Anchored expansion of Delaunay complexes in real hyperbolic space and stationary point processes

We give sufficient conditions for a discrete set of points in any dimensional real hyperbolic space to have positive anchored expansion. The first condition is a bounded mean density property, ensuring not too many points can accumulate in large regions. The second is a bounded mean vacancy condition, effectively ensuring there is not too much space left vacant by the points over large regions. These properties give as an easy corollary that stationary Poisson--Delaunay graphs have positive anchored expansion, as well as Delaunay graphs built from stationary determinantal point processes. We introduce a family of stationary determinantal point processes on any dimension of real hyperbolic space, the Berezin point processes, and we partially characterize them. We pose many questions related to this process and stationary determinantal point processes.