Nonlinear electrostatic solitary waves in electron–positron plasmas

2016 ◽  
Vol 82 (1) ◽  
Author(s):  
I. J. Lazarus ◽  
R. Bharuthram ◽  
S. Moolla ◽  
S. V. Singh ◽  
G. S. Lakhina
Keyword(s):  
Solitary Waves ◽  
Laboratory Experiments ◽  
Nonlinear Propagation ◽  
Plasma Parameters ◽  
Electron Positron ◽  
Electrons And Positrons ◽  
Fluid Theory ◽  
Temperature Electron ◽  
Propagation Of Waves ◽  
Two Temperature

The generation of nonlinear electrostatic solitary waves (ESWs) is explored in a magnetized four component two-temperature electron–positron plasma. Fluid theory is used to derive a set of nonlinear equations for the ESWs, which propagate obliquely to an external magnetic field. The electric field structures are examined for various plasma parameters and are shown to yield sinusoidal, sawtooth and bipolar waveforms. It is found that an increase in the densities of the electrons and positrons strengthen the nonlinearity while the periodicity and nonlinearity of the wave increases as the cool-to-hot temperature ratio increases. Our results could be useful in understanding nonlinear propagation of waves in astrophysical environments and related laboratory experiments.

Solitary waves in asymmetric electron–positron–ion plasmas

2015 ◽  
Vol 81 (5) ◽  
Author(s):  
Ding Lu ◽  
Zi-Liang Li ◽  
Bai-Song Xie
Keyword(s):  
Solitary Waves ◽  
Ion Concentration ◽  
Temperature Plasma ◽  
Long Wavelength ◽  
Coupled Equations ◽  
Electron Positron ◽  
Electrons And Positrons ◽  
Relativistic Temperature ◽  
Temperature Electron ◽  
Wavelength Approximation

By solving the coupled equations of the electromagnetic field and electrostatic potential, we investigate solitary waves in an asymmetric electron–positron plasma and/or electron–positron–ion plasmas with delicate features. It is found that the solutions of the coupled equations can capture multipeak structures of solitary waves in the case of cold plasma, which are left out by using the long-wavelength approximation. By considering the effect of ion motion with respect to non-relativistic and ultra-relativistic temperature plasmas, we find that the ions’ mobility can lead to larger-amplitude solitary waves; especially, this becomes more obvious for a high-temperature plasma. The effects of asymmetric temperature between electrons and positrons and the ion fraction on the solitary waves are also studied and presented. It is shown that the amplitudes of solitary waves decrease with positron temperature in asymmetric temperature electron–positron plasmas and decrease also with ion concentration.

Modified Korteweg–de Vries–Zakharov–Kuznetsov solitons in symmetric two-temperature electron–positron plasmas

2008 ◽  
Vol 74 (4) ◽  
pp. 519-529 ◽  
Author(s):  
I. J. LAZARUS ◽  
R. BHARUTHRAM ◽  
M. A. HELLBERG
Keyword(s):  
Particle Number ◽  
Perturbation Technique ◽  
Boltzmann Distribution ◽  
Plasma Parameters ◽  
Oblique Propagation ◽  
Electron Positron ◽  
Reductive Perturbation ◽  
De Vries ◽  
Temperature Electron ◽  
Two Temperature

AbstractSolitary waves are investigated in a magnetized electron–positron plasma consisting of equal hot and cool components of each species. The hot components have a Boltzmann distribution and the cool components are described by the fluid equations. A modified Korteweg–de Vries–Zakharov–Kuznetsov equation governing the oblique propagation of nonlinear electrostatic modes is derived using the reductive-perturbation technique. Soliton amplitudes are studied as a function of plasma parameters such as the particle number densities and the temperatures. Such results may be of relevance to the magnetosphere of pulsars.

Semiclassical relativistic fluid theory for electrostatic envelope modes in dense electron–positron–ion plasmas: Modulational instability and rogue waves

2013 ◽  
Vol 79 (6) ◽  
pp. 1089-1094 ◽  
Author(s):  
IOANNIS KOURAKIS ◽  
MICHAEL MC KERR ◽  
ATA UR-RAHMAN
Keyword(s):  
Fluid Model ◽  
Modulational Instability ◽  
Rogue Waves ◽  
Relativistic Electrons ◽  
Relativistic Fluid ◽  
Ion Plasma ◽  
Electron Positron ◽  
Electrons And Positrons ◽  
Perturbative Method ◽  
Fluid Theory

AbstractA fluid model is used to describe the propagation of envelope structures in an ion plasma under the influence of the action of weakly relativistic electrons and positrons. A multiscale perturbative method is used to derive a nonlinear Schrödinger equation for the envelope amplitude. Criteria for modulational instability, which occurs for small values of the carrier wavenumber (long carrier wavelengths), are derived. The occurrence of rogue waves is briefly discussed.

Nonlinear ion acoustic excitations in relativistic degenerate, astrophysical electron–positron–ion plasmas

2013 ◽  
Vol 79 (5) ◽  
pp. 817-823 ◽  
Author(s):  
ATA-UR RAHMAN ◽  
S. ALI ◽  
A. MUSHTAQ ◽  
A. QAMAR
Keyword(s):  
Perturbation Technique ◽  
Collisionless Plasma ◽  
Plasma Parameters ◽  
Linear Dispersion ◽  
Electron Positron ◽  
Electrons And Positrons ◽  
Ion Acoustic ◽  
Astrophysical Objects ◽  
Collective Interactions ◽  
Acoustic Excitations

AbstractThe dynamics and propagation of ion acoustic (IA) waves are considered in an unmagnetized collisionless plasma, whose constituents are the relativistically degenerate electrons and positrons as well as the inertial cold ions. At a first step, a linear dispersion relation for IA waves is derived and analysed numerically. For nonlinear analysis, the reductive perturbation technique is used to derive a Korteweg–deVries equation, which admits a localized wave solution in the presence of relativistic degenerate electrons and positrons. It is shown that only compressive IA solitary waves can propagate, whose amplitude, width and phase velocity are significantly modified due to the positron concentration. The latter also strongly influences all the relativistic plasma parameters. Our present analysis is aimed to understand collective interactions in dense astrophysical objects, e.g. white dwarfs, where the lighter species electrons and positrons are taken as relativistically degenerate.

Do nonlinear waves evolve in a universal manner in dusty and other plasma environments?

2014 ◽  
Vol 80 (6) ◽  
pp. 825-832 ◽  
Author(s):  
R. Bharuthram ◽  
S. V. Singh ◽  
S. K. Maharaj ◽  
S. Moolla ◽  
I. J. Lazarus ◽  
...  
Keyword(s):  
Nonlinear Waves ◽  
Low Frequency ◽  
Dusty Plasmas ◽  
Theory Approach ◽  
Satellite Measurements ◽  
Plasma Parameters ◽  
Electron Positron ◽  
Fluid Theory ◽  
Electron Cyclotron Waves ◽  
Electron Acoustic

Using a fluid theory approach, this article provides a comparative study on the evolution of nonlinear waves in dusty plasmas, as well as other plasma environments, viz electron-ion, and electron-positron plasmas. Where applicable, relevance to satellite measurements is pointed out. A range of nonlinear waves from low frequency (ion acoustic and ion cyclotron waves), high frequency (electron acoustic and electron cyclotron waves) in electron-ion plasmas, ultra-low frequency (dust acoustic and dust cyclotron waves) in dusty plasmas and in electron-positron plasmas are discussed. Depending upon the plasma parameters, saw-tooth and bipolar structures are shown to evolve.

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