Decay rates in attractive Bose-Einstein condensates

Attractive Bose-Einstein condensates are investigated with numerical contin uation methods capturing stationary solutions of the Gross-Pitaevskii equat ion. The branches of stable (elliptic) and unstable (hyperbolic) solutions are found to meet at a critical particle number through a generic Hamiltoni an saddle node bifurcation. The condensate decay rates corresponding to mac roscopic quantum tunneling, two and three body inelastic collisions, and th ermally induced collapse are computed from the exact numerical solutions. T hese rates show experimentally significant differences with previously publ ished rates. Universal scaling laws stemming from the bifurcation are deriv ed.