Bose-Einstein Condensation in Anisotropic Harmonic Traps
  We study the thermodynamic behaviour of an ideal gas of bosons trapped in a three-dimensional anisotropic harmonic oscillator potential. The condensate fraction as well as the specific heat is calculated using the Euler-Maclaurin approximation. For a finite number of particles there is no phase transition, but there is a well defined temperature at which the condensation starts. We also consider condensation in lower dimensions, and for one-dimensional systems we discuss the dependence of the condensate fraction and heat capacity on the ensemble used. 
T. Haugset, H. Haugerud and J. O. Andersen