Microscopic Evolution of a Weakly Interacting Homogeneous Bose Gas

Abstract

We provide a detailed description of the nonequilibrium time evolution of an interacting homogeneous Bose-Einstein condensate. We use a nonperturbative in-medium quantum field theory approach as a microscopic model for the Bose gas. The real-time dynamics of the condensate is encoded in a set of self-consistent equations which corresponds to an infinite sum of ladder Feynman diagrams. The crucial role played by the interaction between fluctuations for the instability generation is thoroughly described.

arXiv comment7 pages, 1 figure (uses epsfig). To appear in Laser Physics (2001), Special Issue on Bose-Einstein Condensation of Trapped Atoms. A few misprints and errors have been corrected