The nonlinear Schrödinger equation and the Hamilton-Jacobi equation – physics.stackexchange.com

The nonlinear Schrödinger equation (NLSE) is PDE for a classical field $\psi$: {\displaystyle i\partial _{t}\psi =-{1 \over 2}\partial _{x}^{2}\psi +\kappa |\psi |^{2}\psi }.\tag1 The Hamilton–...