General approach to spatiotemporal modulational instability processes
نویسندگان
چکیده
منابع مشابه
Wave envelopes with second-order spatiotemporal dispersion: II. Modulational instabilities and dark Kerr solitons
A simple scalar model for describing spatiotemporal dispersion of pulses, beyond the classic “slowly-varying envelopes + Galilean boost” approach, is studied. The governing equation has a cubic nonlinearity and we focus here mainly on contexts with normal group-velocity dispersion. A complete analysis of continuous waves is reported, including their dispersion relations and modulational instabi...
متن کاملModulational instability of dust ion acoustic waves in astrophysical dusty plasmas with non thermal electrons
Propagation of dust ion acoustic waves in plasmas composed of nonthermal distributed electrons and stationary dust particles is investigated. Nonlinear Schrdinger equation is derived to describe small amplitude waves, using the reduction perturbation technique. Modulation instability of dust ion acoustic waves is analysed for this system. Parametric investigation indicates that growth rate of...
متن کاملConvective and absolute Eckhaus instability leading to modulated waves in a finite box.
We report an experimental study of the secondary modulational instability of a one-dimensional nonlinear traveling wave in a long bounded channel. Two qualitatively different instability regimes involving fronts of spatiotemporal defects are linked to the convective and absolute nature of the instability. Both transitions appear to be subcritical. The spatiotemporal defects control the global m...
متن کاملVariational approach to the modulational instability.
We study the modulational stability of the nonlinear Schrödinger equation using a time-dependent variational approach. Within this framework, we derive ordinary differential equations (ODE's) for the time evolution of the amplitude and phase of modulational perturbations. Analyzing the ensuing ODE's, we rederive the classical modulational instability criterion. The case (relevant to application...
متن کاملModulational Instability and Stationary Waves for the Coupled Generalized Schrödinger-Boussinesq System
The coupled generalized Schrödinger-Boussinesq (SB) system, which can describe a highfrequency mode coupled to a low-frequency wave in dispersive media is investigated. First, we study the modulational instability (MI) of the SB system. As a result, the general dispersion relation between the frequency and the wave number of the modulating perturbations is derived, and thus a number of possible...
متن کامل