Renormalization group of Bose-Einstein condensation

Abstract

Due to the observation of Bose-Einstein condensation in dilute atomic 87Rb, 7Li and 23Na vapors last years, there is currently a great interest in the degenerate dilute Bose 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 experiment. Improving the theoretical analysis by including interactions betwen the Bogoliubov quasi-particles is however not trivial in the degenerate regime due to infrared divergencies showing up in regular peturbation theory. Motivated by these aspects we present a renormalization group study of the weakly-interacting homogeneous Bose gas.