Collapse times of dipolar Bose-Einstein condensates

We investigate the time taken for global collapse by a dipolar Bose-Einstein condensate. Two semianalytical approaches and exact numerical integration of the mean-field dynamics are considered. The semianalytical approaches are based on a Gaussian ansatz and a Thomas-Fermi solution for the shape of the condensate. The regimes of validity for these two approaches are determined, and their predictions for the collapse time revealed and compared …