Renormalization theory of the interacting Bose fluid

We derive an approximate closed form for the infinitesimal generator of the renormalization group for the interacting Bose fluid. The Bose-condensed phase is treated by the method of Bogoliubov, and a simple scaling law is found for the condensate density. It is shown that the quantum-mechanical features are irrelevant close to the λ line. This is demonstrated by calculating the critical behavior in 4-ε dimensions to order ε.