FRONT FORM AND VELOCITY IN A ONE-DIMENSIONAL AUTOCATALYTIC A-]2A REACTION(B)

We consider the general irreversible A+B-->2A autocatalytic reaction i n one dimension, for which the corresponding diffusion constants D-A a nd D-B may differ. Contrary to mean-field-type predictions, the Monte Carlo simulations show that, as long as D-A>0, only a unique, stable f ront propagates with constant velocity. When D-A=0 the behavior change s drastically: both the front's position and its characteristic width grow with t(1/2). These findings are adequately described within a Smo luchowski-type approach.