Nature of phase transitions in a probabilistic cellular automaton with twoabsorbing states - art. no. 046116

We present a probabilistic cellular automaton with two absorbing states, wh ich can be considered a natural extension of the Domany-Kinzel model. Despi te its simplicity, it shows a very rich phase diagram, with two second-orde r and one first-order transition lines that meet at a bicritical point. We study the phase transitions and the critical behavior of the model using me an field approximations, direct numerical simulations and field theory. The second-order critical curves and the kink critical dynamics are found to b e in the directed percolation and parity conservation universality classes, respectively. The first-order phase transition is put in evidence by exami ning the hysteresis cycle. We also study the "chaotic" phase, in which two replicas evolving with the same noise diverge, using mean held and numerica l techniques. Finally, we show how the shape of the potential of the held-t heoretic formulation of the problem can be obtained by direct numerical sim ulations.