Thermal nucleation of kink-antikink pairs.

We numerically study the thermal nucleaton 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 {ital 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.