Study of the higher-order shock excitations in a degenerate quantum plasma (original) (raw)
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Astrophysics and Space Science, 2015
A nonlinear propagation of modified ion-acoustic (mIA) shock waves in a relativistic degenerate plasma (containing inertial viscous positive and negative ion fluids, relativistic electron fluids, and negatively charged immobile heavy ions) has been investigated theoretically. The modified Burgers (mB) and further modified Burgers (FmB) equations have been derived by adopting reductive perturbation technique. The solutions of both mB and FmB equations have been numerically analyzed to characterize the basic features of mIA shock waves. The basic properties (speed, amplitude, width, etc.) of these electrostatic shock waves are found to be significantly modified by the effects of negatively charged static heavy ions and the plasma particle number densities. It is found that the properties of these shock waves obtained from this analysis are significantly different from those obtained from the analysis of standard Burgers equation. The implications of our results in space and interstellar compact objects like non-rotating white dwarfs, neutron stars, etc. are briefly discussed.
Plasma Science and Technology, 2016
A comparative study is carried out for the nonlinear propagation of ion acoustic shock waves both for the weakly and highly relativistic plasmas consisting of relativistic ions and qdistributed electrons and positions. The Burgers equation is derived to reveal the physical phenomena using the well known reductive perturbation technique. The integration of the Burgers equation is performed by the () ¢-G G expansion / method. The effects of positron concentration, ion-electron temperature ratio, electron-positron temperature ratio, ion viscosity coefficient, relativistic streaming factor and the strength of the electron and positron nonextensivity on the nonlinear propagation of ion acoustic shock and periodic waves are presented graphically and the relevant physical explanations are provided.
Ion acoustic shocks in degenerate plasma with trapping in a quantizing magnetic field
In the present investigation, we have studied the effect of trapping on ion acoustic (IA) shock waves with quantizing magnetic field in quantum plasma composed of degenerate electrons/positrons and cold inertial ions. We have derived KdV-Burgers (KdV B) equation by employing the reductive perturbation method and also presented its exact solution. It is observed that positron to electron concentration (via δ), quantizing magnetic field (via ϱ), and finite electron temperature (via T) have a empathetic influence on IA shock structures in the nonlinear regime. Both polarity shock structures have been found in the given system. The work presented in this investigation may be useful to studying the salient feature of IA shocks dynamics in astrophysical dense plasma environments especially in white dwarfs, etc.
Plasma Physics Reports, 2017
The Burgers equation is obtained to study the characteristics of nonlinear propagation of ionacoustic shock, singular kink, and periodic waves in weakly relativistic plasmas containing relativistic thermal ions, nonextensive distributed electrons, Boltzmann distributed positrons, and kinematic viscosity of ions using the well-known reductive perturbation technique. This equation is solved by employing the (G'/G)expansion method taking unperturbed positron-to-electron concentration ratio, electron-to-positron temperature ratio, strength of electrons nonextensivity, ion kinematic viscosity, and weakly relativistic streaming factor. The influences of plasma parameters on nonlinear propagation of ion-acoustic shock, periodic, and singular kink waves are displayed graphically and the relevant physical explanations are described. It is found that these parameters extensively modify the shock structures excitation. The obtained results may be useful in understanding the features of small but finite amplitude localized relativistic ion-acoustic shock waves in an unmagnetized plasma system for some astrophysical compact objects and space plasmas.
Nonlinear Propagation of Dust-Ion-Acoustic Shock Waves in a Degenerate Multi-Species Plasma
International Journal of Cosmology Astronomy and Astrophysics, 2019
The nonlinear propagation of dust-ion-acoustic (DIA) waves in an unmagnetized collisionless degenerate dense plasma (containing degenerate electron, positron, ion fluids and negatively charged dust grains) have been theoretically investigated. The Burgers' equation has been derived by employing the reductive perturbation method and by taking the effect of viscous force in the ion fluid into account. The stationary shock wave solution of Burgers' equation is obtained, and numerically analyzed in order to identify the basic properties of dust-ion-acoustic shock structures. It has been shown that depending on plasma parametric values, the degenerate plasma under consideration supports compressive or rarefactive shock structures. The relevance of our results in astrophysical objects like white dwarfs and neutron stars, which are of scientific interest, are briefly discussed.
Cylindrical and spherical ion-acoustic shock waves in multielectron temperature collisional plasma
Physics of Plasmas, 2004
A rigorous theoretical investigation has been made to study the existence and basic features of the ion-acoustic (IA) shock structures in an unmagnetized, collisionless multi-ion plasma system (containing degenerate electron fluids, inertial positively as well as negatively charged ions, and arbitrarily charged static heavy ions). This investigation is valid for both non-relativistic and ultrarelativistic limits. The reductive perturbation technique has been employed to derive the modified Burgers equation. The solution of this equation has been numerically examined to study the basic properties of shock structures. The basic features (speed, amplitude, width, etc.) of these electrostatic shock structures have been briefly discussed. The basic properties of the IA shock waves are found to be significantly modified by the effects of arbitrarily charged static heavy ions and the plasma particle number densities. The implications of our results in space and interstellar compact objects like white dwarfs, neutron stars, black holes, and so on have been briefly discussed.
A theoretical investigation has been made to study the cylindrical and spherical electron-acoustic shock waves (EASWs) in an unmagnetized, collisionless degenerate quantum plasma system containing two distinct groups of electrons (one inertial non-relativistic cold electrons and other inertialess ultra-relativistic hot electrons) and positively charged static ions. By employing well known reductive perturbation method the modified Burgers (mB) equation has been derived. It is seen that only rarefactive shock waves can propagate in such a quantum plasma system. The effects of degenerate plasma pressure and number density of hot and cold electron fluids, nonplanar geometry, and positively charged static ions are responsible to modify the fundamental properties of EASWs. It is also observed that the properties of planar mB shocks are quite different from those of nonplanar mB shocks. The findings of the present investigation should be useful in understanding the nonlinear phenomena associated with nonplanar EAWs in both space and laboratory plasmas.
Ion-acoustic shock waves in nonextensive electron-positron-ion plasma
Chinese Physics Letters, 2015
A rigorous theoretical investigation has been made of ion-acoustic shock structures in an unmagnetized three-component plasma whose constituents are nonextensive electrons, nonextensive positrons, and inertial ions. The Burgers equation is derived by employing the reductive perturbation method. The effects of electron and positron nonextensivity and ion kinematic viscosity on the properties of these ion-acoustic shock waves are briefly discussed. It has been found that shock waves with positive and negative potential are obtained depending on the plasma parameters. The entailment of our results may be useful to understand some astrophysical and cosmological scenarios like stellar polytropes, hadronic matter and quark-gluon plasma, protoneutron stars, darkmatter halos, etc. where effects of nonextensivity can play the significant roles.
Heavy-and light-nuclei acoustic dressed shock waves in white dwarfs
In this investigation, the evolution of heavy-and light-nuclei acoustic (HLNA) dressed shock waves (DSWs) due to the contribution of higher order of nonlinearity and dissipation effects has been examined in a degenerate quantum plasma composed of inertial heavy as well as light nuclei and inertia-less ultra-relativistic degenerate electrons. By employing the reductive perturbation method, the nonlinear Burgers equation is derived. Further, an inhomogeneous Burgers-type equation accounting for the higher order contributions of nonlinearity and dissipation is also derived. With the insertion of higher order effects, a new humped type or dressed shock structures are evolved. The influence of different plasma parameters on the dynamical evolution of the HLNA-DSWs is examined. It is observed that these plasma parameters play significant role on the characteristics of HLNA-DSWs and their corresponding electric fields. The findings of present investigation may be applicable to provide a new insight to understand the evolution of HLNA-DSWs in different dense astrophysical regions such as white dwarfs.
Journal of Plasma Physics, 2013
The 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.