Topology and geometry of random 2-dimensional hypertrees

Type: 
Papers
Publisher: 

Discrete & Computational Geometry

Accepted: 
Jul 2021
Publication date: 
2022
Co-author: 
Matthew Kahle
Andrew Newman
Abstract: 
A hypertree, or $\mathbb{Q}$-acyclic complex, is a higher-dimensional analogue of a tree. We study random $2$-dimensional hypertrees according to the determinantal measure suggested by Lyons. We are especially interested in their topological and geometric properties. We show that with high probability, a random $2$-dimensional hypertree $T$ is aspherical, i.e.\ that it has a contractible universal cover. We also show that with high probability the fundamental group $\pi_1(T)$ is hyperbolic and has cohomological dimension $2$.