TY - JOUR A1 - Idziaszek, Zbigniew A1 - Gajda, M. A1 - Navez, Patrick A1 - Wilkens, Martin A1 - Rzazewski, Kazimierz T1 - Fluctuation of the Weakly Interacting Bose-Einstein Condensate N2 - We consider the role of weak interaction on the fluctuations of the number of condensed atoms within canonical and microanonical ensembles. Unlike the correspinding case of the ideal gas this is not a clean, well-defined problem of mathematical physics. Two related reasons are the following: there is no unique way of defining the condensate fraction of the interacting system and no exact energy levels of the interacting system are known. Y1 - 1999 UR - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/21546 ER -