PHONON-ASSISTED BOLTZMANN KINETICS OF A BOSE-GAS - GENERIC SOLUTION FOR T-LESS-THAN-OR-EQUAL-TO-T-C

The relaxation kinetics of an ideal Bose gas coupled to a phonon bath at temperatures below or equal to the critical temperature T-c is give n within a unique scenario. During the first transient stage, which la sts a few characteristic scattering times, the initial distribution di sappears. The following nonexponential relaxation towards a quantum de generate equilibrium state with a Bose-Einstein condensate is a slow a diabatic process. For this second kinetic stage we find an analytic ge neric solution of the Boltzmann equation. The generic solution is inde pendent of the initial distribution and completely defined by the rati o T-c/T-b of the critical and bath temperatures.