Stability of Multisolitons for the Derivative Nonlinear Schrödinger Equation

Abstract The nonlinear Schrödinger equation with derivative cubic nonlinearity admits a family of solitons, which are orbitally stable in the energy space. In this work, we prove the orbital stability of multisolitons configurations in the energy space, under suitable assumptions on the speeds and frequencies of the composing solitons. The main ingredients of the proof are modulation theory, energy coercivity, and monotonicity properties.