Electromagnetic solitons in degenerate relativistic electron–positron plasma (original) (raw)
Large Amplitude Localized Structures in a Relativistic Electron-Positron Ion Plasma
Physical Review Letters, 1994
The nonlinear propagation of circularly polarized electromagnetic waves with relativistically strong amplitude in an unmagnetized cold electron-positron ion plasma is investigated. The possibility of finding soliton solutions in such a plasma is explored. It is shown that the presence of a small fraction of massive ions in the plasma leads to stable localized solutions.
The Astrophysical Journal, 2014
The propagation of electrostatic waves in a dense magnetized electron-positron-ion (EPI) plasma with nonrelativistic and ultrarelativistic degenerate electrons and positrons is investigated. The linear dispersion relation is obtained for slow and fast electrostatic waves in the EPI plasma. The limiting cases for ion acoustic wave (slow) and ion cyclotron wave (fast) are also discussed. Using the reductive perturbation method, two-dimensional propagation of ion acoustic solitons is found for both the nonrelativistic and ultrarelativistic degenerate electrons and positrons. The effects of positron concentration, magnetic field, and mass of ions on ion acoustic solitons are shown in numerical plots. The proper form of Fermi temperature for nonrelativistic and ultrarelativistic degenerate electrons and positrons is employed, which has not been used in earlier published work. The present investigation is useful for the understanding of linear and nonlinear electrostatic wave propagation in the dense magnetized EPI plasma of compact stars. For illustration purposes, we have applied our results to a pulsar magnetosphere.
Perpendicular propagating electromagnetic envelope solitons in electron-positron-ion plasma
Physics of Plasmas, 2010
The nonlinear amplitude modulation of electromagnetic waves propagating perpendicular to the direction of ambient magnetic field in a uniform collisionless magnetized electron-positron-ion plasma is studied. The Krylov-Bogoliubov-Mitropolsky perturbation method is employed to derive nonlinear Schrödinger equation, which describes the amplitude dynamics of perturbed magnetic field. The modulation instability criterion reveals that the low frequency mode is always stable, whereas the high frequency mode becomes modulationally unstable for certain ranges of wave number and positron-to-electron density ratio. Furthermore, the positron-to-electron density ratio as well as the strength of ambient magnetic field is found to have significant effect on the solitary wave solutions of the nonlinear Schrödinger equation, namely, dark and bright envelope solitons.
Dressed solitons in quantum electron-positron-ion plasmas
Physics of Plasmas, 2009
Nonlinear propagation of quantum ion acoustic waves in a dense quantum plasma whose constituents are electrons, positrons, and positive ions is investigated using a quantum hydrodynamic model. The Korteweg-de Vries equation is derived using reductive perturbation technique. The higher order inhomogeneous differential equation is obtained for the dressed soliton. The dynamical equation for dressed soliton is solved using the renormalization method. The conditions for the validity of the higher order correction are described. The effects of quantum parameter, positron concentration, electron to positron Fermi temperature ratio, and soliton velocity on the amplitude and width of the dressed soliton are studied.
Electrostatic Solitary Waves in Relativistic Degenerate Electron–Positron–Ion Plasma
IEEE Transactions on Plasma Science, 2015
The linear and nonlinear properties of ion acoustic excitations propagating in warm dense electron-positron-ion plasma are investigated. Electrons and positrons are assumed relativistic and degenerate, following the Fermi-Dirac statistics, whereas the warm ions are described by a set of classical fluid equations. A linear dispersion relation is derived in the linear approximation. Adopting a reductive perturbation method, the Korteweg-de Vries equation is derived, which admits a localized wave solution in the form of a small-amplitude weakly super-acoustic pulse-shaped soliton. The analysis is extended to account for arbitrary amplitude solitary waves, by deriving a pseudoenergy-balance like equation, involving a Sagdeev-type pseudopotential. It is shown that the two approaches agree exactly in the small-amplitude weakly super-acoustic limit. The range of allowed values of the pulse soliton speed (Mach number), wherein solitary waves may exist, is determined. The effects of the key plasma configuration parameters, namely, the electron relativistic degeneracy parameter, the ion (thermal)-to-the electron (Fermi) temperature ratio, and the positron-to-electron density ratio, on the soliton characteristics and existence domain, are studied in detail. Our results aim at elucidating the characteristics of ion acoustic excitations in relativistic degenerate plasmas, e.g., in dense astrophysical objects, where degenerate electrons and positrons may occur. Index Terms-Plasma oscillations, plasma waves. I. INTRODUCTION R ECENTLY there has been a great deal of interest in elucidating the dynamics of collective processes in degenerate dense plasmas, commonly found in dense astrophysical objects (e.g., white and brown dwarfs, neutron stars, and magnetars), in the core of giant planets (e.g., Jovian planets), which can Manuscript
On the Formation of Solitons in an Isothermal Relativistic Plasma with Positive and Negative Ions
1994
We have studied the phenomenon of solitary wave formation in a relativistic plasma having both positive and negative ions. The state of the plasma is assumed to be isothermal and ions are considered to be warm. The phase velocity, width and amplitude of the soliton are explicitly obtained as functions of σα, σβ , nβ0/nα0, uα0/c, uβ0/c and Q, where σα and σβ are the temperatures of the two kinds of ions, nα0 and nβ0 are the respective equilibrium densities, uα0 and uβ0 are the corresponding streaming velocities and Q is the mass ratio of the negative and positive ions.
Weakly relativistic solitons in a magnetized ion-beam plasma in presence of electron inertia
Physics of Plasmas, 2011
The relativistic compressive solitons of fast ion-acoustic mode are established in this magnetized plasma for the introduction of relativistic beam when QЈ͑=m b / m i ͒ Ͼ 1 or Ͻ1 subject to v s0 − v b0 = U d sin ͑v s0 = ion initial streaming, v b0 = beam initial streaming, and U d is the beam drift perpendicular to the direction of magnetic field͒. The lighter concentration of beam ions ͑QЈ Ͻ 1͒ in the plasma admits slower variation in amplitudes after some critical N b ͑=beam density͒ for all ͑cos ͒. Further, it is shown that under smaller relativistic effect ͑v b0 / c = 0.10 and v s0 / c = 0.10͒ for small concentration of beam ions ͑QЈ Ͻ 1͒ in the plasma, the growth of soliton amplitude becomes smaller with the increase of N b . But to the contrary, for heavier concentration of beam ions QЈ͑Ͼ1͒, the amplitudes of solitons decay considerably with QЈ growing sharply to a maximum in the vicinity of QЈ Ϸ 1.
Physics of Plasmas, 2016
A system of nonlinear one-dimensional equations of the electron hydrodynamics with Maxwell's equations was developed to describe electromagnetic (EM) solitons in plasma with nonthermal electrons. Equation of vector potential was derived in relativistic regime by implementing the multiple scales technique, and their solitonic answers were introduced. The allowed regions for bright and dark electromagnetic solitons were discussed in detail. Roles of number density of nonthermal electrons, temperature of electrons, and frequency of fast participate of vector potential on the Sagdeev potential and properties of EM soliton were investigated. Results show that with increasing the number of nonthermal electrons, the amplitude of vector potential of bright solitons increases. By increasing the number of nonthermal electrons, dark EM solitons may be changed to bright solitons. Increasing the energy of nonthermal electrons leads to generation of high amplitude solitons. Published by AIP Publishing.