Self-gravitating Dusty Plasma Research Articles

Dust acoustic waves potentially originate in a self-gravitating magnetized dusty plasma

The dynamics of dust acoustic waves (DAWs) in a collision-magnetized dusty plasma are still unclear. To achieve this, we investigate the dynamics of a plasma system consisting of Boltzmann-distributed electrons and ions, and fluid-negative dust particles. The generalized hydrodynamic model of coupled particles is reduced using conventional reductive perturbation theory to a single evolution equation known as the complex Ginzburg-Landau (CGL) equation. Our results show that the energy of rogue waves (RW) is increased by high-energy electrons and decreased by high-energy ions for small polarization parameter. We also observed that the energy of rogue waves increased with decreasing the polarization parameter and the gravitational force coefficient, while increasing dust grain concentration enhances the wave energy. The application of this study to dusty magnetoplasma in space and laboratory plasmas is pointed out.

Dust-acoustic waves in a self-gravitating nonextensive dusty plasma

Dust-acoustic waves in a self-gravitating nonextensive dusty plasma

Twisted dust-acoustic waves in a self-gravitating dusty plasma with nonextensive q-distributed electrons and ions

We have investigated the twisted dust-acoustic waves (TDAWs) in an electrostatic self-gravitating dusty plasma whose electrons and ions are modelled by nonextensive q-distribution function while massive dust particles are Maxwellian distributed. A well-known kinetic theory is employed for this purpose where perturbed distribution function, electrostatic and gravitational potentials are expressed with Laguerre–Gauss functions. The governing equations of kinetic theory are solved together under paraxial approximations. The dispersion relations and instability growth rates are obtained for two situations; a) super-extensivity (q < 1) and b) sub-extensivity (q > 1). Significant modifications concerning the wave frequencies and growth rates are presented with respect to self-gravitation parameter, twist parameter, nonextensive parameter and streaming speed. It is observed that wave frequency and growth rate of TDAWs reduces in the presence of self-gravitating effects. Furthermore, the growth rates exhibit a significant enhancement in amplitude with the increase in twist parameter, q-parameter and streaming speed. Our present results may have applications in interstellar dust clouds and in the dusty plasma environments of Halley’s Comet.

Dynamics and head-on collisions of multidimensional dust acoustic shock waves in a self-gravitating magnetized electron-depleted dusty plasma

The dynamics and collisions of dust acoustic (DA) shock excitations traveling in opposite directions are theoretically investigated in a three-dimensional self-gravitating magnetized electron-depleted dusty plasma whose ingredients are extremely warm positively and negatively charged massive dust grains as well as ions that follow the q-nonextensive distribution. A linear analysis and the extended Poincare–Lighthill–Kuo method are used to derive the dispersion relation, the two-sided Korteweg–de Vries Burgers equations, and the phase shift that occurs due to the wave interaction. It is found that gravitation introduces Jeans-like instability, reduces the wave damping rate, decays the aperiodic oscillatory structure of DA excitations, and strongly affects the amplitude, steepness, and occurrence of monotonic compressive and rarefactive shocks. Numerical simulations also highlighted the stabilizing role of the magnetic field and the singularities of the collision process of monotonic shock fronts as well as the undeniable influence of viscosity, ion nonextensivity, and obliqueness between counter-traveling waves on the phase shift and collision profiles. The present results may be useful to better understand interactions of dust acoustic shock waves in the laboratory and astrophysical scenarios, such as dust clouds in the galactic disk, photo-association regions separating H II regions from dense molecular clouds, Saturn's planetary ring, and Halley Comet.

Influence of ions nonextensivity on the dynamics of dust acoustic double layers in a magnetized self-gravitating dusty plasma

The existence and polarity of dust acoustic double layers (DADLs) in a magnetized self-gravitating opposite polarity dusty plasma (OPDP) have been investigated. The constituents of the OPDP model are two species of positively and negatively charged dust grains, Maxwellian electrons, and nonextensive distributed ions. Employing the reduction perturbation method to solve basic fluid equations for dust grains, the extended Korteweg-de Vries (E-KdV) equation was derived, and its solution was extracted and analyzed. Results show that DADLs behavior is influenced by several new relevant configurational parameters, including the nonextensivity of ions, strength, and direction of the static magnetic field, as well as the self-gravitational field. In the proposed OPDP model positive and negative double-layer polarities may be formed. The polarity of OPDP is severely affected by the nonextensivity of plasma ions and the mass ratio of positive dusts to negatives. Results of higher-order nonlinear equation for solitary structure deny the presence of solitons in the physical condition of modeled plasma. In this work, simultaneous effects of an external magnetic field, self-gravitational force, and plasma ions’ nonextensivity have been studied extensively, which can be applied in various material processing plasmas, fusion plasmas, to space plasmas such as cometary tails, and Earth’s mesosphere.

Dust-acoustic solitary and periodic waves in magnetized self-gravito-electrostatic opposite polarity dusty plasmas

Dust-acoustic (DA) solitary and periodic waves investigations were performed in a magnetized self-gravitating dusty plasma consisting of negatively and positively charged dust grains in the presence of inertialess ions and electrons. The Korteweg–de Vries–Burger (KdVB) equation has been derived. The numerical investigations revealed the compressive or rarefactive DA solitons depending on the plasma parameters. The nonlinear homoclinic and periodic trajectories from the KdVB equation were obtained for the phase portrait profiles when employing the phase plane theory of dynamical systems. The periodic wave solution depends also on the system parameters. The present results are considered to be beneficial in understanding the nonlinear structures in experimental devices and different astrophysical environments such as the Earth’s mesosphere, cometary tails, and Jupiter’s magnetosphere.

Dust-acoustic solitary waves in a self-gravitating warm opposite polarity dusty plasma

A theoretical investigation is made to study the propagation of dust-acoustic solitary waves in a general and realistic self-gravitating dusty plasma system containing positively as well as negatively charged warm dust species and nonthermally distributed ion species. The standard reductive perturbation method is employed to derive the Korteweg–de Vries equation which admits the solitary wave solution. The parametric regimes for the existence of dust-acoustic solitary waves associated with electrostatic and self-gravitational potentials are obtained. It is shown that the population of nonthermal ion species significantly modifies the basic features of the dust-acoustic solitary waves. The significant effects of ratios of mass, temperature, and number density of positively charged dust species to those of negatively charged one on the basic properties (namely, phase speed, polarity, amplitude, and width) of the dust-acoustic solitary waves are also identified. A brief comparison between electrostatic and self-gravitational solitary potential structures is also made. The implications of our results to different space and laboratory dusty plasma environments, where opposite polarity dust grains are observed, are briefly discussed.

The effect of negative ion population on dust acoustic wave propagation in a self gravitating Lorentzian dusty plasma

A theoretical investigation into the effect of negative ion population on dust acoustic wave propagation is presented in a self-gravitating dusty plasma consisting of electrons, negative ions, positive ions, and charged dust grains. The kappa distributed suprathermal electrons and Maxwellian ions are assumed. The inertial dust grain is assumed to have a variable charge which is negative or positive in the equilibrium condition depending on the population density of negative ion. A general fluid dispersion relation is derived by using continuity, momentum, and Poissons equations for electrostatic potential as well as gravitational potential. The analysis shows that the higher negative ion and suprathermal electron population favored the reduction of the decay rate when the equilibrium dust charge is negative. On the other hand, when the negative ion population increases, the equilibrium dust charge becomes positive. In this case, the negative ion and suprathermal electron population enhance the decay rate.

Acoustic Modes of Multi-Ion Dusty Plasmas

In this manuscript, we aim to derive a general dispersion relation applicable to a multi-component dusty plasma including massive negatively charged dust particles, both negative and positive ions, and electrons. Using the fluid treatment of plasma, we derive dispersion relations for dust ion-acoustic waves (DIAWs) and dust acoustic waves (DAWs) in self-gravitating dusty plasmas and collisional dusty plasmas by incorporating multiple species such as electrons, positive/negative ions, etc. Effects that arise in multicomponent dusty plasma due to negative ions are also discussed. The results obtained in this study are applicable in various space environments, such as cometary plasmas, astrophysical situations, planetary rings and interstellar medium.

Dust-Acoustic Shock Waves in a Self-Gravitating Opposite Polarity Dusty Plasmas With Trapped Ions

The basic characteristics of dust-acoustic (DA) shock waves (DASHWs) in self-gravitating dusty plasmas containing massive dust of opposite polarity, trapped ions, and Boltzmann electrons has been studied. The reductive perturbation technique has been employed to derive standard modified Burgers equation (mBE). The basic properties (viz., amplitude, width, and speed) of small but finite-amplitude DASHWs are significantly modified by the combined effects of positively and negatively charged dust component, self-gravitational force, and trapped ions. The implication of our investigation can be very effective for understanding and studying the nonlinear characteristics of the DA waves (DAWs) in laboratory and space dusty plasmas.

Analysis of radiative gravitational modes in magnetized dusty plasma with non-thermal ion distribution

The characteristics of radiative gravitational modes in non-thermal magnetized dusty plasma with charge fluctuation and the polarization force of dust particles are investigated. The electron species are assumed to be radiative and the ions are assumed to be non-thermal. A normal mode analysis is applied to derive the general dispersion relation for radiative magnetized self-gravitating dusty plasma. Modified radiative condensation and self-gravitational instability criteria for both perpendicular and parallel modes of propagation are obtained. Analytically, it is found that the presence of a non-thermal ion population significantly modified the usual radiative condensation instability criterion, and damped the growth rate of the radiative mode. The obtained analytical results are further discussed in the numerical result section. We investigate the fact that the non-thermal ion population acts as a stabilizing source for radiative condensation instability in magnetized self-gravitating dusty plasma fluid, including the dust polarization force and charge fluctuation. The thermal conductivity with non-thermal ion distribution quickly moves the system towards stability. The implications of the results in the region of the interstellar medium (ISM) are discussed.

Dust oscillons with finite OAM and dust self-gravity effects

Dust oscillons, or dust waves carrying distinct states of orbital angular momentum (OAM), are studied in a self-gravitating unmagnetized dusty plasma, whose constituents are the inertialess electrons and ions with negatively charged mobile massive dust grains. Starting from the linearized fluid equations, an evolution equation in terms of dust density perturbation is derived. By using the beam type solution, the wave is assumed to propagate around the beam axis with slowly varying amplitude proportional to exp(ikz). It leads to a paraxial equation of the wave that admits more generalized Laguerre–Gaussian beam solutions within paraxial limits. It is also shown that dust oscillons carry finite amount of energy flux and OAM density and are modified significantly by the azimuthal mode index and group velocity including the dust Jeans effects. Numerically, the dust Jeans frequency, azimuthal phase angle, as well as radial and azimuthal mode indices have strong dependence on the profiles of dust density perturbations. The present findings may prove useful to understand the dynamics of dust oscillons caused by the Brillouin backscattering of laser beams in a self-gravitating dusty plasma.

Dust-acoustic waves with finite OAM in a self-gravitating dusty plasma with superthermal energetic tails of electrons and ions

The kinetic instability of twisted dust-acoustic (DA) wave with distinct orbital angular momentum states is studied in an unmagnetized self-gravitating superthermal dusty plasma. For this purpose, the linearized Vlasov–Poisson equations are solved together by expressing the perturbed distribution function, electrostatic and gravitational potentials in terms of Laguerre–Gauss functions or solutions. A generalized plasma dielectric constant is derived and the existence conditions for the damping/growth rates are identified. The impact of streaming speed, dust self-gravitation, superthermality and twist parameters are numerically examined on the growth rate instability. It has been found that parametric variation significantly modifies the threshold conditions and associated growth rate instability of twisted DA waves. The relevance of the present results to interstellar dust clouds is illustrated, where massive dust grains follow a Maxwellian distribution in addition to superthermal electrons and ions.

Nucleus-acoustic waves: Excitation, propagation, and stability

The propagatory excitation dynamics of the collective nucleus-acoustic waves supported in a strongly coupled self-gravitating degenerate quantum dusty plasma (QDP) system, widely realizable as the constitutive matter for white dwarfs and other compact astro-objects, is semi-analytically studied. The spherically symmetric QDP is composed of strongly coupled non-degenerate heavy nuclei, weakly coupled degenerate light nuclei, and non-relativistically and ultra-relativistically degenerate lighter electrons. A standard normal spherical mode analysis is applied to derive a complex generalized dispersion relation. A numerical illustrative calculation is executed in the ultra-low frequency approximation to see the dependency of various sensible parameters on the instability evolution. It is seen that the relative nuclear charge-mass coupling parameter (β) acts as a destabilizing and stabilizing agents in the non-relativistic (NR) and ultra-relativistic (UR) limits, respectively. The ratio of the charge density of heavy-to-light nuclear species (μ) acts as a destabilizer (stabilizer) in the NR (UR) limits, to the instability. The quantum parameter (H′) interestingly acts as a stabilizing agency in both the NR-UR limits.

Propagation of symmetric and anti-symmetric surface waves in aself-gravitating magnetized dusty plasma layer with generalized (r, q) distribution

The dispersion properties of surface dust ion-acoustic waves in a self-gravitating magnetized dusty plasma layer with the (r, q) distribution are investigated. The result shows that the wave frequency of the symmetric mode in the plasma layer decreases with an increase in the wave number. It is also shown that the wave frequency of the symmetric mode decreases with an increase in the spectral index r. However, the wave frequency of the anti-symmetric mode increases with an increase in the wave number. It is also found that the anti-symmetric mode wave frequency increases with an increase in the spectral index r. In addition, it is found that the influence of the self-gravitation on the symmetric mode wave frequency decreases with increasing scaled Jeans frequency. Moreover, it is found that the wave frequency of the symmetric mode increases with an increase in the dust charge; however, the anti-symmetric mode shows opposite behavior.

The Hall-induced stability of gravitating fluids

We analyze the stability behavior of low-density partially ionized self-gravitating magnetized unbounded dusty plasma fluid in the presence of the Hall diffusion effects (HDEs) in the non-ideal magnetohydrodynamic (MHD) equilibrium framework. The effects of inhomogeneous self-gravity are methodically included in the basic model tapestry. Application of the Fourier plane-wave perturbative treatment decouples the structuration representative parameters into a linear generalized dispersion relation (sextic) in a judicious mean-fluid approximation. The dispersion analysis shows that the normal mode, termed as the gravito-magneto-acoustic (GMA) mode, is drastically modified due to the HDEs. This mode is highly dispersive, and driven unstable by the Hall current resulting from the symmetry-breaking of electrons and ions relative to the magnetic field. The mode feature, which is derived from a modified induction with the positive Hall, is against the ideal MHD. It is further demonstrated that the HDEs play stabilizing roles by supporting the cloud against gravitational collapse. Provided that the HDEs are concurrently switched off, the collapse occurs on the global spatial scale due to enhanced inward accretion of the gravitating dust constituents. It is seen explicitly that the enhanced dust-charge leads to stabilizing effects. Besides, the Hall-induced fluctuations, as propagatory wave modes, exhibit both normal and anomalous dispersions. The reliability checkup of the entailed results as diverse corollaries and special cases are illustratively discussed in the panoptic light of the earlier paradigmatic predictions available in the literature.

Nonlinear coupling of kinetic Alfven waves with acoustic waves in a self-gravitating dusty plasma with adiabatic trapping

In this paper, linear and nonlinear coupling of kinetic Alfven and acoustic waves has been studied in a dusty plasma in the presence of trapping and self-gravitation effects. In this regard, we have derived the linear dispersion relations for positively and negatively coupled dust kinetic Alfven-acoustic waves. Stability analysis of the coupled dust kinetic Alfven-acoustic wave has also been presented. The formation of solitary structures has been investigated following the Sagdeev potential approach by using the two-potential theory. Numerical results show that the solitary structures can be obtained only for sub-Alfvenic regimes in the scenario of space plasmas.

Low frequency modes and instability analysis in non-thermal dusty magnetoplasma considering dust charge fluctuation and polarization force

The effect of non-thermal ion population on self-gravitational instability of magnetized dusty plasma considering electrons are in Maxwell-Boltzmann distribution has been investigated. The dust dynamics is described including polarization force, thermal velocity, and charge fluctuation dust. The modified general dispersion relation has been derived including non-thermal ion population, polarization force, and dust charge fluctuation for self-gravitating dusty plasma system, using the normal mode analysis method. The obtained general dispersion relation is discussed in parallel and perpendicular modes of propagation. The population of non-thermal ion, polarization force and dust charge fluctuation affect the self-gravitational instability criteria in both the modes of propagation while the magnetic field affects the instability criterion only in perpendicular mode of propagation. The domains of instability has been discussed analytically to signify the importance of considered parameters. The stability of the self-gravitating dusty plasma system has been analyzed using Routh-Hurwitz stability criterion. Numerical calculations have been performed to analyze the effects of non-thermal ion population, polarization force, and dust charge fluctuation on the growth rate of self-gravitational instability. The results of the present work can be useful in self-gravitating dusty plasma found in space and the interstellar medium such as the interstellar molecular clouds where non-thermally distributed ions are the species of the plasma matter.

Influence of superthermal plasma particles on the Jeans instability in self-gravitating dusty plasmas with dust charge variations

A theoretical analysis of the dust acoustic waves in the self-gravitating dusty plasmas is presented within the consideration of the superthermal electrons, ions and dust charge variations. For this purpose, the current of electrons and ions to the dust surface is calculated, and then the dispersion relation for the dust acoustic waves is obtained. It is shown that by increasing the number of superthermal particles, the growth rate of the instability increases, the dust acoustic waves frequency decreases, and the instability region is extended to the smaller wavelengths. Moreover, it is found that the ratio of the electric force to the self-gravitational force is decreased in the presence of the superthermal particles, and dust charge variations.

Nonlinear propagation of ion-acoustic waves in self-gravitating dusty plasma consisting of non-isothermal two-temperature electrons

Nonlinear propagation of ion-acoustic waves in self-gravitating multicomponent dusty plasma consisting of positive ions, non-isothermal two-temperature electrons and negatively charged dust particles with fluctuating charges and drifting ions has been studied using the reductive perturbation method. It has been shown that nonlinear propagation of ion-acoustic waves in gravitating dusty plasma is described by an uncoupled third order partial differential equation which is a modified form of Korteweg–deVries equation, in contraries to the coupled nonlinear equations obtained by earlier authors. Quasi-soliton solution for the ion-acoustic solitary wave has been obtained from this uncoupled nonlinear equation. Effects of non-isothermal two-temperature electrons, gravity, dust charge fluctuation and drift motion of ions on the ion-acoustic solitary waves have been discussed.