English
Related papers

Related papers: Free coarse groups

200 papers

In this paper, we prove that if two `box spaces' of two residually finite groups are coarsely equivalent, then the two groups are `uniform measured equivalent' (UME). More generally, we prove that if there is a coarse embedding of one box…

Group Theory · Mathematics 2025-02-18 Kajal Das

For any left orderable group G, we recall from work of McCleary that isolated points in the space of left orderings correspond to basic elements in the free lattice ordered group over G. We then establish a new connection between the…

Group Theory · Mathematics 2009-09-03 Adam Clay

Let $\Gamma$ be a connected, triangle-free, planar graph with at least five vertices that has no separating vertices or edges. If the graph $\Gamma$ is $\mathcal{CFS}$, we prove that the right-angled Coxeter group $G_\Gamma$ is virtually a…

Group Theory · Mathematics 2019-10-30 Hoang Thanh Nguyen , Hung Cong Tran

Coarse geometry, and in particular coarse homotopy theory, has proven to be a powerful tool for approaching problems in geometric group theory and higher index theory. In this paper, we continue to develop theory in this area by proving a…

Geometric Topology · Mathematics 2025-03-03 Thomas Weighill

We are concerned with orderable groups and particularly those with orderings invariant not only under multiplication, but also under a given automorphism or family of automorphisms. Several applications to topology are given: we prove that…

Group Theory · Mathematics 2014-10-01 Dale Rolfsen , Bert Wiest

We prove that the full automorphism group and the outer automorphism group of the free group of countably infinite rank are coarsely bounded. That is, these groups admit no continuous actions on a metric space with unbounded orbits, and…

Group Theory · Mathematics 2023-04-11 George Domat , Hannah Hoganson , Sanghoon Kwak

We use a coarse version of the fundamental group first introduced by Barcelo, Kramer, Laubenbacher and Weaver to show that box spaces of finitely presented groups detect the normal subgroups used to construct the box space, up to…

Group Theory · Mathematics 2020-04-29 Thiebout Delabie , Ana Khukhro

We give a counterexample to a conjecture by Miasnikov, Ventura and Weil, stating that an extension of free groups is algebraic if and only if the corresponding morphism of their core graphs is onto, for every basis of the ambient group. In…

Group Theory · Mathematics 2021-01-05 Noam Kolodner

We introduce properties of metric spaces and, specifically, finitely generated groups with word metrics which we call coarse coherence and coarse regular coherence. They are geometric counterparts of the classical algebraic notion of…

K-Theory and Homology · Mathematics 2020-02-17 Boris Goldfarb , Jonathan L. Grossman

We study Bowditch's notion of a coarse median on a metric space and formally introduce the concept of a coarse median structure as an equivalence class of coarse medians up to closeness. We show that a group which possesses a uniformly…

Group Theory · Mathematics 2016-05-06 Rudolf Zeidler

This is the first of two papers which aim to understand quasi-isometries of a subclass of unimodular split solvable Lie groups. In the present paper, we show that locally (in a coarse sense), a quasi-isometry between two groups in this…

Metric Geometry · Mathematics 2008-02-20 Irine Peng

We establish two versions of a central theorem, the Family Colimit Theorem, for the coarse coherence property of metric spaces. This is a coarse geometric property and so is well-defined for finitely generated groups with word metrics. It…

K-Theory and Homology · Mathematics 2020-01-28 Boris Goldfarb , Jonathan L. Grossman

In this paper we compute the discrete fundamental groups of warped cones. As an immediate consequence, this allows us to show that there exist coarsely simply-connected expanders and superexpanders. This also provides a strong coarse…

Metric Geometry · Mathematics 2018-10-26 Federico Vigolo

We prove that affine Coxeter groups, even hyperbolic Coxeter groups and one-ended hyperbolic Coxeter groups are homogeneous in the sense of model theory. More generally, we prove that many (Gromov) hyperbolic groups generated by torsion…

Group Theory · Mathematics 2026-01-21 Simon André , Gianluca Paolini

We define a notion of free product for coarse spaces that generalizes the corresponding notion of a free product for groups. We show that free products preserve coarse properties such as coarse property C, finite coarse decomposition…

Geometric Topology · Mathematics 2020-06-26 Greg Bell , Austin Lawson

It is well-known that if $E$ is an elliptic curve over the finite field $\mathbb{F}_p$, then $E(\mathbb{F}_p)\simeq\mathbb{Z}/m\mathbb{Z}\times\mathbb{Z}/mk\mathbb{Z}$ for some positive integers $m, k$. Let $S(M,K)$ denote the set of pairs…

Number Theory · Mathematics 2017-06-12 Vorrapan Chandee , Chantal David , Dimitris Koukoulopoulos , Ethan Smith

In algebraic topology, the fundamental groupoid is a classical homotopy invariant which is defined using continuous maps from the closed interval to a topological space. In this paper, we construct a semi-coarse version of this invariant,…

Algebraic Topology · Mathematics 2025-03-06 Jonathan Treviño-Marroquín

To a coarse structure we associate a Grothendieck topology which is determined by coarse covers. A coarse map between coarse spaces gives rise to a morphism of Grothendieck topologies. This way we define sheaves and sheaf cohomology on…

Algebraic Geometry · Mathematics 2022-03-24 Elisa Hartmann

We begin the study the algebraic topology of semi-coarse spaces, which are generalizations of coarse spaces that enable one to endow non-trivial `coarse-like' structures to compact metric spaces, something which is impossible in coarse…

Algebraic Topology · Mathematics 2024-10-01 Antonio Rieser , Jonathan Treviño-Marroquín

A finitely generated group admits a decomposition, called its Grushko decomposition, into a free product of freely indecomposable groups. There is an algorithm to construct the Grushko decomposition of a finite graph of finite rank free…

Group Theory · Mathematics 2014-11-11 Guo-An Diao , Mark Feighn