Liquid-Gas phase transition in Bose-Einstein Condensates

We study the effects of a repulsive three-body interaction on a system of trapped ultra-cold atoms in a Bose-Einstein condensed state. The corresponding $s-$wave non-linear Schr"{o}dinger equation is solved numerically and also by a variational approach. A first-order liquid-gas phase transition is observed for the condensed state up to a critical strength of the effective three-body force.