THERMAL NUCLEATION OF KINK-ANTIKINK PAIRS

We numerically study the thermal nucleation of kink-antikink pairs in (1 + 1)-dimensional classical field theory coupled to a heat bath. We study the dependence of the kink lifetime and number density on temperature and on the coupling to the heat bath (viscosity). We qualitatively confirm Kramers's prediction of the viscosity dependence, and find a slight reduction in the effective kink mass compared with its zero-temperature value. We find no suppression of kink production beyond the Boltzmann factor, and we confirm a recent prediction of the renormalization of the barrier at high viscosity.