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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.

First passage percolation, local uniqueness for interlacements and capacity of random walk

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 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 and and a typical length scale 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 , , 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.
Paper Structure (18 sections, 24 theorems, 232 equations, 2 figures)

This paper contains 18 sections, 24 theorems, 232 equations, 2 figures.

Key Result

Theorem 1.1

Fix some $\eta\in{(0,1)}$. There exist constants $0<c, C<\infty$, depending on $\eta$, such that for all $N\in{\mathbb{N}}$ and $u\in{(0,1/2]}$, if $G=\mathbb{Z}^3$ and $uN\geq C$ whereas if $G=\mathbb{Z}^4$ and $\sqrt{u}N\geq C\log(1/u)$

Figures (2)

  • Figure 1: Illustration of the proper embedding generated by a path $\gamma$ from $C_x^{l_k}$ to $\widetilde{C}_x^{L_k}$ (in red). Normal lines represent $C_{\cdot}^{l_n}$, dashed lines $\widetilde{C}_{\cdot}^{L_n}$, and dotted lines ${C}_{\cdot}^{L_n}$, with $n=k$ in black, $n=k-1$ in green, and $n=k-2$ in blue.
  • Figure 2: The strategy to ensure that the local uniqueness event does not occur: a) There is exactly one trajectory hitting $B(x'_{P'},N'/P)$, and this trajectory visits $B(z,N'/P)$ while staying confined in the tube $\widetilde{\mathcal{L}}^{P,N'}_z$. b) There are trajectories hitting $B(x'_M,N'/P)$, the first such trajectory visits $B(x,N'/P)$ while staying confined in the tube $\widetilde{\mathcal{L}}^{P,N'}_x$, whereas all the other such (dashed) trajectories never visit $B(x,\xi N)$. c) Any other (dashed) trajectory never visits $\widetilde{\mathcal{L}}_z^{P,N'}$.

Theorems & Definitions (60)

  • Theorem 1.1
  • Theorem 1.2
  • Theorem 1.3
  • Lemma 2.1
  • proof
  • Remark 2.2
  • Theorem 3.1
  • Proposition 3.2
  • Proposition 3.3
  • Proposition 3.4
  • ...and 50 more