a modified f-expansion method to find the exact traveling wave solutions of  two-component nonlinear partial differential equations (nlpdes) is discussed. we use this method to construct many new solutions to the nonlinear whitham-broer-kaup system (1+1)-dimensional. the solutions obtained include jacobi elliptic periodic wave solutions which exactly degenerate to the soliton solutions, triangu...

There has been much experimental and theoretical interest in blowout regime of plasma wakefield acceleration (PWFA), which features ultra-high accelerating fields, linear transverse focusing forces, and nonlinear plasma motion. Using an exact analysis, we examine here a fundamental limit of nonlinear PWFA excitation, by an infinitesimally short, relativistic electron beam. The beam energy loss ...

We predict the existence of new nonlinear electromagnetic wave modes in pair plasmas. The plasma may be either non-magnetized or immersed in an external magnetic field. The existence of these modes depends on the interaction of an intense circularly polarized electromagnetic wave with a plasma, where the nonlinear quantum vacuum effects are taken into account. This gives rise to new couplings b...

Kinetic and tluid treatments of nonlinear wave interactions (wave mixing and electromagnetic wave scatrering) in plasmas are considered and the difference between the two approaches is discussed. Solving the kinetic equation by the method of moments makes it possible to substantiate the validity and find the applicability range of the fluid approach to the study of nonlinear plasma processes. I...

The nonlinear self-interaction of an electrostatic surface wave on a semibounded quantum plasma with relativistic degeneracy is investigated by using quantum hydrodynamic (QHD) model and the Poisson’s equation with appropriate boundary conditions. It is shown that a part of the second harmonic generated through self-interaction does not have a true surface wave character but propagates obliquel...

Laser evolution and plasma wave excitation by a relativistically intense short-pulse laser in underdense plasma are investigated in the broad pulse limit, including the effects of pulse steepening, frequency redshifting, and energy depletion. The nonlinear plasma wave phase velocity is shown to be significantly lower than the laser group velocity and further decreases as the pulse propagates ow...

A robust energy transfer mechanism is found in nonlinear wave systems, which favors transfers toward modes interacting via triads with nonzero frequency mismatch, applicable in meteorology, nonlinear optics and plasma wave turbulence. We emphasize the concepts of truly dynamical degrees of freedom and triad precession. Transfer efficiency is maximal when the triads' precession frequencies reson...

Three–wave nonlinear resonant interaction (TWRI) is typically encountered in the description of any conservative nonlinear medium where the nonlinear dynamics can be considered as a perturbation of the linear wave solution, the lowest–order nonlinearity is quadratic in the field amplitudes, the three–wave resonance can be satisfied [1]. Indeed TWRI is the lowest–order nonlinear effect for a sys...

It is shown that an undesirable curvature of the wave front of a two-dimensional nonlinear wake wave, excited in uniform plasma by a relativistic charged bunch or laser pulse, may be compensated by radial change of the equilibrium plasma density.