Study of kink-antikink pair production at finite temperature by means of the Langevin equation

Abstract
Creation of kink-antikink pairs within the (1+1) dimensional real scalar field theory at finite temperature is considered as a result of the real-time evolution of a Hamiltonian system which interacts with a thermal bath. The relevant Langevin equation is solved numerically on the lattice, and both the density of kinks and the pair-creation time are obtained as functions of the temperature. We find that the effective kink mass is reduced at high temperatures. This observation may be important for the evaluation of the cosmological production of monopoles.