The soliton-theory tag is for any questions regarding exactly solvable nonlinear PDE's such as Korteweg-De Vries, nonlinear Schrödinger, Sine-Gordon, etc. Other important related concepts are the Lax Pair, the AKNS Scheme, the Inverse Scattering Transform, the Gel'fand-Levitan-Marchenko equation, and the scattering data.
The soliton-theory tag is for any questions regarding exactly solvable nonlinear PDE's such as Korteweg-De Vries, nonlinear Schrödinger, Sine-Gordon, etc. Other important related concepts are the Lax Pair, the AKNS Scheme, the Inverse Scattering Transform, the Gel'fand-Levitan-Marchenko equation, and the scattering data.
See the Inverse Scattering Transform wiki for more information and references.