par Kozyreff, Gregory 
Référence Rencontre du Non-Linéaire RNL 2024 (Paris)
Publication Non publié, 2024-03-18
Référence Rencontre du Non-Linéaire RNL 2024 (Paris)
Publication Non publié, 2024-03-18
Communication à un colloque
| Résumé : | The group velocity is an important unifying concept in wave phenomena. It yields the speed of wave packets and generally differs from that of the phase velocity of the underlying oscillations. Moreover, its validity carries over to the realm of weakly nonlinear wave packet through the universal nonlinear Schrodinger equation (NLS). However, this communication reports that in this general frame, the group velocity, and hence the NLS, cease to describe the dynamics of wave packet when the group and phase velocities are very close to one other. This is demonstrated using exponential asymptotics and Stokes phenomenon. The result is a surprisingly simple and familiar equation of motion for the wave packet. |
