Molecular Physics Reports 30- (2001), page: 46-57
FLUCTUATIONS OF IDEAL BOSE-EINSTEIN CONDENSATE
The textbook theory of Bose-Einstein condensation is based on the grand canonical ensemble. The fluctuations of the number of condensed atoms according to this ensemble are totally unrealistic. Moreover, in the recent experiments nearly perfect isolation of atoms in a trap calls for a microcanonical description of the condensate. We review a progress in this area. We stress the usefulness of the Maxwell Demon ensemble.