Long-time asymptotic for the derivative nonlinear Schrödinger equation with step-like initial value

Jian Xu, Engui Fan

We consider the Cauchy problem for the Gerdjikov-Ivanov(GI) type of the derivative nonlinear Schrödinger (DNLS) equation: $$i{q}_t+q_{xx}-i{q}^2{\bar{q}}_x+\frac{1}{2}|q{|}^{4}q=0.$$ with…