NEARLY SINGLE-SOLITON SOLUTION FOR A PERTURBED A HIGHER-ORDER NONLINEAR SCHRODINGER EQUATION

In the present paper we develop the soliton perturbation theory to nd nearly soliton solutions for a perturbed higher-order nonlinear Schr odinger (PHNLS) equation. An integral expression for the rst-order correction to the wave is found and to avoid the secular terms, the dynamical systems for the soliton parameters are found.