Search

We considered a dense plasma containing electrons, positrons, ions and dust particles in background magnetic and gravitational fields alongside collisional effects for the heavier species (ions and dust particles). Such plasmas are found in magnetars, black hole accretion disks, and so on. The quantum hydrodynamic (QHD) model was used to construct the governing equations of the plasma. Relativistic degeneracy pressure is taken as the equation of state for the electrons and positrons. Effects of exchange-correlation potential were also considered for the lighter species. We employed the reductive perturbation method (RPM) in order to obtain the Zakharov–Kuznetsov (ZK) equation describing 3-D ion acoustic waves (IAWs) with minimal lateral perturbations. Low order analytical solutions allow us to understand the parametric dependence of said structures. Our newly developed numerical technique: homotopy assisted symbolic simulation (HASS) sheds light on the gradual evolution of higher order stationary formations in the system. The results thus obtained can potentially explain certain astrophysical phenomena as well as dense laboratory plasmas. [ABSTRACT FROM AUTHOR]

In this work, we used the semi-Lagrangian method and the Vlasov code to study the instabilities in a quantum plasma with 1-D temperature anisotropy. Taking the Fermi–Dirac type of distribution function (DF) and using the semi-Lagrangian Vlasov code, we studied the gradual evolution of density and kinetic energy in a degenerate plasma with quantum effects. In this collisionless plasma, adiabatic compression will be along the direction of wave propagation and will lead to temperature anisotropy of the electron distribution that varies along the direction of wave propagation. The findings will find application for dense plasma at finite temperature as in laser-produced plasmas, fusion plasma, as well as solar plasmas. [ABSTRACT FROM AUTHOR]

In this article, we investigate the linear and nonlinear behavior of ion-plasma waves in a two-component plasma containing ions and dust particles. We have studied the linear dispersion characteristics, nonlinear KdV solitons, and amplitude modulated electrostatic waves. Such ion-plasma wave modes in dust-ion plasma have been theoretically investigated by incorporating quantum diffraction and relativistic effects. Numerical analysis of the linear dispersion relation with variations of different parameters has been carried out. By employing the reductive perturbation technique the KdV equation describing the small amplitude solitary profile has been studied. Using the standard multiple scale perturbation method, a nonlinear Schrödinger (NLS) equation has been derived by including quantum and relativistic effects, which describes the nonlinear evolution of the ion-plasma waves in dust-ion plasma. The wave is found to become modulationally unstable beyond certain critical wavenumber. The critical wavenumber and the growth rate of modulational instability are shown to depend significantly on the relativistic motion of plasma particles and the quantum diffraction effect. The results presented in the article are expected to be helpful for understanding the propagation of finite amplitude ion-plasma waves in some laboratory and astrophysical plasma systems. PACS—52.59.Hq, 67.10.Jn, 52.20 −j, 52.25 −b, 52.30 −d, 52.35 Mw, 52.65 Vv [ABSTRACT FROM AUTHOR]

Bifurcation analysis and dynamical system studies are carried out to find the stability regime and chaotic scenario in electron acoustic waves in relativistic degenerate plasma. We have obtained the quantum hydrodynamic model and obtain the Korteweg–de Vries equation describing the nature and characteristics of solitary structures. The amplitude modulated envelop soliton formation due to external perturbations has been studied by analyzing the nonlinear Schrodinger equation. Further to study the stability factors and the parametric range for such stability, the dynamical system is studied and bifurcation analysis has been carried out. The chaotic behavior of the system is studied through largest Lyapunov exponent (LLE). This work will find application in theoretically predicting the stable modes in many solar plasma and stellar plasma applications and in laser plasma in future. [ABSTRACT FROM AUTHOR]

In this work, we start with the ion-acoustic waves in galactic plasma with the degenerate matter. We use the reductive perturbation technique to derive the spherical Kadomtsev–Petviashvili (SKP) equation. We next employ homotopy-aided symbolic simulation (HASS) to study the evolution of the spherical solitary wavefront. We compare the results obtained by HPM and RPT. To understand how the system behaves, we transform the evolutionary equations into a dynamical system. The phase portraits and the superperiodic waves reflect on the intricate processes within the plasma and determine the stability criteria and possible situations of chaos. The work will find applications in many astrophysical observations, such as electrostatic wave modes, gamma-ray bursts, and double-layer solitons. PACS—95.30.Qd, 52.65.-y, 52.35.-g, 52.35.Tc. [ABSTRACT FROM AUTHOR]

In this article, we have studied the electron acoustic waves in a magnetized plasma containing Kappa distributed ions which are streaming with high velocity within the plasma and under the action of external force. We employed the homotopy perturbation method (HPM) to obtain the graphical plots of solitary structures and their evolution into an envelope soliton. Analytically, we obtained the linear dispersion relation and studied its characteristics. Further, we derived the Korteweg–De Vries (KdV) equation using the reductive perturbation technique and studied the parametric dependence on the KdV solitary profile. These findings augment the homotopy results. The analytical and simulation results thus obtained will be helpful in interpretating and identifying electron acoustic wave (EAW) modes in such a plasma system. [ABSTRACT FROM AUTHOR]

In this work, we start with the quantum hydrodynamic model equations for two temperature-populated electrons in a dense plasma with quantum effects. We obtain the KdV equation for the electron acoustic (EAW) mode. The EAW self-interacts to form a rogue wave-type envelop soliton which is described by the nonlinear Schrodinger (NLS) equation. To study the stability criteria, we transform the KdV and NLS equations into its dynamical system counterparts and analyze the phase portraits and carry out the bifurcation analysis. The possibility of hyperchaos is discussed with reference to rogue waves. The finding will be helpful in laser plasma interactions, microelectronics, as well as beam plasma physics and fusion technology. [ABSTRACT FROM AUTHOR]

A semiconductor p-n junction diode with heavy doping under consideration is kept in forward biased condition. These are oppositely propagating electron and hole currents. These two streams interact among themselves and result in recombination, which supplies additional energy to the system. Such thermal energy creates additional electrical fluctuations, which exists long after the interaction has taken place. We have carried out an analytical investigation with numerical techniques as well as carried out a simulation of the wave–wave interaction in semiconductor junction diodes. In terms of signal transmission and operation of semiconductor device, such a theoretical study is important. [ABSTRACT FROM AUTHOR]

By employing a quantum hydrodynamic (QHD) model with appropriate boundary conditions, the nonlinear self-interaction of an electrostatic surface wave on otherwise homogeneous semibounded plasma with degeneracy effects is investigated. It has been found that a part of the second harmonic generated through self-interaction does not have a true surface wave feature but propagates obliquely away from the plasma–vacuum interface into the bulk of the plasma. Such a situation is obtained in laser–plasma interaction during surface etching, plasma processing, and so on. In this article, we study the harmonics generation mechanism, associated Lagrangian chaos, and harmonic conversation rate when an intense laser is incident on an unmagnetized plasma. The dense plasma displays quantum diffraction effects and other quantum statistical effects. We made use of perturbative analysis for the field quantities. The findings will help workers dealing with laser–plasma interaction so as to enhance the tendency of harmonic generation and energy localization. [ABSTRACT FROM AUTHOR]