Abstract
The main observation of this paper is that the modified Korteweg-de Vries equation has its natural origin in phase modulation of a basic state such as a periodic travelling wave, or more generally, a family of relative equilibria. Extension to 2 + 1 suggests that a modified Kadomtsev-Petviashvili (or a Konopelchenko-Dubrovsky) equation should emerge, but our result shows that there is an additional term which has gone heretofore unnoticed. Thus, through the novel application of phase modulation a new equation appears as the 2 + 1 extension to a previously known one. To demonstrate the theory it is applied to the cubic-quintic nonlinear Schrödinger (CQNLS) equation, showing that there are relevant parameter values where a modified KP equation bifurcates from periodic travelling wave solutions of the 2 + 1 CQNLS equation.
Original language | English |
---|---|
Pages (from-to) | 3794-3813 |
Number of pages | 20 |
Journal | Nonlinearity |
Volume | 31 |
Issue number | 8 |
DOIs | |
Publication status | Published - 9 Jul 2018 |
Externally published | Yes |
Keywords
- Lagrangian fields
- nonlinear waves
- phase dynamics