Renormalization group study of Bose-Einstein condensation

Due to the observation of Bose-Einstein condensation in dilute atomic Rb-87, Li-7, and Na-23 vapors last year, there is currently a great interest in the degenerate dilute Dose gas. Existing theoretical approaches using basically non-interacting Bogoliubov quasi-particles do not predict the deviation from the ideal gas critical temperature claimed to be observed in the experiments. Improving the theoretical analysis by including interactions between the Bogoliubov quasi-particles is however not trivial in the degenerate regime due to infrared divergencies showing up in regular perturbation theory. Motivated by these aspects we present a renormalization group study of the weakly-interacting homogeneous Bose gas.