par Fujita, Shigeji
Référence Physica, 27, 12, page (1161-1169)
Publication Publié, 1961-12
Article révisé par les pairs
Résumé : A contraction theorem for a product of boson operators averaged over the modified grand canonical ensemble (called as the x-ensemble by Lee and Yang) of free particles is established. The theorem enables one to use the quantum statistical diagram technique for the calculation of statistical mechanical quantities of the degenerate interacting bosons. The diagram technique is illustrated by calculating the grand partition function of hard-sphere bosons above and below the temperature of the Bose-Einstein condensation. © 1957.