Absence of percolation for infinite Poissonian systems of stopped paths

TL;DR

This paper proves that in a model of randomly growing paths from a Poisson point process in two-dimensional space, no infinite cluster forms, demonstrating the absence of percolation under mild conditions.

Contribution

It establishes the non-percolation result for a dynamic continuum percolation model with stopping paths, under broad assumptions including the loop condition.

Findings

No infinite clusters form in the model.

Finite clusters contain loops and occur with positive probability.

Long-range dependencies complicate traditional analysis methods.

Abstract

The state space of our model is the Euclidean space in dimension d = 2. Simultaneously, from all points of a homogeneous Poisson point process, we let grow independent and identically distributed random continuum paths. Each path stops growing at time t \> 0 if it hits the trace of the other curves realized up until time t. Such dynamic is well-defined as long as the distribution of paths has a finite second moment at each time t \> 0. Letting the time runs until infinity so that each path reaches its stopping curve, we study the connected property of the graph formed by all stopped curves. Our main result states the absence of percolation in this graph, meaning that each cluster consists of a finite number of curves. The assumptions on the distribution of paths are very mild, with the main one being the so-called 'loop assumption' which ensures that finite clusters (necessarily containing a loop) occur with positive probability. The main issue in this model comes from the long-range dependence arising from long sequences of causalities in the hitting/stopping procedure. Most methods based on block approaches fail to effectively address the question of percolation in this setting.