  We present a unified account of damping of low-lying collective modes and of
relaxation of temperature anisotropies in a trapped Bose gas in the
collisionless regime. By means of variational techniques, we show that the
relaxation times for the two situations are closely related to the simplest
variational estimate of the viscous relaxation time. We derive rather precise
theoretical expressions for the characteristic relaxation times, and compare
our results with experiment.
