Existence of multiple solutions to a class of nonlinear Schr\"{o}dinger   system with external sources terms
  We study a class of nonlinear schr\"{o}dinger system with external sources terms as perturbations in order to obtain existence of multiple solutions, this system arises from Bose-Einstein condensates etc..As these external sources terms are positive functions and small in some sense, we use Nehari manifold to get the existence of a positive ground state solution and a positive bound state solution. 
Zexin Qi and Zhitao Zhang
math.AP