First passage percolation, local uniqueness for interlacements and capacity of random walk
Alexis Prévost
TL;DR
The paper addresses first passage percolation for the random interlacements model on transient graphs with polynomial volume growth and Green-function decay, establishing an asymptotically sharp lower bound for the probability that the FPP distance is sublinear and revealing near-critical behavior in the low-intensity regime. It develops a robust FPP framework on general graphs via coarse-graining, decoupling of interlacement excursions, soft local times, and entropy controls, culminating in a main FPP theorem that yields explicit large-deviation rates depending on the decay exponent $\nu$ of the Green function. These FPP bounds are then translated into sharp near-critical results for local uniqueness of random interlacements and capacity bounds for random walks in balls, with concrete dimension-specific refinements in $d=3$ and $d=4$ and a typical length scale $u^{-1/(d-2)}$ in the low-intensity regime. Overall, the work broadens the scope of FPP-type techniques from lattices to a versatile class of graphs, improving understanding of percolation, capacity, and geometric structure of interlacement-driven processes in subcritical and near-critical regimes.
Abstract
The study of first passage percolation (FPP) for the random interlacements model has been initiated in arXiv:2112.12096, where it is shown that on $\mathbb{Z}^d$, $d\geq 3$, the FPP distance is comparable to the graph distance with high probability. In this article, we give an asymptotically sharp lower bound on this last probability, which additionally holds on a large class of transient graphs with polynomial volume growth and polynomial decay of the Green function. When considering the interlacement set in the low-intensity regime, the previous bound is in fact valid throughout the near-critical phase. In low dimension, we also present two applications of this FPP result: sharp large deviation bounds on local uniqueness of random interlacements, and on the capacity of a random walk in a ball.
