Collective excitations of degenerate Fermi gases in anisotropic parabolic traps

We investigate the hydrodynamic low-frequency oscillations of highly degenerate Fermi gases trapped in anisotropic harmonic potentials. Despite the lack of an obvious spatial symmetry the wave equation turns out to be separable in elliptical coordinates, similar to a corresponding result established earlier for Bose condensates. This result is used to give an analytical solution of the anisotropic wave equation for the hydrodynamic modes.