Stochastic asynchronism may trigger phase transitions in cellular automata
Résumé
Cellular automata are discrete dynamical systems that are widely used to model natural systems. Classically they are run with perfect synchrony ; i.e., the local rule is applied to each cell at each time step. A possible modification of the updating scheme consists in applying the rule with a fixed probability, call the synchrony rate. It has been shown in a previous work that varying the synchrony rate continuously could produce a discontinuity in the behaviour of the CA. This works aims at investigating the nature of this change of behaviour using intensive numerical simulations. We apply a two-step protocol to show that the phenomenon is a phase transition whose critical exponents are in good agreement with the predicted values of directed percolation.