Non-Uniqueness Phase in Hyperbolic Marked Random Connection Models using the Spherical Transform
Matthew Dickson
TL;DR
This work proves the existence of a non-uniqueness phase for infinite clusters in marked random connection models on hyperbolic space ${\mathbb{H}^d}$ (extended by marks in $\mathcal{E}$) in a high volume-scaling regime. It introduces an approach based on the spherical transform to diagonalize key operators and bound the $L^2\to L^2$ norms of the adjacency and two-point operators, while controlling the triangle diagram to access mean-field critical exponents. The authors establish that the susceptibility and percolation thresholds satisfy $\lambda_T(L) \le \lambda_c(L) \le \lambda_u(L)$ and, under favorable scaling (notably volume-linear), show $\lambda_c(L) < \lambda_u(L)$ for large $L$, thus a non-uniqueness regime. They further derive mean-field critical exponents in suitable regimes and apply the results to scaled Boolean disc models and weight-dependent hyperbolic RCMs, including non-perturbative cases with graphs that are not locally finite. The methodology hinges on a geometric-analytic blend: operator bounds, spherical-transform diagonalization, and hyperbolic geometry, enabling sharp control even in non-locally-finite settings and extending known non-uniqueness phenomena beyond amenable Euclidean settings.
Abstract
A non-uniqueness phase for infinite clusters is proven for a class of marked random connection models on the $d$-dimensional hyperbolic space, ${\mathbb{H}^d}$, in a high volume-scaling regime. The approach taken in this paper utilizes the spherical transform on ${\mathbb{H}^d}$ to diagonalize convolution by the adjacency function and the two-point function and bound their $L^2\to L^2$ operator norms. Under some circumstances, this spherical transform approach also provides bounds on the triangle diagram that allows for a derivation of certain mean-field critical exponents. In particular, the results are applied to some Boolean and weight-dependent hyperbolic random connection models. While most of the paper is concerned with the high volume-scaling regime, the existence of the non-uniqueness phase is also proven without this scaling for some random connection models whose resulting graphs are almost surely not locally finite.
