Random majority percolation


We shall consider the discrete time synchronous random majority-vote cellular automata on the n by n torus, in which every vertex is in one of two states and, at each time step t, every vertex goes into the state the majority of its neighbors had at time t - 1 with a small chance p of error independently of all other events. We shall show that, if n is fixed and p is sufficiently small, then the process spends almost half of its time in each of two configurations. Further more, we show that the expected time for it to reach one of these configurations from the other is Θ(1/pn+1) despite the actual time spent in transit being O(1/p3). Unusually, it appears difficult to obtain any results for this regime by simulation. © 2009 Wiley Periodicals, Inc.

Publication Title

Random Structures and Algorithms