Comment on "Collective Excitations of a Bose-Einstein Condensate in a Magnetic Trap"

We calculate the damping rate of collective excitations for a nearly pure Bose-Einstein condensate regarding the recent experiments in MIT [M.-O. Mews et al, Phys. Rev. Lett. 77, 988 (1996)]. The decay time of collective excitations obtained in our theoretical calculations agrees well with their experimental result. We argue that the damping of collective excitations is due to thermal contributions rather than interactions between collective modes.