Critical analysis of the Bogoliubov theory of superfluidity

The microscopic theory of superfluidity (J. Phys. (USSR) 11 (1947) 23; Izv. Akad. Nauk USSR 11 (1947) 77; Bull. Moscow State Univ. 7 (1947) 43) was proposed by Bogoliubov in 1947 to explain the Landau-type excitation spectrum of 4He. An analysis of the Bogoliubov theory has already been done in the recent review (Phys. Rep. 350 (2001) 291). Here we perform a new constructive critical analysis of this theory in order to come to a better model. For this we briefly review the existing theory and carefully point out the weak points to settle a new approach. This leads us to consider the superstable Bogoliubov model (J. Phys. A 25 (1992) 3473). Thus, this constructive analysis is the origin of an improvement of the previous theory for which we verify the physical arguments.