SIMPLE NONEQUILIBRIUM EXTENSION OF THE ISING-MODEL

We introduce a simple nonequilibrium version of the Ising model, exhib iting an order-disorder phase transition. It corresponds to the compet ition of two different kinetic processes: one of them ordering the sys tem and the other one disordering it (temperatures zero and infinity, respectively). Owing to the simplicity of the model, it is possible to define a pseudotemperature T characterizing the system. By using T we elucidate a striking point recently arisen in the literature, namely, how does the critical region of nonequilibrium systems compare to tha t of their equilibrium counterparts. Extensive numerical simulations a re presented, and the conclusion is made that the model belongs in the equilibrium Ising model universality class confirming a well known co njecture.