HYDRODYNAMIC MODES AND PULSE-PROPAGATION IN A CYLINDRICAL BOSE-GAS ABOVE THE BOSE-EINSTEIN TRANSITION

We study hydrodynamic oscillations of a cylindrical Bose gas above the Bose-Einstein transition temperature using the hydrodynamic equations derived by Griffin, Wu, and Stringari. This extends recent studies of a cylindrical Bose-condensed gas at T=0. Explicit normal mode solutio ns are obtained for non-propagating solutions. In the classical limit, the sound velocity is shown to be the same as a uniform classical gas . We use a variational formulation of the hydrodynamic equations to di scuss the propagating modes in the degenerate Bose-gas limit and show there is little difference from the classical results. We discuss the propagation of sound pulses above and below T-BEC [S1050-2947(98)02311 -7].