Wave turbulence in Bose–Einstein condensates

The kinetics of nonequilibrium Bose–Einstein condensates (BEC) are considered within the framework of the Gross–Pitaevskii (GP) equation. A systematic derivation is given for weak small-scale perturbations of a steady confined condensate state. This approach combines a wavepacket WKB description with the weak turbulence theory. The WKB theory derived in this paper describes the effect of the condensate on the short-wave excitations which appears to be different from a simple renormalization of the confining potential suggested in previous literature.