English

Conformal dimension of hyperbolic groups that split over elementary subgroups

Metric Geometry 2022-08-23 v2 Classical Analysis and ODEs Group Theory

Abstract

We study the (Ahlfors regular) conformal dimension of the boundary at infinity of Gromov hyperbolic groups which split over elementary subgroups. If such a group is not virtually free, we show that the conformal dimension is equal to the maximal value of the conformal dimension of the vertex groups, or 1, whichever is greater, and we characterise when the conformal dimension is attained. As a consequence, we are able to characterise which Gromov hyperbolic groups (without 22-torsion) have conformal dimension 1, answering a question of Bonk and Kleiner.

Keywords

Cite

@article{arxiv.2007.09030,
  title  = {Conformal dimension of hyperbolic groups that split over elementary subgroups},
  author = {Matias Carrasco and John M. Mackay},
  journal= {arXiv preprint arXiv:2007.09030},
  year   = {2022}
}

Comments

v1: 47 pages, 6 figures; v2: 48 pages, 6 figures, minor changes to introduction

R2 v1 2026-06-23T17:11:57.010Z