On a class of probabilistic cellular automata with size-$3$ neighbourhood and their applications in percolation games

Abstract

Different versions of percolation games on ${\mathbb{Z}}^2$, with parameters $p$ and $q$ that indicate, respectively, the probability with which a site in ${\mathbb{Z}}^2$ is labeled a trap and the probability with which it is labeled a target, are shown to have probability $0$ of culminating in draws when $p+q>0$. We show that, for fixed $p$ and $q$, the probability of draw in each of these games is $0$ if and only if a certain $1$-dimensional probabilistic cellular automaton (PCA) $F_{p,q}$ with a size-$3$ neighbourhood is ergodic. This allows us to conclude that $F_{p,q}$ is ergodic whenever $p+q>0$, thereby rigorously establishing ergodicity for a considerable class of PCAs.

23 pages, last 2 pages bibliography, 6 images