Asymptotics for the percolation threshold of finitary random interlacements in four and higher dimensions
Yijie Bi, Zhenhao Cai, Xinyi Li, Balázs Ráth, Yuan Zhang
TL;DR
This work determines sharp asymptotics for the percolation threshold of finitary random interlacements in dimensions $d\ge 4$ for general length distributions. The authors show that near-critical FRI behavior is well-approximated by a Galton–Watson process whose mean offspring equals the capacity of a random walk killed at the sampled length, yielding a universal limit formula $\lim_{n\to\infty} u_*(\rho_n)\cdot\frac{\mu_2(\rho_n)}{\mu_1(\rho_n)(1+\log\mu_1(\rho_n)\mathbbm{1}_{d=4})}}\varepsilon_d = 1$, with a logarithmic correction in $d=4$. The analysis combines layer-by-layer exploration, truncation of trajectories, coarse-graining into boxes, seeds, and a comparison to finitely dependent percolation via Liggett–Schonmann–Stacey domination. The results extend known asymptotics for geometric lengths and finite-range models to general length distributions, clarifying how long-range dependencies shape the percolation threshold in high dimensions. This provides a precise, robust description of phase transitions in FRI and informs related percolation models with long-range interactions.
Abstract
We establish sharp asymptotic bounds for the critical intensity of the Finitary Random Interlacements (FRI) model in four and higher dimensions with general trajectory length distributions. Our proof reveals that the construction of near-critical FRI clusters in four and higher dimensions is essentially analogous to a Galton-Watson process, whose expected number of offspring corresponds to the capacity of a random walk killed at the given length.
