Bose-Einstein condensation of atoms with attractive interaction in a harmonic trap

It is well known that bosonic particles with attractive interaction in a un iform gas do not form a condensate. Here we investigate a dilute Bose gas a nd study stationary solutions of the Gross-Pitaevskii equation with attract ive interaction. We have also used a higher order stabilising term in the p resence of a harmonic confining potential. We show that there are three pos sible types of stationary solutions corresponding to stable, metastable and unstable phases. These results are discussed in relation to a Li-7 condens ate.