New Solitary Solutions of (2+1)-Dimensional Variable Coefficient Nonlinear Schrödinger Equation with an External Potential

By a series of transformations, the (2+1)-dimensional variable coefficient nonlinear Schrödinger equation can turn to the Klein-Gordon equation. Many new double travelling wave solutions of the Klein-Gordon equation are obtained. Thus, the new solitary solutions of the variable coefficient nonlinear Schröinger equation with an external potential can be found.