ASYMPTOTIC BEHAVIOUR OF THE ONE-DIMENSIONAL “ROCK–PAPER–SCISSORS” CYCLIC CELLULAR AUTOMATON

The one-dimensional three-state cyclic cellular automaton is a simple spatial model with three states in a cyclic “rock–paper–scissors” prey–predator relationship. Starting from a random configuration, similar states gather in increasingly large clusters; asymptotically, any finite region is filled with a uniform state that is, after some time, driven out by its predator, each state taking its turn in dominating the region (heteroclinic cycles). We consider the situation where each site in the initial configuration is chosen independently at random with a different probability for each state. We prove that the asymptotic probability that a state dominates a finite region corresponds to the initial probability of its prey. The proof methods are based on discrete probability tools, mainly particle systems and random walks.