One-ended spanning subforests and treeability of groups

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Conley, Clinton T., Gaboriau, Damien, Marks, Andrew S., Tucker-Drob, Robin D.
Formato: Preprint
Publicado: 2021
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866917352973533184
author Conley, Clinton T.
Gaboriau, Damien
Marks, Andrew S.
Tucker-Drob, Robin D.
author_facet Conley, Clinton T.
Gaboriau, Damien
Marks, Andrew S.
Tucker-Drob, Robin D.
contents We show that several new classes of groups are measure strongly treeable. In particular, finitely generated groups admitting planar Cayley graphs, elementarily free groups, and the group of isometries of the hyperbolic plane and all its closed subgroups. This provides the first examples of one-ended nonamenable groups which are measure strongly treeable. In higher dimensions, we also prove a dichotomy that the fundamental group of a closed aspherical 3-manifold is either amenable or has strong ergodic dimension 2. Our main technical tool is a method for finding measurable treeings of Borel planar graphs by constructing one-ended spanning subforests in their planar dual. Our techniques for constructing one-ended spanning subforests also give a complete classification of the locally finite pmp graphs which admit Borel a.e. one-ended spanning subforests.
format Preprint
id arxiv_https___arxiv_org_abs_2104_07431
institution arXiv
publishDate 2021
record_format arxiv
spellingShingle One-ended spanning subforests and treeability of groups
Conley, Clinton T.
Gaboriau, Damien
Marks, Andrew S.
Tucker-Drob, Robin D.
Group Theory
Dynamical Systems
Logic
Operator Algebras
Probability
37A20 (03E15, 22F10, 05C10)
We show that several new classes of groups are measure strongly treeable. In particular, finitely generated groups admitting planar Cayley graphs, elementarily free groups, and the group of isometries of the hyperbolic plane and all its closed subgroups. This provides the first examples of one-ended nonamenable groups which are measure strongly treeable. In higher dimensions, we also prove a dichotomy that the fundamental group of a closed aspherical 3-manifold is either amenable or has strong ergodic dimension 2. Our main technical tool is a method for finding measurable treeings of Borel planar graphs by constructing one-ended spanning subforests in their planar dual. Our techniques for constructing one-ended spanning subforests also give a complete classification of the locally finite pmp graphs which admit Borel a.e. one-ended spanning subforests.
title One-ended spanning subforests and treeability of groups
topic Group Theory
Dynamical Systems
Logic
Operator Algebras
Probability
37A20 (03E15, 22F10, 05C10)
url https://arxiv.org/abs/2104.07431