English

Random infinite ideal angled graphs and ideal hyperbolic polyhedra

Probability 2026-01-22 v1 Combinatorics Complex Variables Differential Geometry Geometric Topology

Abstract

This article aims to develop the uniformization and boundary theory of random infinite ideal hyperbolic polyhedra (abbr. IHP) and their dual 1-skeleton, i.e., ideal angled graphs (abbr. IAG) from multiple perspectives, including combinatorics, geometry, analysis and random walks. For unimodular random IAG, we establish an ICP analog of the dichotomy theorem of Angel-Hutchcroft-Nachmias-Ray [4,5]. Specifically, the character T(ρ):=eρΘeT(\rho):=\sum_{e\ni\rho}\Theta_e of an IAG, introduced in [40], determines its ICP type: the graph is a.s. ICP-parabolic if and only if E[T(ρ)]=2π\mathbb{E}[T(\rho)]=2\pi. In the ICP-hyperbolic case, the simple random walk converges a.s. to D\partial\mathbb{D} with positive hyperbolic speed. Moreover, the geometric, Poisson, Martin, and Gromov boundaries coincide, extending the boundary theory of Angel-Barlow-Gurevich-Nachmias [3] and Hutchcroft-Peres [37] beyond triangulations to cellular decompositions. As a corollary of the aforementioned IHP/IAG duality, we obtain the systematic characterizations of the random IHP. To develop our theory, we strengthen and refine the Ring Lemma of Ge-Yu-Zhou [27] for ICP, which provides quantitative local control of the packing geometry. This key estimate makes it possible to extend the boundary theory beyond triangulations.

Keywords

Cite

@article{arxiv.2601.14909,
  title  = {Random infinite ideal angled graphs and ideal hyperbolic polyhedra},
  author = {Huabin Ge and Yangxiang Lu and Chuwen Wang and Tian Zhou},
  journal= {arXiv preprint arXiv:2601.14909},
  year   = {2026}
}
R2 v1 2026-07-01T09:13:57.515Z