Modulational Instability of (1+1)-Dimensional Bose--Einstein Condensate with Three-Body Interatomic Interaction

The modulational instability of Bose--Einstein condensate with three-body interatomic interaction and external harmonic trapping potential is investigated. Both of our analytical and numerical results show that the external potential will either cause the excitation of modulationally unstable modes or restrain the modulationally unstable modes from growing.