Dynamics of a Bose–Einstein condensate in an anharmonic trap

We present a theoretical model for describing the dynamics of Bose–Einstein condensates in anharmonic trapping potentials. To first approximation the centre-of-mass motion is separated from the internal condensate dynamics and the problem is reduced to the well known scaling solutions for the Thomas–Fermi radii. We discuss the validity of this approach and analyse the model for an anharmonic waveguide geometry which was recently realized in an experiment (Ott et al 2002 Preprint cond-mat/0212220).