Slow relaxation phenomena induced by breathers in nonlinear lattices

We study relaxation properties of one dimensional nonlinear lattices which are initially thermalized and subsequently put intp contact with a cold bath simulated by absorbing boundary conditions. We observe a nonexponential lattice energy relaxation in contrast to the standard exponential relaxation law of the corresponding linear system. We connect the long-tail relaxation behavior with the presence of long-lived nonlinear localized modes. The mobility of the breathers is shown to play a substantial role in the lattice relaxation properties.