Bose gas in power-like spherically symmetric potential in arbitrary   spatial dimensionality
  Temperature of the Bose -- Einstein condensation and the temperature behavior of the chemical potential and other thermodynamical functions of the ideal Bose gas are found for the arbitrary power-like spherical-symmetric potential at an arbitrary space dimension. It is shown that the recently observed Bose -- Einstein condensation of photons in the cavity is the phase transition of the third kind. 
A. A. Kozhevnikov
cond-mat.stat-mech cond-mat.quant-gas