Particle density and transition temperature of weakly interacting quantum gases

An expression for single particle density of weakly interacting trapped quantum gases has been obtained for Fermi gas at all temperatures and for Bose gas above the transition temperature (Tc). This expression has been used to study the effect of interaction on density of harmonically trapped Bose gas. It is found that interaction has a large effect on the density at centre of the trap as observed experimentally. The same expression for density is also used to obtain the transition temperature of homogeneous Bose gas. Experimental results for Tc has been re-analysed on the basis of perturbative and non-perturbative theories. It is found that both the theories fit experimental data equally well in low-density regimes.