · Mathematics 2016-09-14 D. Osin

We investigate the connection between the abelian rank of a countable amenable group and the existence of good averaging sequences (e.g. for the pointwise ergodic theorem). We show that if $G$ is a group of abelian rank $r(G)$ then any…

Dynamical Systems · Mathematics 2014-09-23 Michael Hochman

This paper continues math.GR/0608302's study of amenability of affine algebras (based on the notion of almost-invariant finite-dimensional subspace), and applies it to graded algebras associated with finitely generated groups. Due to a…

Group Theory · Mathematics 2008-04-02 Laurent Bartholdi

We investigate what it means for a (Hausdorff, second-countable) topological group to be computable. We compare several potential definitions in the literature. We relate these notions with the well-established definitions of effective…

Logic · Mathematics 2025-04-16 Heer Tern Koh , Alexander Melnikov , Keng Meng Ng

We provide new computations in bounded cohomology: A group is boundedly acyclic if its bounded cohomology with trivial real coefficients is zero in all positive degrees. We show that there exists a continuum of finitely generated…

Group Theory · Mathematics 2022-10-24 Francesco Fournier-Facio , Clara Loeh , Marco Moraschini

In the present paper our main objective is to extend the notion of $D$-sets in countable amenable groups and to discuss its connection with weak mixing for amenable group actions. Further we prove that *-notions are equivalent in the…

Dynamical Systems · Mathematics 2014-09-30 Dibyendu De , Pintu Debnath

We investigate character degree graphs of solvable groups. In particular, we provide general results that can be used to eliminate which degree graphs can occur as solvable groups. Finally, we show a specific family of graphs cannot occur…

Representation Theory · Mathematics 2024-02-28 Mark W. Bissler , Jacob Laubacher , Mark L. Lewis

We give a complete characterization of countable primitive groups in several settings including linear groups, subgroups of mapping class groups, groups acting minimally on trees and convergence groups. The latter category includes as a…

Group Theory · Mathematics 2007-05-23 Tsachik Gelander , Yair Glasner

The purpose of this article is to extend the earliest results of A.A. Brudno, connecting topological entropy of a subshift X over $\mathbb{N}$ to the Kolmogorov complexity of words in X, to subshifts over computable groups that posses…

Dynamical Systems · Mathematics 2015-10-14 Nikita Moriakov

We study the degrees of selector functions related to the degrees in which a rigid computable structure is relatively computably categorical. It is proved that for some structures such degrees can be represented as the unions of upper cones…

Logic · Mathematics 2023-05-31 I. Sh. Kalimullin

Uniformly finite homology is a coarse invariant for metric spaces; in particular, it is a quasi-isometry invariant for finitely generated groups. In this article, we study uniformly finite homology of finitely generated amenable groups and…

Group Theory · Mathematics 2016-01-20 Matthias Blank , Francesca Diana

In this note, we construct torsion-free countable, amenable, weakly mixing groups, which answer a question of V. Bergelson. Some results related to verbal subgroups and crystallographic groups are also presented.

Dynamical Systems · Mathematics 2016-07-04 Rostislav Grigorchuk , Rostyslav Kravchenko , Alexander Olshanskii

We show that the automorphism groups of countably categorical linear orders are extremely amenable. Using methods of Kechris, Pestov, and Todorcevic, we use this fact to derive a structural Ramsey theorem for certain families of finite…

Logic · Mathematics 2014-02-17 François G. Dorais , Steven Gubkin , Daniel McDonald , Manuel Rivera