Long-time dynamics of small solutions to 1$d$ cubic nonlinear Schr\"odinger equations with a trapping potential

Abstract

In this paper, we analyze the long-time dynamics of small solutions to the $1d$ cubic nonlinear Schr\"odinger equation (NLS) with a trapping potential. We show that every small solution will decompose into a small solitary wave and a radiation term which exhibits the modified scattering. In particular, this result implies the asymptotic stability of small solitary waves. Our analysis also establishes the long-time behavior of solutions to a perturbation of the integrable cubic NLS with the appearance of solitons.