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1.
The combined effects of the obliqueness and nonextensive electrons are incorporated in the study of ion acoustic (IA) waves in a magnetized plasma. The propagation properties of two possible modes (in the linear regime) are investigated. It is found that the electron nonextensivity decreases the phase velocities of both two modes. Also obliqueness leads to increase of separation between two modes. The nonlinear evolution of IA solitary waves is governed by an energy-like equation. The influence of electron nonextensivity, obliqueness and electron population on the existence domain of solitary waves and the soliton characteristics are examined. It is shown that the existence domain of the IA soliton and its profile is significantly depended on the deviation of electrons from thermodynamic equilibrium and obliqueness. Interestingly, the present model supports compressive as well as rarefactive IA solitary waves. Our finding should elucidate the nonlinear electrostatic structures that propagate in astrophysical and cosmological plasma scenarios where nonextensive and magnetized plasma can exist; like instellar plasma stellar polytropes, solar neutrino problem, peculiar velocities of galaxy clusters, dark-matter halos, protoneutron stars, hadronic matter, quark-gluon plasma, and magnetosphere, etc. 相似文献
2.
Obliquely propagating nonlinear structures in dense dissipative electron positron ion magnetoplasmas
Nonlinear electrostatic waves in dense dissipative magnetized electron-positron-ion (e-p-i) plasmas are investigated employing
the quantum hydrodynamic model. In this regard, Zakharov Kuznetsov Burgers (ZKB) equation is derived in dense plasmas using
the small amplitude perturbation expansion method. It is observed that obliqueness, positron concentration, kinematic viscosity,
and the ambient magnetic field significantly alter the structure of nonlinear quantum ion acoustic waves in dense dissipative
e-p-i magnetoplasmas. The present study may be useful to understand the nonlinear propagation characteristics of electrostatic
shock structures in dense astrophysical systems where the quantum effects are expected to dominate. 相似文献
3.
A theoretical investigation is carried out to analyse the propagation of ion acoustic (IA) waves in a magnetized bi-ion plasma having two populations of fluid ions and kappa-distributed electrons. The propagation properties of all possible modes (in the linear regime) are investigated. The nonlinear evolution of the IA solitary waves is governed by a Korteweg-de Vries (KdV)-like equation. The influence of obliqueness, magnitude of the magnetic field, ion polarity and electron superthermality on the IA waves is then examined. Our findings should aid in understanding the nonlinear electrostatic excitations that may propagate in spatial magnetized plasmas. 相似文献
4.
N. R. Kundu M. M. Masud K. S. Ashrafi A. A. Mamun 《Astrophysics and Space Science》2013,343(1):279-287
A rigorous theoretical investigation has been made on multi-dimensional instability of obliquely propagating electrostatic dust-ion-acoustic (DIA) solitary structures in a magnetized dusty electronegative plasma which consists of Boltzmann electrons, nonthermal negative ions, cold mobile positive ions, and arbitrarily charged stationary dust. The Zakharov-Kuznetsov (ZK) equation is derived by the reductive perturbation method, and its solitary wave solution is analyzed for the study of the DIA solitary structures, which are found to exist in such a dusty plasma. The multi-dimensional instability of these solitary structures is also studied by the small-k (long wave-length plane wave) perturbation expansion technique. The combined effects of the external magnetic field, obliqueness, and nonthermal distribution of negative ions, which are found to significantly modify the basic properties of small but finite-amplitude DIA solitary waves, are examined. The external magnetic field and the propagation directions of both the nonlinear waves and their perturbation modes are found to play a very important role in changing the instability criterion and the growth rate of the unstable DIA solitary waves. The basic features (viz. speed, amplitude, width, instability, etc.) and the underlying physics of the DIA solitary waves, which are relevant to many astrophysical situations (especially, auroral plasma, Saturn’s E-ring and F-ring, Halley’s comet, etc.) and laboratory dusty plasma situations, are briefly discussed. 相似文献
5.
H. Alinejad 《Astrophysics and Space Science》2012,337(2):637-643
A theoretical investigation is carried out for understanding the basic features of oblique propagation of linear and nonlinear
ion-acoustic waves subjected to an external magnetic field in an electron-positron-ion plasma which consists of a cold magnetized
ion fluid, Boltzmann distributed positron, and electrons obeying a trapped distribution. In the linear regime, two dispersion
curves are obtained. It is shown that the positron concentration causes the both modes to propagate with smaller phase velocities.
Then, owing to the presence of resonant electrons, the modified Korteweg-de Vries equation describing the nonlinear dynamics
of small but finite amplitude ion-acoustic waves is derived. It is found that the effects of external magnetic field (obliqueness),
trapped electrons, positron concentration and temperature ratio significantly modify the basic features of solitary waves. 相似文献
6.
A.A. Mamun 《Astrophysics and Space Science》1998,260(4):507-514
A rigorous theoretical investigation has been made of obliquely propagating dust-acoustic solitary structures in a cold magnetized two-ion-temperature dusty plasma consisting of a negatively charged, extremely massive, cold dust fluid and ions of two different temperatures. The reductive perturbation method has been employed to derive the Korteweg-de Vries (K-dV) equation which admits a solitary wave solution for small but finite amplitude limit. It has been shown that the presence of second component of ions modifies the nature of dust-acoustic solitary structures and may allow rarefactive dust-acoustic solitary waves (solitary waves with density dip) to exist in such a dusty plasma system. The effects of obliqueness and external magnetic field on the properties of these dust-acoustic solitary structures are also briefly discussed. 相似文献
7.
Arbitrary amplitude electron acoustic (EA) solitary waves in a magnetized nonextensive plasma comprising of cool fluid electrons, hot nonextensive electrons, and immobile ions are investigated. The linear dispersion properties of EA waves are discussed. We find that the electron nonextensivity reduces the phase velocities of both modes in the linear regime: similarly the nonextensive electron population leads to decrease of the EA wave frequency. The Sagdeev pseudopotential analysis shows that an energy-like equation describes the nonlinear evolution of EA solitary waves in the present model. The effects of the obliqueness, electron nonextensivity, hot electron temperature, and electron population are incorporated in the study of the existence domain of solitary waves and the soliton characteristics. It is shown that the boundary values of the permitted Mach number decreases with the nonextensive electron population, as well as with the electron nonextensivity index, q. It is also found that an increase in the electron nonextensivity index results in an increase of the soliton amplitude. A comparison with the Vikong Satellite observations in the dayside auroral zone is also taken into account. 相似文献
8.
Linear and nonlinear analysis of low frequency magnetoacoustic waves propagating at an angle θ with the ambient magnetic field are investigated in dense electron-positron-ion (e-p-i) plasmas using the quantum magnetohydrodynamic
(QMHD) model. In this regard, a quantum Kadomtsev-Petviashvili-Burgers (KPB) equation is derived in the small amplitude limit.
The stability of KPB equation is also presented. The variation of the nonlinear fast and slow magnetoacoustic shock waves
with the positron concentration, kinematic viscosity, obliqueness parameter θ, and the magnetic field, are also investigated. It is observed that the aforementioned plasma parameters significantly modify
the propagation characteristics of two dimensional nonlinear magnetoacoustic shock waves in dissipative quantum magnetoplasmas.
The relevance of the present investigation with regard to dense astrophysical environments is also pointed out. 相似文献
9.
Mehran Shahmansouri 《Astrophysics and Space Science》2013,344(1):153-160
Dust-acoustic (DA) solitary waves are investigated in a magnetized dusty plasma comprising cold dust fluid and kappa-distributed ions and/or electrons. The influence of suprathermal particles, obliqueness, and ion temperature on the DA solitary waves is investigated. We find that only negative DA solitary waves will be excited in this model. Also it is shown that the amplitude of the DA solitary wave decreases with deviation of electrons or ions from Maxwellian distribution via decrease of κ e or κ i . The effect of the temperature of the ion decreases with the amplitude and steepness of the solitary wave front. 相似文献
10.
A theoretical investigation has been made on obliquely propagating dust-ion-acoustic solitary waves (DIASWs) in magnetized
dusty electronegative plasma containing Boltzmann electrons, trapped negative ions, cold mobile positive ions, and arbitrarily
charged stationary dust. The reductive perturbation method has been employed to derive the modified Zakharov-Kuznetsov (MZK)
equation which admits solitary wave solution under certain conditions. The multi-dimensional instability of these solitary
waves is also studied by the small-k (long wavelength plane wave) perturbation-expansion technique. The basic properties (speed, amplitude, width, instability,
etc.) of small but finite amplitude DIASWs are significantly modified by the effects of external magnetic field, obliqueness,
polarity of dust, and trapped negative ions. The implications of our results in space and laboratory plasmas are briefly discussed. 相似文献
11.
A theoretical investigation has been made of obliquely propagating dust-acoustic solitary waves in a magnetized three-component dusty plasma, which consists of a negatively charged dust fluid, ions, and nonextensive electrons. The reductive perturbation method has been employed to derive the Korteweg-de Vries equation which admits a solitary wave solution. It has been shown that the combined effects of external magnetic field (obliqueness), ions, and electron nonextensivity change the behavior of these electrostatic solitary structures that have been found to exist with positive and negative potential in this dusty plasma model. The implications of our results in astrophysical and cosmological scenarios like vicinity of the Moon, magnetospheres of Jupiter and Saturn, dark-matter halos, hadronic matter, quark-gluon plasma, protoneutron stars, stellar polytropes etc. have been mentioned. 相似文献
12.
H. G. Abdelwahed 《Astrophysics and Space Science》2012,341(2):491-500
Using the Viking Satellite observations data in the dayside auroral zone, a theoretical investigation is carried out for contribution of the higher-order nonlinearity to nonlinear obliquely electron-acoustic solitary waves (EASWs) in a magnetized collisionless plasma consisting of a cold electron fluid and non-thermal hot electrons obeying a non-thermal distribution, and stationary ions. A Zakharov–Kuznetsov (ZK) equation that contains the lowest-order nonlinearity and dispersion is derived from the lowest order of perturbation and a linear inhomogeneous (ZK-type) equation that accounts for the higher-order nonlinearity and dispersion is obtained. A stationary solution for equations resulting from higher-order perturbation theory has been found using the renormalization method. The effects of the external magnetic field and the obliqueness are found to significantly change the higher-order properties (viz. the amplitude, width, electric field and energy) of the EASWs. The effect of higher-order nonlinearity on the amplitude and width of the soliton are also discussed. A comparison with the Viking Satellite observations in the dayside auroral zone are taken into account. 相似文献
13.
A theoretical investigation has been made of electrostatic solitary structures in an electron-positron-ion (e-p-i) plasma, taking nonextensive electrons and nonextensive positrons. By employing the reductive perturbation method, the basic characteristics of ion-acoustic (IA) solitary waves (SWs) in a three-component e-p-i plasma (consisting of negatively charged nonextensive electrons, positively charged nonextensive positrons, and ions) have been addressed. The Korteweg-de Vries (K-dV), modified K-dV (mK-dV), and Gardner equations are derived and their numerical solutions are obtained. It has been shown that the combined effects of electron nonextensivity, positron nonextensivity, and ions significantly modify the behavior of these electrostatic solitary structures that have been found to exist with positive and negative potential in this plasma model. The present analysis may be useful to understand and demonstrate the dynamical properties of IA SWs in different astrophysical and cosmological scenarios (viz. stellar polytropes, hadronic matter and quark-gluon plasma, protoneutron stars, dark-matter halos, etc.). 相似文献
14.
S. K. El-Labany M. Shalaby R. Sabry L. S. El-Sherif 《Astrophysics and Space Science》2012,340(1):101-108
A theoretical investigation is carried out for understanding the properties of electron-acoustic potential structures (i.e.,
solitary waves and double-layers) in a magnetized plasma whose constituents are a cold magnetized electron fluid, hot electrons
obeying a nonthermal distribution, and stationary ions. For this purpose, the hydrodynamic equations for the cold magnetized
electron fluid, nonthermal electron density distribution, and the Poisson equation are used to derive the corresponding nonlinear
evolution equation; modified Zakharov–Kuznetsov (MZK) equation, in the small amplitude regime. The MZK equation is analyzed
to examine the existence regions of the solitary pulses and double-layers. It is found that rarefactive electron-acoustic
solitary waves and double-layers strongly depend on the density and temperature ratios of the hot-to-cold electron species
as well as the nonthermal electron parameter. 相似文献
15.
C. Rozina N. L. Tsintsadze M. Jamil A. Rasheed S. Ali 《Astrophysics and Space Science》2014,353(2):485-491
By employing the anisotropic plasma distribution function, the stability of circularly polarized electromagnetic (EM) waves is studied in a relativistically hot electron-positron-ion (e-p-i) plasma, investigating two specific scenarios. First, linear dispersion relations associated with the transverse EM waves are analyzed in different possible frequency regimes. The expression of the aperiodic hydrodynamic instability is obtained and numerically the transverse EM modes are shown to grow exponentially. Secondly, we have found that the transverse electromagnetic wave interact with a collisionless anisotropic e-p-i plasma and damp through the nonlinear Landau damping phenomena. Taking the effects of the latter into consideration, a kinetic nonlinear Schrödinger equation is derived with local and nonlocal nonlinearities, computing the damping rates. The present work should be helpful to understand the linear and nonlinear properties of the intense EM waves in hot relativistically astrophysical plasmas, e.g., pulsars, black holes, neutron stars, etc. 相似文献
16.
Nonlinear ion acoustic solitary wave structures in electron-positron-ion (e-p-i) magnetized rotating plasmas is studied. The electron and positron species are assumed to be nonthermal and follow the kappa distribution function. The Korteweg de Vries (kdV) equation is derived by employing the reductive perturbation technique for solitary wave in the nonlinear regime. The variation in the amplitude and width of the solitary wave are discussed with the effects of positron concentration, temperature ratio of kappa distributed electrons to positrons, spectral index of the positrons, direction of propagation of the wave with magnetic field and effective gyrofrequency of the rotating nonthermal plasmas. The numerical results are also presented for illustration. 相似文献
17.
Nonlinear dynamics of electron-acoustic solitary waves in a magnetized plasma whose constituents are cold magnetized electron fluid, hot electrons featuring Tsallis distribution, and stationary ions are examined. The nonlinear evolution equation (i.e., Zakharov–Kuznetsov (ZK) equation), governing the propagation of EAS waves in such plasma is derived and investigated analytically and numerically, for parameter regimes relevant to the dayside auroral zone. It is revealed that the amplitude, strength and nature of the nonlinear EAS waves are extremely sensitive to the degree of the hot electron nonextensivity. Furthermore, the obtained results are in good agreement with the observations made by the Viking satellite. 相似文献
18.
A theoretical investigation is made on the formation as well as basic properties of dust-ion-acoustic (DIA) shock waves in a magnetized nonthermal dusty plasma consisting of immobile charge fluctuating dust, inertial ion fluid and nonthermal electrons. The reductive perturbation method is employed to derive the Korteweg-de Vries-Burgers equation governing the DIA shock waves. The combined effects of external static magnetic field, obliqueness, nonthermal electron distribution and dust charge fluctuation on the DIA shock waves are also investigated. It is shown that the dust charge fluctuation is a source of dissipation, and is responsible for the formation of the DIA shock waves. It is also observed that the combined effects of obliqueness, nonthermal electron distribution and dust charge fluctuation significantly modify the basic properties of the DIA shock waves. The implications of our results in space and laboratory dusty plasma situations are briefly discussed. 相似文献
19.
A rigorous theoretical investigation has been made on the obliquely propagating dust-acoustic (DA) waves in a magnetized dusty plasmas consisting of distinct temperature q-distributed electrons with distinct strength of nonextensivities, nonthermal ions and negatively charged mobile dust grains, and analyzed by deriving the Zakharov-Kuznetsov equation. It is found that the characteristics and the properties of the DA solitary waves (DASWs) are significantly modified by the external magnetic field, relative temperature ratio of ions, relative number densities of electrons as well as ions, the nonextensivity of electrons, nonthermality of ions and the obliqueness of the system. The possible implications of the results obtained from this analysis in space and laboratory dusty plasmas are briefly addressed. 相似文献
20.
S. K. El-Labany E. F. El-Shamy S. K. El-Sherbeny 《Astrophysics and Space Science》2014,351(1):151-158
The oblique collision of nonlinear quantum dust-acoustic (NQDA) solitary waves in a three-dimensional (3D) magnetized dense dusty plasma is investigated. Furthermore, two coupled Kortwege–de Vries equations for describing our model and the analytical phase shifts after the oblique collision of two NQDA solitary waves are derived using the extended Poincaré–Lighthill–Kuo (PLK) method. The modification in the phase shift and the trajectory of the NQDA solitary waves structures due to the inclusion of oblique collision and external magnetic field are discussed numerically. The numerical results are applied to high density astrophysical situations such as in superdense white dwarfs. 相似文献