Collective excitations in Bose-Einstein condensates in triaxially   anisotropic parabolic traps
  The wave equation of low-frequency density waves in Bose-Einstein condensates at vanishing temperature in arbitrarily anisotropic harmonic traps is separable in elliptic coordinates, provided the condensate can be treated in the Thomas-Fermi approximation. We present a complete solution of the mode functions, which are polynomials of finite order, and their eigenfrequencies which are characterized by three integer quantum numbers. 
Andr\'as Csord\'as (Research Group for Statistical Physics of the   Hungarian Academy of Sciences, Budapest, Hungary) and Ro...