Infinite volume ends of quotient graphs and homogeneous spaces

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autore principale: Wróbel, Konrad
Natura: Preprint
Pubblicazione: 2024
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866912609111900160
author Wróbel, Konrad
author_facet Wróbel, Konrad
contents We introduce the space of infinite volume ends of a locally compact second countable (lcsc) space that admits a Radon measure. In certain cases, this coincides with the classical space of ends. Consider a discrete subgroup $Γ$ of a unimodular lcsc group $G$ that is not coamenable. Assume that $G$ has property (T) and the associated homogeneous space $G/Γ$ is equipped with the Haar measure. We demonstrate that if $G$ is path connected, then $G/Γ$ has exactly one infinite volume end. In a related vein, if $G$ acts transitively on a locally finite connected graph $X$ with compact open vertex stabilizers and the action of the subgroup $Γ$ is free, we show that $X/Γ$ has exactly one end. We also obtain identical results for certain discrete subgroups $Γ$ of nonamenable product groups $G$. These results can be applied to understand ends of Schreier graphs and infinite volume ends of quotients of symmetric spaces of noncompact type. For instance, for symmetric spaces $X$ of noncompact type without real or complex hyperbolic factors, every infinite-covolume quotient $Γ\backslash X$ has exactly one end of infinite Riemannian volume.
format Preprint
id arxiv_https___arxiv_org_abs_2411_19776
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Infinite volume ends of quotient graphs and homogeneous spaces
Wróbel, Konrad
Group Theory
Dynamical Systems
Geometric Topology
20F65 (Primary) 20J06, 57T15, 32M15 (Secondary)
We introduce the space of infinite volume ends of a locally compact second countable (lcsc) space that admits a Radon measure. In certain cases, this coincides with the classical space of ends. Consider a discrete subgroup $Γ$ of a unimodular lcsc group $G$ that is not coamenable. Assume that $G$ has property (T) and the associated homogeneous space $G/Γ$ is equipped with the Haar measure. We demonstrate that if $G$ is path connected, then $G/Γ$ has exactly one infinite volume end. In a related vein, if $G$ acts transitively on a locally finite connected graph $X$ with compact open vertex stabilizers and the action of the subgroup $Γ$ is free, we show that $X/Γ$ has exactly one end. We also obtain identical results for certain discrete subgroups $Γ$ of nonamenable product groups $G$. These results can be applied to understand ends of Schreier graphs and infinite volume ends of quotients of symmetric spaces of noncompact type. For instance, for symmetric spaces $X$ of noncompact type without real or complex hyperbolic factors, every infinite-covolume quotient $Γ\backslash X$ has exactly one end of infinite Riemannian volume.
title Infinite volume ends of quotient graphs and homogeneous spaces
topic Group Theory
Dynamical Systems
Geometric Topology
20F65 (Primary) 20J06, 57T15, 32M15 (Secondary)
url https://arxiv.org/abs/2411.19776