NUCLEATION OF WEAKLY DRIVEN KINKS

We study nucleation of kink-antikink pairs under weak nonequilibrium c onditions and in the strong friction limit. We introduce an effective critical nucleus of size s(0), which is small compared to the inverse kink density but large compared to a kink size. We evaluate independen tly the nucleation rate and the kink lifetime from a multidimensional Kramers theory and by studying kink-antikink annihilation processes. W e find a kink density which is independent of s(0) and of the driving force in this regime. The result is in accordance with the equilibrium kink density obtained from statistical mechanics.