Asymptotic theory of not completely integrable soliton equations

Abstract

We develop the theory of transformation of intensive initial nonlinear wave pulses to trains of solitons emerging at asymptotically large time of evolution. Our approach is based on the theory of dispersive shock waves in which the number of nonlinear oscillations in the shock becomes the number of solitons at the asymptotic state. We show that this number of oscillations, which is proportional to the classical action of particles associated with the small-amplitude edges of shocks, is preserved by the dispersionless flow. Then the Poincaré-Cartan integral invariant is also constant and therefore it reduces to the quantization rule similar to the Bohr-Sommerfeld quantization rule for linear spectral problem associated with completely integrable equations. This rule yields a set of `eigenvalues' which are related with the asymptotic solitons' velocities and other their characteristics. Our analytical results agree very well with the results of numerical solutions of the generalized nonlinear Schrödinger equation.

12 pages

References in corpus (5)

• The theory of optical dispersive shock waves in photorefractive media
• On Whitham theory for perturbed integrable equations
• Propagation of wave packets along large-scale background waves
• Propagation of wave packets along intensive simple waves
• Number of solitons produced from a large initial pulse in the generalized NLS dispersive hydrodynamics theory

Cited by in corpus (3)

• Propagation of generalized Korteweg-de Vries solitons along large-scale waves
• Quasiclassical integrability condition in AKNS scheme
• Propagation of dark solitons of DNLS equation along a large-scale background