Nearly solitons for a perturbed higher-order nonlinear Schr ̈dinger equation

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

Keywords:

higher-order Schrödinger equation , IST , soliton perturbation theory , squared eigenfunctions