English

Approximating hyperbolic lattices by cubulations

Group Theory 2024-06-14 v1 Geometric Topology

Abstract

We show that an isometric action of a torsion-free uniform lattice Γ\Gamma on hyperbolic space Hn\mathbb{H}^n can be metrically approximated by geometric actions of Γ\Gamma on CAT(0)\mathrm{CAT}(0) cube complexes, provided that either nn is at most three, or the lattice is arithmetic of simplest type. This solves a conjecture of Futer and Wise. Our main tool is the study of a space of co-geodesic currents, consisting of invariant Radon measures supported on codimension-1 hyperspheres in the Gromov boundary of Hn\mathbb{H}^n. By pairing co-geodesic currents and geodesic currents via an intersection number, we show that asymptotic convergence of geometric actions can be deduced from the convergence of their dual co-geodesic currents. For surface groups, our methods also imply approximation by cubulations for actions induced by non-positively curved Riemannian surfaces with singularities, Hitchin and maximal representations, and quasiFuchsian representations.

Keywords

Cite

@article{arxiv.2404.01511,
  title  = {Approximating hyperbolic lattices by cubulations},
  author = {Nic Brody and Eduardo Reyes},
  journal= {arXiv preprint arXiv:2404.01511},
  year   = {2024}
}

Comments

46 pages, 1 figure

R2 v1 2026-06-28T15:40:53.092Z