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Related papers: A refinement of bounded cohomology

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This paper demonstrates the uniformly finite homology developed by Block and Weinberger and its relationship to amenable spaces via applications to the Cayley graph of Thompson's Group F. In particular, a certain class of subgraph of F is…

Group Theory · Mathematics 2009-03-11 Dan Staley

We study continuous bounded cohomology of totally disconnected locally compact groups with coefficients in a non-Archimedean valued field $K$. To capture the features of classical amenability that induce the vanishing of real bounded…

Group Theory · Mathematics 2022-04-29 Francesco Fournier-Facio

We prove the vanishing of the bounded cohomology of lamplighter groups for a wide range of coefficients. This implies the same vanishing for a number of groups with self-similarity properties, such as Thompson's group F. In particular,…

Group Theory · Mathematics 2021-12-28 Nicolas Monod

We give a new perspective on the homological characterisations of amenability given by Johnson in the context of bounded cohomology and by Block and Weinberger in the context of uniformly finite homology. We examine the interaction between…

Group Theory · Mathematics 2010-03-15 Jacek Brodzki , Graham A. Niblo , Nick Wright

We introduce a bounded version of Bredon cohomology for groups relative to a family of subgroups. Our theory generalizes bounded cohomology and differs from Mineyev--Yaman's relative bounded cohomology for pairs. We obtain cohomological…

Group Theory · Mathematics 2023-05-17 Kevin Li

We define a family of groups that generalises Thompson's groups $T$ and $G$ and also those of Higman, Stein and Brin. For groups in this family we descrine centralisers of finite subgroups and show, that for a given finite subgroup $Q$,…

Group Theory · Mathematics 2013-09-10 Conchita Martinez-Perez , Brita E. A. Nucinkis

A group is boundedly acyclic if its bounded cohomology with trivial real coefficients vanishes in all positive degrees. Amenable groups are boundedly acyclic, while the first non-amenable examples were the group of compactly supported…

Group Theory · Mathematics 2022-06-14 Francesco Fournier-Facio , Clara Loeh , Marco Moraschini

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

We demonstrate the existence of a family of finitely generated subgroups of Richard Thompson's group $F$ which is strictly well-ordered by the embeddability relation in type $\epsilon_0 +1$. All except the maximum element of this family…

Group Theory · Mathematics 2021-02-09 Collin Bleak , Matthew G. Brin , Justin Tatch Moore

We study quasimorphisms and bounded cohomology of a variety of braided versions of Thompson groups. Our first main result is that the Brin--Dehornoy braided Thompson group $bV$ has an infinite-dimensional space of quasimorphisms and thus…

Group Theory · Mathematics 2024-07-10 Francesco Fournier-Facio , Yash Lodha , Matthew C. B. Zaremsky

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

We prove the vanishing of bounded cohomology of the groups acting on trees with almost prescribed local actions $G(F, F')$, where $F<F'$ are finite permutation groups such that $F'$ is 2-transitive. By contrast, when $F'$ is not…

Group Theory · Mathematics 2024-12-31 Giuseppe Bargagnati , Elena Bogliolo

We study the bounded fundamental class in the top dimensional bounded cohomology of negatively curved manifolds with infinite volume. We prove that the bounded fundamental class of $M$ vanishes if $M$ is geometrically finite. Furthermore,…

Geometric Topology · Mathematics 2011-11-29 Sungwoon Kim , Inkang Kim

The purpose of this note is to provide exposition for a proof of the statement in the title. This idea, that arbitrary cohomology classes (of high enough degree) of a finite group $G$ can be trivialized in a finite group extension, has been…

Group Theory · Mathematics 2026-01-09 Adrien DeLazzer Meunier

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

We point out a simple characterisation of topological amenability in terms of bounded cohomology, following Johnson's reformulation of amenability.

Group Theory · Mathematics 2012-07-10 Nicolas Monod

Coboundary expansion (with $\mathbb{F}_2$ coefficients), and variations on it, have been the focus of intensive research in the last two decades. It was used to study random complexes, property testing, and above all Gromov's topological…

Group Theory · Mathematics 2024-04-02 Michael Chapman , Alexander Lubotzky

We provide new vanishing and glueing results for relative simplicial volume, following up on two current themes in bounded cohomology: The passage from amenable groups to boundedly acyclic groups and the use of equivariant topology. More…

Algebraic Topology · Mathematics 2022-02-14 Kevin Li , Clara Loeh , Marco Moraschini

We provide a new characterization of amenability for countable groups, based on frame representations admitting almost invariant vectors. By relaxing the frame inequalities, thereby weakening amenability, we obtain a large class of…

Group Theory · Mathematics 2025-12-03 Dorin Ervin Dutkay , Catalin Georgescu , Gabriel Picioroaga

We study the bounded cohomology of certain groups acting on the Cantor set. More specifically, we consider the full group of homeomorphisms of the Cantor set as well as Thompson's group $V$. We prove that both of these groups are boundedly…

Group Theory · Mathematics 2022-10-04 Konstantin Andritsch
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