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Related papers: Hyperbolicity vs. Amenability for planar graphs

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We investigate the relationship between the metric boundary and the Gromov boundary of a hyperbolic metric space. We show that the Gromov boundary is a quotient topological space of the metric boundary, and that therefore a word-hyperbolic…

Metric Geometry · Mathematics 2007-05-23 Corran Webster , Adam Winchester

In this article we discuss relations between algebraic and dynamical properties of non-cyclic semigroups of rational maps.

Dynamical Systems · Mathematics 2021-11-08 Carlos Cabrera , Peter Makienko

In this paper we give a characterization of the Gromov hyperbolicity of trains (a large class of Denjoy domains which contains the flute surfaces) in terms of the behavior of a real function. This function describes somehow the distances…

Complex Variables · Mathematics 2008-06-03 Ana Portilla , Jose M. Rodriguez , Eva Touris

We compare a Gromov hyperbolic metric with the hyperbolic metric in the unit ball or in the upper half space, and prove sharp comparison inequalities between the Gromov hyperbolic metric and some hyperbolic type metrics. We also obtain…

Complex Variables · Mathematics 2020-06-09 Xiaoxue Xu , Gendi Wang , Xiaohui Zhang

In this paper, we introduce the concepts of short arc and length map in quasihyperbolic metric spaces, and obtain some geometric characterizations of Gromov hyperbolicity for quasihyperbolic metric spaces in terms of the properties of short…

Metric Geometry · Mathematics 2024-11-12 Hongjun Liu , Ling Xia , Shasha Yan

We present a careful approximation of the geodesics in trees of hyperbolic or relatively hyperbolic groups. As an application we prove a combination theorem for finite graphs of relatively hyperbolic groups, with both Farb's and Gromov's…

Group Theory · Mathematics 2008-03-24 F. Gautero

We give a complete characterization of the locally compact groups that are non-elementary Gromov-hyperbolic and amenable. They coincide with the class of mapping tori of discrete or continuous one-parameter groups of compacting…

Group Theory · Mathematics 2015-10-29 Pierre-Emmanuel Caprace , Yves de Cornulier , Nicolas Monod , Romain Tessera

We consider various equivalence relations on the set of homotopy classes of curves on a hyperbolic surface based on topological, algebraic, and geometric structures. The purpose of this work is to determine the relationship between these…

Geometric Topology · Mathematics 2007-05-23 Christopher J. Leininger

Hyperfiniteness or amenability of measurable equivalence relations and group actions has been studied for almost fifty years. Recently, unexpected applications of hyperfiniteness were found in computer science in the context of testability…

Functional Analysis · Mathematics 2012-05-31 Gabor Elek

This survey introduces to the hyperbolic unfolding correspondence that links the geometric analysis of minimal hypersurfaces with that of Gromov hyperbolic spaces. Problems caused from hypersurface singularities oftentimes become solvable…

Differential Geometry · Mathematics 2022-04-29 Joachim Lohkamp

In this paper, we introduce the concept of quasihyperbolically visible spaces. As a tool, we study the connection between the Gromov boundary and the metric boundary.

Metric Geometry · Mathematics 2026-04-15 Vasudevarao Allu , Abhishek Pandey

In this paper we consider aspects of geometric observability for hypergraphs, extending our earlier work from the uniform to the nonuniform case. Hypergraphs, a generalization of graphs, allow hyperedges to connect multiple nodes and…

Dynamical Systems · Mathematics 2024-04-12 Joshua Pickard , Cooper Stansbury , Amit Surana , Indika Rajapakse , Anthony Bloch

We study the automorphism groups of countable homogeneous directed graphs (and some additional homogeneous structures) from the point of view of topological dynamics. We determine precisely which of these automorphism groups are amenable…

Combinatorics · Mathematics 2017-12-29 Micheal Pawliuk , Miodrag Sokic

Scharlemann and Thompson define the width of a 3-manifold M as a notion of complexity based on the topology of M. Their original definition had the property that the adjacency relation on handles gave a linear order on handles, but here we…

Geometric Topology · Mathematics 2017-08-15 Diane Hoffoss , Joseph Maher

The purpose of this paper is to define some notions of movability for morphisms of inverse systems which extend the movability properties of inverse systems and which are compatible with the equivalence relations which define pro-morphisms…

Algebraic Topology · Mathematics 2016-06-09 P. S. Gevorgyan , I. Pop

We discuss relations between the amenability of a graph and spectral properties of a random walk driven by a dynamical system. In order to include graphs which are not locally compact, we introduce the concept of amenability of weighted…

Dynamical Systems · Mathematics 2024-04-15 Johannes Jaerisch , Elaine Rocha , Manuel Stadlbauer

Recent papers in the graph machine learning literature have introduced a number of approaches for hyperbolic representation learning. The asserted benefits are improved performance on a variety of graph tasks, node classification and link…

Machine Learning · Computer Science 2025-02-26 Isay Katsman , Anna Gilbert

Let $G=(V,E)$ be a connected graph with the usual (graph) distance metric $d:V \times V \to N \cup \{0 \}$. Introduced by Gromov, $G$ is $\delta$-hyperbolic if for every four vertices $u,v,x,y \in V$, the two largest values of the three…

Combinatorics · Mathematics 2014-06-12 Dieter Mitche , Pawel Pralat

In this paper we find some necessary and sufficient conditions for a Banach algebra to be amenable or weakly amenable, by applying the homomorphisms on Banach algebras.

Functional Analysis · Mathematics 2007-05-23 M. Eshaghi Gordji

Modularity is a quantity which has been introduced in the context of complex networks in order to quantify how close a network is to an ideal modular network in which the nodes form small interconnected communities that are joined together…

Probability · Mathematics 2021-04-05 Jordan Chellig , Nikolaos Fountoulakis , Fiona Skerman