arXiv subjects

A. Mannan

Publications and source records attributed to A. Mannan.

At least 37 records · Page 2Linked to original sources

arXiv2019

Ion-acoustic rogue waves in a multi-component plasma medium

The nonlinear propagation of ion-acoustic (IA) waves (IAWs) in a four component plasma medium (FCPM) containing inertial warm positive ions, and inertialess iso-thermal cold electrons as well as non-extensive ($q$-distributed) hot electrons and positrons is theoretically investigated. A nonlinear Schrödinger equation (NLSE) is derived by using the reductive perturbation method, and it is observed that the FCPM under consideration supports both modulationally stable and unstable parametric regimes which are determined by the sign of the dispersive and nonlinear coefficients of NLSE. The numerical analysis has shown that the maximum value of the growth rate decreases with the increase in $q$ ($q>1$), and the modulationally unstable parametric regime allows to generate highly energetic IA rogue waves (IARWs), and the amplitude and width of the IARWs increase with an increase in the value of hot electron number density while decrease with an increase in the value of cold electron number density. The applications of our investigation in understanding the basic features of nonlinear electrostatic perturbations in many space plasma environments and laboratory devices are briefly discussed.

physics.plasm-ph↗

arXiv2019

Dust-ion-acoustic rogue waves in presence of non-extensive non-thermal electrons

Dust-ion-acoustic (DIA) rogue waves (DIARWs) are investigated in a three components dusty plasma system containing inertialess electrons featuring non-thermal non-extensive distribution as well as inertial warm ions and negative dust grains. A nonlinear Schrödinger equation (NLSE), which governs the conditions of the modulational instability (MI) of DIA waves (DIAWs), is obtained by using the reductive perturbation method. It has been observed from the numerical analysis of NLSE that the plasma system supports both modulationally stable domain in which dispersive and nonlinear coefficients of the NLSE have same sign and unstable domain in which dispersive and nonlinear coefficients of the NLSE have opposite sign, and also supports the DIARWs only in the unstable domain. It is also observed that the basic features (viz. stability of the DIAWs, MI, growth rate, amplitude, and width of the DIARWs, etc.) are significantly modified by the related plasma parameters (viz. dust charge state, number density of electron and ion, non-extensive parameter q, and non-thermal parameter $α$, etc.). The present study is useful for understanding the mechanism of the formation of DIARWs in the laboratory and space environments where inertialess mixed distributed electrons can exist with inertial ions and dust grains.

physics.plasm-ph↗

arXiv2019

Dust-acoustic rogue waves in an electron-positron-ion-dust plasma medium

A precise theoretical investigation has been made on dust-acoustic (DA) waves (DAWs) in a four components dusty plasma medium having inertial warm adiabatic dust grains and inertialess $q$-distributed electrons as well as isothermal ions and positrons. The nonlinear and dispersive parameters of the nonlinear Schrödinger equation (NLSE), which develops by using reductive perturbations technique, have been used to recognize the stable and unstable parametric regions of the DAWs as well as associated DA rogue waves (DARWs) in the unstable parametric regime of the DAWs. The effects of the light positrons and massive dust grains in determining the amplitude and width of the DARWs associated with DAWs are examined. The findings of our present investigation may be useful for understanding different nonlinear electrostatic phenomena in both space and laboratory plasmas.

physics.plasm-ph↗

arXiv2019

Electrostatic dust-acoustic rogue waves in an electron depleted dusty plasma

The formation of the gigantic dust-acoustic rouge waves (DARWs) in an electron depleted unmagnetized opposite polarity dusty plasma system is theoretically observed for the first time. The nonlinear Schrödinger equation (derived by utilizing the reductive perturbation method) has been analytically as well as numerically analyzed to identify the basic features (viz., height, thickness, and modulational instability, etc.) of DARWs. The results obtained form this investigation should be useful in understanding the basic properties of these rouge waves which can predict to be formed in electron depleted unmagnetized opposite polarity dusty plasma systems like mesosphere, F-rings of Saturn, and cometary atmosphere, etc.

physics.plasm-ph↗

arXiv2019

Dust-acoustic rogue waves in an electron depleted plasma

A rigorous theoretical investigation is made to study the characteristics of dust-acoustic (DA) waves (DAWs) in an electron depleted unmagnetized opposite polarity dusty plasma system that contains super-thermal ($κ$-distributed) ions, mobile positively and negatively charged dust grains for the first time. The reductive perturbation method is employed to obtain the NLSE to explore the modulational instability (MI) conditions for DAWs as well as the formation and characteristics of gigantic rogue waves. The nonlinear and dispersion properties of the dusty plasma medium are the prime reasons behind the formation of rogue waves. The height and thickness of the DARWs associated with DAWs as well as the MI conditions of DAWs are numerically analyzed by changing different dusty plasma parameters, such as dust charges, dust and ion number densities, and ion-temperature, etc. The implications of the results for various space dusty plasma systems (viz., mesosphere, F-rings of Saturn, and cometary atmosphere, etc.) as well as laboratory dusty plasma produced by laser-matter interaction are briefly mentioned.

physics.plasm-ph↗

arXiv2019

Ion-acoustic rogue waves in multi-ion plasmas

The basic properties of nonlinear ion-acoustic (IA) waves (IAWs), particularly finite amplitude IA rogue waves (IARWs) in a plasma medium (containing pair ions, iso-thermal positrons and non-thermal electrons) are theoretically investigated by deriving the nonlinear Schrödinger equation (NLSE). The criteria for the modulational instability of IAWs, and the basic features of finite amplitude IARWs are identified. The modulationally stable and unstable regions are determined by the sign of the ratio of the dispersive coefficient to the nonlinear coefficient of NLSE. The latter is analyzed to obtain the region for the existence of the IARWs, which corresponds to the unstable region. The shape of the profile of the rogue waves depends on the non-thermal parameter $α$ and the ratio of electron temperature to positron temperature. It is found that the increase in the value of the non-thermal parameter enhances both the amplitude and width of IARWs, and that the enhancement of positron (electron) temperature reduces (enhances) the amplitude and width of IARWs. It is worth to mention that our present investigation may be useful for understanding the salient features of IARWs in space (viz., upper region of Titan's atmosphere, cometary comae, and Earth's ionosphere, etc.) and laboratory (viz., plasma processing reactor and neutral beam sources, etc.) plasmas.

physics.plasm-ph↗

arXiv2019

Envelope solitons in double pair plasmas

A double pair plasma system containing cold inertial positive and negative ions, and inertialess super-thermal electrons and positrons is considered. The standard nonlinear Schrödinger equation is derived by using the reductive perturbation method to investigate the nonlinear dynamics of the ion-acoustic waves (IAWs) as well as their modulation instability. It is observed that the ion-acoustic dark (bright) envelope solitons are formed for modulationally stable (unstable) plasma region, and that the presence of highly dense super-thermal electrons and positrons enhances (reduces) this unstable (stable) region. It is also found that the effect of super-thermality of electron or positron species causes to increase the nonlinearity, and to fasten the formation of the bright envelope solitons. These results are applicable to both space and laboratory plasma systems for understanding the propagation of localized electrostatic disturbances.

physics.plasm-ph↗

arXiv2019

Dust-acoustic envelope solitons in super-thermal plasmas

The modulational instability (MI) of the dust-acoustic waves (DAWs) in an electron-positron-ion-dust plasma (containing super-thermal electrons, positrons and ions along with negatively charged adiabatic dust grains) is investigated by the analysis of the nonlinear Schrödinger equation (NLSE). To derive the NLSE, the reductive perturbation method has been employed. Two different parametric regions for stable and unstable DAWs are observed. The presence of super-thermal electrons, positrons and ions significantly modifies both the stable and unstable regions. The critical wave number $k_c$ (at which modulational instability sets in) depends on the super-thermal electron, positron, and ion, and adiabatic dust concentrations.

physics.plasm-ph↗

arXiv2018

Dust-acoustic rogue waves in four component plasmas

A theoretical investigation has been made on modulational instability (MI) and dust-acoustic (DA) rogue waves (DARWs) in a four dusty plasma medium containing inertial negatively charged massive heavy (light) cold (hot) dust grains as well as super-thermal electrons and non-thermal ions. The reductive perturbation method is used to derive the nonlinear Schrödinger equation, and two types of modes, namely fast and slow DA modes, have been observed. The conditions for the MI and the formation of associated DARWs are found to be significantly modified by the effects of non-thermality of ions ($α$), super-thermality of electrons ($κ$), density-ratio of non-thermal ion to cold dust ($μ_i$), and mass-ratio of cold dust to hot dust ($σ$), etc. The implications of our current investigation in space and laboratory plasmas are briefly discussed.

physics.plasm-ph↗

arXiv2018

Rogue waves in multi-pair plasma medium

The nonlinear propagation of ion-acoustic (IA) waves (IAWs), which are governed by the nonlinear Schrödinger equation (NLSE), in multi-pair plasmas (MPPs) containing adiabatic positive and negative ion fluids as well as non-extensive ($q$-distributed) electrons and positrons, is theoretically investigated. It is observed that the MPP under consideration supports two types of modes (namely, fast and slow IA modes), and the modulationally stable and unstable parametric regimes for the fast and slow IA modes are determined by the sign of the ratio of the dispersive coefficient to the nonlinear one. It is also found that the modulationally unstable regime generates highly energetic IA rogue waves (IARWs), and the amplitude as well as the width of the IARWs decrease with increase in the value of $q$ (for both $q>0$ and $q<0$ limits). These new striking features of the IARWs are found to be applicable in the space [viz. D-region ($\rm H^+, O_2^-$) and F-region ($\rm H^+, H^-$) of the Earth's ionosphere] and laboratory MPPs [viz. fullerene ($\rm C^+, C^-$)].

physics.plasm-ph↗

arXiv2018

Electrostatic rogue waves in double pair plasmas

A nonlinear Schrödinger equation is derived to investigate the modulational instability (MI) of ion-acoustic (IA) waves (IAWs) in a double pair plasma system containing adiabatic positive and negative ion fluids along with super-thermal electrons and positrons. The analytical analysis predicts two types of modes, viz. fast ($ω_f$) and slow ($ω_s$) IA modes. The possible stable and unstable parametric regions for the IAWs in presence of external perturbation can be observed for both $ω_f$ and $ω_s$. The number density of the negative ions and positrons play a vital role in generating the IA rogue waves (IARWs) in the modulationally unstable region. The applications of our present work in astrophysical environments [viz. D-region ($\rm H^+, O_2^-$) and F-region ($\rm H^+, H^-$) of the Earth's ionosphere] as well as in laboratory plasmas [viz. pair-ion Fullerene ($\rm C^+, C^-$)] are pinpointed.

physics.plasm-ph↗

arXiv2018

Generation of rogue waves in space dusty plasmas

The basic features of dust-acoustic (DA) waves (DAWs) in four component dusty plasma system (containing inertial cold and hot dust grains, inertialess non-extensive ions and electrons) have been theoretically investigated by deriving the nonlinear Schrödinger equation. The analytic analysis under consideration demonstrates two types of modes, namely, fast and slow DA modes. The unstable domain for the fast DA mode, which can be recognized by the critical wave number ($k_c$), gives rise to the DA rogue waves (DARWs). It is observed that the amplitude and width of the DARWs are significantly modified by various plasma parameters. The present results should be useful in understanding the conditions for modulational instability of DAWs and generation of DARWs in space dusty plasma systems like Saturn F-rings.

physics.plasm-ph↗

arXiv2018

Modulational instability, rogue waves, and envelope solitons in opposite polarity dusty plasmas

Dust-acoustic (DA) waves (DAWs) and their modulational instability (MI) have been investigated theoretically in a plasma system consisting of inertial opposite polarity (positively and negatively) warm adiabatic charged dust particles as well as inertialess non-extensive $q$-distributed electrons and non-thermal ions. A nonlinear Schrödinger (NLS) equation is derived by using the reductive perturbation method. It has been observed from the analysis of NLS equaion that the modulationally stable solitary DAWs give rise to the existence of dark envelope solitons, and that the modulationally unstable solitary DAWs give rise to the existence of bright envelope solitons or rogue structures. It is also observed for the fast mode of DAWs that the basic features (viz. stability of the DAWs, MI growth rate, amplitude and width of the DA rogue waves, etc.) are significantly modified by the related plasma parameters (viz. dust masses, dust charge state, non-extensive parameter $q$, and non-thermal parameter $α$). The results of our present investigation might be useful for understanding different nonlinear electrostatic phenomena in both space (viz. ionosphere and mesosphere) and laboratory plasmas (viz. high intensity laser irradiation and hot cathode discharge).

physics.plasm-ph↗

arXiv2018

Self-gravitating envelope solitons in a degenerate quantum plasma system

The existence and the basic features of ion-acoustic (IA) envelope solitons in a self-gravitating degenerate quantum plasma system (SG-DQPS), containing inertial non-relativistically degenerate light and heavy ion species as well as inertialess non-relativistically degenerate positron and electron species, have been theoretically investigated by deriving the nonlinear Schrödinger (NLS) equation. The NLS equation, which governs the dynamics of the IA waves, has disclosed the modulationally stable and unstable regions for the IA waves. The unstable region allows to generate bright envelope solitons which are modulationaly stable. It is found that the stability and the growth rate dependent on the plasma parameters (like, mass and number density of the plasma species). The implications of our results in astronomical compact object (viz. white dwarfs, neutron stars, and black holes, etc.) are briefly discussed.

physics.plasm-ph↗

arXiv2018

Self-gravitating envelope solitons in astrophysical compact objects

The propagation of ion-acoustic waves (IAWs) in a collisionless unmagnetized self-gravitating degenerate quantum plasma system (SG-DQPS) has been studied theoretically for the first time. A nonlinear Schrödinger equation is derived by using the reductive perturbation method to study the nonlinear dynamics of the IAWs in the SG-DQPS. It is found that for $k_c > k$ ($k_c < k$) (where $k_c$ is critical value of the propagation constant $k$ which determines the stable and unstable region of IAWs) the IAWs are modulationally unstable (stable), and that $k_c$ depends only on the ratio of the electron number density to light ion number density. It is also observed that the self-gravitating bright envelope solitons are modulationally stable. The results obtained from our present investigation are useful for understanding the nonlinear propagation of the IAWs in astrophysical compact objects like white dwarfs and neutron stars.

physics.plasm-ph↗

arXiv2018

Modulated dust-acoustic wave packets in an opposite polarity dusty plasma system

The nonlinear propagation of the dust-acoustic bright and dark envelope solitons in an opposite polarity dusty plasma system (composed of non-extensive $q$-distributed electrons, isothermal ions, and positively as well as negatively charged warm dust) have been theoretically investigated. The reductive perturbation method (which is valid for a small, but finite amplitude limit) is employed to derive the nonlinear Schrödinger equation. Two types of modes (namely, fast and slow dust-acoustic (DA) modes) have been observed. The conditions for the modulational instability (MI) and its growth rate in the unstable regime of the DA waves are significantly modified by the effects of non-extensive electrons, dust mass, temperatures of different plasma species, etc. The implications of the obtained results from our current investigation in space (viz. Jupiters magnetosphere, upper mesosphere, and comets tails) and laboratory (e.g. direct current and radio-frequency discharges, plasma processing reactors, fusion plasma devices, and solid-fuel combustion products, etc.) dusty plasmas are briefly discussed.

physics.plasm-ph↗

arXiv2017

Dust-acoustic rogue waves in an opposite polarity dusty plasma featuring non-extensive statistics

Modulational instability (MI) of dust acoustic waves (DAWs), which propagates in an opposite polarity dusty plasma system, containing inertial warm negatively and positively charged dust particles as well as non-extensive q-distributed elec- trons and ions, has been theoretically investigated. The nonlinear Schrodinger (NLS) equation is derived by employing the reductive perturbation method. The NLS equation leads to the MI of DAWs as well as to the formation of DAW rogue waves (DARWs), which are formed due to the effects of nonlinearity in the propagation of DAWs. Both stable and unstable regions are revealed from the analysis of the NLS equation. It is observed that the basic features of the DAWs (viz. stability of the wave profile, MI growth rate, amplitude, and width of DARWs) are significantly modified by the various plasma parameters such as non-extensive parameter, electron number density, and electron temperature. The existence of the non-extensive electron/ion distribution creates an influence on the MI of the waves. It is observed that non-extensive distributed ions have more effect on the MI of the DAWs than electrons.

physics.plasm-ph↗

arXiv2017

Modulational Instability and Generation of Envelope Solitons in Four Component Space Plasmas

A four component space plasma system (consisting of immobile positive ions, inertial cold positrons as well as hot electrons and positrons following Cairns' nonthermal distribution function is considered. The nonlinear propagation of the positron-acoustic (PA) waves, in which the inertia (restoring force) is provided by the cold positron species (nonthermal pressure of both hot electron and positron species) has been theoretically investigated by deriving the nonlinear Schrödinger (NLS) equation. It is found from the numerical analysis of this NLS equation that the space plasma system under consideration supports the existence of both dark and bright envelope solitons associated with PA waves, and that the dark (bright) envelope solitons are modulationally stable (unstable). It is also observed that the basic properties (viz. stable regime and unstable regime with growth rate) of the PA envelope solitions are significantly modified by related plasma parameters (viz. number densities and temperature of plasma species), which correspond to different realistic space plasma situations.

physics.plasm-ph↗