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N. A. Chowdhury

Publications and source records attributed to N. A. Chowdhury.

At least 19 recordsLinked to original sources

Electrostatic shock structures in a magnetized plasma having non-thermal particles

A rigorous theoretical investigation has been made on the nonlinear propagation of dust-ion-acoustic shock waves in a multi-component magnetized pair-ion plasma having inertial warm positive and negative ions, inertialess non-thermal electrons and positrons, and static negatively charged massive dust grains. The Burgers' equation is derived by employing reductive perturbation method. The plasma model supports both positive and negative shock structures in the presence of static negatively charged massive dust grains. It is found that the steepness of both positive and negative shock profiles declines with the increase of ion kinematic viscosity without affecting the height, and the temperature of the electrons enhances the amplitude of the shock profile. It is also observed that the increase in oblique angle rises the height of the positive shock profile, and the height of the positive shock wave increases with the number density of positron. The application of the findings from present investigation are briefly discussed.

physics.plasm-ph↗

Ion-acoustic shock waves in a magnetized plasma featuring super-thermal distribution

A theoretical investigation has been made on the propagation of ion-acoustic (IA) shock waves (IASHWs) in a magnetized pair-ion plasma having inertial warm positive and negative ions, and inertialess super-thermal electrons and positrons. The well known Burgers' equation has been derived by employing the reductive perturbation method. The plasma model supports both positive and negative shock structures under consideration of super-thermal electrons and positrons. It is found that the oblique angle ($δ$) enhances the magnitude of the amplitude of both positive and negative shock profiles. It is also observed that the steepness of the shock profiles decreases with the kinematic viscosity of the ion, and the height of the shock profile increases (decreases) with the mass of the positive (negative) ion. The implications of the results have been briefly discussed for space and laboratory plasmas.

physics.plasm-ph↗

Dust-ion-acoustic shock waves in magnetized plasma having super-thermal electrons

The propagation of dust-ion-acoustic shock waves (DIASHWs) in a three-component magnetized plasma having inertialess super-thermal electrons, inertial warm positive ions and negative dust grains has been investigated. A Burgers' equation is derived by employing the reductive perturbation method. Under consideration of inertial warm positive ions and negative dust grains, both positive and negative shock structures are numerically observed in the presence of super-thermal electrons. The effects of oblique angle ($δ$), spectral index ($κ$), kinematic viscosity ($η$), number density and charge state of the plasma species on the formation of the DIASHWs are examined. It is found that the positive and negative shock wave potentials increase with the oblique angle. It is also observed that the magnitude of the amplitude of positive and negative shock waves is not affected by the variation of the kinematic viscosity of plasma species but the steepness of the positive and negative shock waves decreases with kinematic viscosity of plasma species. The implications of our findings in space and laboratory plasmas are briefly discussed.

physics.plasm-ph↗

Obliquely propagating ion-acoustic shock waves in degenerate quantum plasma

A theoretical investigation has been carried out on the propagation of nonlinear ion-acoustic shock waves (IASHWs) in a collsionless magnetized degenerate quantum plasma system composed of inertial non-relativistic positively charged light and heavy ions, inertialess ultra-relativistically degenerate electrons and positrons. The reductive perturbation method has been employed to drive the Burgers' equation. It has been observed that under consideration, our plasma model supports only positive potential shock structure. It is also found that the amplitude and steepness of the IASHWs have been significantly modified by the variation of ion kinematic viscosity, oblique angle, number density, and charge state of the plasma species. The results of our present investigation will be helpful for understanding the propagation of IASHWs in white dwarfs and neutron stars.

physics.plasm-ph↗

Magnetized ion-acoustic shock waves in degenerate quantum plasma

A theoretical investigation has been carried out to examine the ion-acoustic shock waves (IASHWs) in a magnetized degenerate quantum plasma system containing inertialess ultra-relativistically degenerate electrons, and inertial non-relativistic positively charged heavy and light ions. The Burgers' equation is derived by employing reductive perturbation method. It can be seen that under consideration of non-relativistic positively charged heavy and light ions, the plasma model supports only positive electrostatic shock structure. It is also observed that the charge state and number density of the non-relativistic heavy and light ions enhance the amplitude of IASHWs, and the steepness of the shock profile is decreased with ion kinematic viscosity ($η$). The findings of our present investigation will be helpful in understanding the nonlinear propagation of IASHWs in white dwarfs and neutron stars.

physics.plasm-ph↗

Modulational instability of dust-ion-acoustic waves and associated first and second-order rogue waves in super-thermal plasma

A proper theoretical research has been carried out to explore the modulational instability (MI) conditions of dust-ion-acoustic (DIA) waves (DIAWs) in a three-component dusty plasma system containing inertialess $κ$-distributed electrons, and inertial warm positive ions and negative dust grains. The novel nonlinear Schrödinger equation (NLSE) has been derived by employing the reductive perturbation method. The analysis under consideration demonstrates two types of modes, namely, fast and slow DIA modes. The dispersion and nonlinear properties of the plasma medium, as well as the MI conditions of DIAWs and the configuration of the energetic rogue waves (RWs) associated with DIAWs in the Modulationally unstable regime, have been rigorously changed by the plasma parameters, namely, charge, mass, temperature, and number density of the plasma species. The findings of our investigation will be useful in understanding the criteria for the formation of electrostatic RWs in both astrophysical environments (viz., Jupiter's magnetosphere, cometary tails, Earth's mesosphere, Saturn's rings, etc.) and laboratory experiments (viz., Q-machines and Coulomb-crystal).

physics.plasm-ph↗

Ion-acoustic shock waves in magnetized pair-ion plasma

A theoretical investigation associated with obliquely propagating ion-acoustic shock waves (IASHWs) in a three-component magnetized plasma having inertialess non-extensive electrons, inertial warm positive and negative ions has been performed. A Burgers equation is derived by employing the reductive perturbation method. Our plasma model supports both positive and negative shock structures under the consideration of non-extensive electrons. It is found that the positive and negative shock wave potentials increase with the oblique angle ($δ$) which arises due to the external magnetic field. It is also observed that the magnitude of the amplitude of positive and negative shock waves is not effected by the variation of the ion kinematic viscosity but the steepness of the positive and negative shock waves decreases with ion kinematic viscosity. The implications of our findings in space and laboratory plasmas are briefly discussed.

physics.plasm-ph↗

Modulational instability of dust-ion-acoustic waves in pair-ion plasma having non-thermal non-extensive electrons

The modulational instability (MI) criteria of dust-ion-acoustic (DIA) waves (DIAWs) have been investigated in a four-component pair-ion plasma having inertial pair-ions, inertialess non-thermal non-extensive electrons, and immobile negatively charged massive dust grains. A nonlinear Schrödinger equation (NLSE) is derived by using reductive perturbation method. The nonlinear and dispersive coefficients of the NLSE can predict the modulationally stable and unstable parametric regimes of DIAWs and associated first and second order DIA rogue waves (DIARWs). The MI growth rate and the configuration of the DIARWs are examined, and it is found that the MI growth rate increases (decreases) with increasing the number density of the negatively charged dust grains in the presence (absence) of the negative ions. It is also observed that the amplitude and width of the DIARWs increase (decrease) with the negative (positive) ion mass. The implications of the results to laboratory and space plasmas are briefly discussed.

physics.plasm-ph↗

Dust-ion-acoustic rogue waves in dusty plasma having super-thermal electrons

The standard nonlinear Schrödinger equation (NLSE) is one of the elegant equations to find the information about the modulational instability criteria of dust-ion-acoustic (DIA) waves (DIAWs) and associated DIA rogue waves (DIARWs) in a three-component dusty plasma medium having inertialess super-thermal kappa distributed electrons, and inertial warm positive ions and negative dust grains. It can be seen that under the consideration of inertial warm ions along with inertial negatively charged dust grains, the plasma system supports both fast and slow DIA modes. The charge state and number density of the ion and dust grain are responsible to change the instability conditions of the DIAWs and the configuration of DIARWs. These results are to be considered the cornerstone for explaining the real puzzles in space and laboratory dusty plasmas.

physics.plasm-ph↗

Ion-acoustic rogue waves in double pair plasma having non-extensive particles

The modulational instability (MI) of ion-acoustic (IA) waves (IAWs) and associated IA rogue waves (IARWs) in double pair plasma containing non-extensive electrons, iso-thermal positrons, negatively and positively charged ions have been governed by the standard nonlinear Schrödinger equation (NLSE). It has been figured out from the numerical study of NLSE that the plasma system holds modulationally stable (unstable) region in which the dispersive and nonlinear coefficients of the NLSE have the opposite (same) signs. It is also found that the fundamental features of IAWs (viz., MI criteria, amplitude and width of the IARWs, etc.) are rigorously organized by the plasma parameters such as mass, charge state, and number density of the plasma components. The existing outcomes of our present study should be helpful for understanding the nonlinear features of IAWs (viz., MI and IARWs) in both laboratory and space plasmas.

physics.plasm-ph↗

First and second-order dust-ion-acoustic rogue waves in non-thermal plasma

A nonlinear Schrödinger equation (NLSE) has been derived by employing reductive perturbation method for investigating the modulational instability of dust-ion-acoustic waves (DIAWs) in a four-component plasma having stationary negatively charged dust grains, inertial warm ions, and inertialess non-thermal electrons and positrons. It is observed that under consideration, the plasma system supports both modulationally stable and unstable domains, which are determined by the sign of the dispersive and nonlinear coefficients of NLSE, of the DIAWs. It is also found that the nonlinearity as well as the height and width of the first and second-order rogue waves increases with the non-thermality of electron and positron. The relevancy of our present investigation to the observations in space plasmas is pinpointed.

physics.plasm-ph↗

Electrostatic dust-acoustic envelope solitons in an electron depleted plasma

A standard nonlinear Schrödinger equation has been established by using the reductive perturbation method to investigate the propagation of electrostatic dust-acoustic waves, and their modulational instability as well as the formation of localized electrostatic envelope solitons in an electron depleted unmagnetized dusty plasma system comprising opposite polarity dust grains and super-thermal positive ions. The relevant physical plasma parameters (viz., charge, mass, number density of positive and negative dust grains, and super-thermality of the positive ions, etc.) have rigorous impact to recognize the stability conditions of dust-acoustic waves. The present study is useful for understanding the mechanism of the formation of dust-acoustic envelope solitons associated with dust-acoustic waves in the laboratory and space environments.

physics.plasm-ph↗

Modulational instability of dust-ion-acoustic waves and associated envelope solitons in a non-thermal plasma

A theoretical investigation has been made to understand the mechanism of the formation of both bright and dark envelope soltions associated with dust-ion-acoustic waves (DIAWs) propagating in an unmagnetized three component dusty plasma medium having inertial warm positive ions and negative dust grains, and inertialess non-thermal Cairns' distributed electrons. A nonlinear Schrödinger equation (NLSE) is derived by employing reductive perturbation method. The effects of plasma parameters, viz., $γ_2$ (the ratio of the positive ion temperature to electron temperature times the charge state of ion) and $ν$ (the ratio of the charge state of negative dust grain to positive ion) on the modulational instability of DIAW which is governed by NLSE, are extensively studied. It is found that increasing the value of the ion (electron) temperature reduces (enhances) the critical wave number ($k_c$). The results of our present theoretical work may be used to interpret the nonlinear electrostatic structures which can exist in many astrophysical environments and laboratory plasmas.

physics.plasm-ph↗

Dust-acoustic envelope solitons in an electron depleted plasma

A theoretical investigation of the modulational instability (MI) of dust-acoustic waves (DAWs) by deriving a nonlinear Schrödinger equation in an electron depleted opposite polarity dusty plasma system containing non-extensive positive ions has been presented. The conditions for MI of DAWs and formation of envelope solitons have been investigated. The sub-extensivity and super-extensivity of positive ions are seen to change the stable and unstable parametric regimes of DAWs. The addition of dust grains causes to change the width of both bright and dark envelope solitons. The findings of this study may be helpful to understand the nonlinear features of DAWs in Martian atmosphere, cometary tail, solar system, and in laboratory experiments, etc.

physics.plasm-ph↗

Modulational instability of ion-acoustic waves and associated envelope solitons in a multi-component plasma

A generalized plasma model having warm ions, iso-thermal electrons, super-thermal electrons and positrons is considered to theoretically investigate the modulational instability (MI) of ion-acoustic waves (IAWs). A standard nonlinear Schrödinger equation is derived by applying reductive perturbation method to study the MI of IAWs. It is observed that the MI criteria of the IAWs are significantly modified by various plasma parameters. The present results should be useful in understanding the conditions for MI of IAWs which are relevant to both space and laboratory plasma system.

physics.plasm-ph↗

Dust-acoustic rogue waves in non-thermal plasmas

The nonlinear propagation of dust-acoustic (DA) waves (DAWs) and associated DA rogue waves (DARWs), which are governed by the nonlinear Schrödinger equation, is theoretically investigated in a four component plasma medium containing inertial warm negatively charged dust grains and inertialess non-thermal distributed electrons as well as iso-thermal positrons and ions. The modulationally stable and unstable parametric regimes of DAWs are numerically studied for the plasma parameters. Furthermore, the effects of temperature ratios of ion-to-electron and ion-to-positron, and the number density of ion and dust grains on the DARWs are investigated. It is observed that the physical parameters play a very crucial role in the formation of DARWs. These results may be useful in understanding the electrostatic excitations in dusty plasmas in space and laboratory situations.

physics.plasm-ph↗

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↗

Modulational instability of dust-ion-acoustic mode and associated rogue waves in a non-extensive plasma medium

The modulational instability of dust-ion-acoustic (DIA) mode and associated rogue waves in a three component dusty plasma system (containing inertial warm ion and negatively charged dust fluids along with inertialess $q$-distributed electrons) has been theoretically investigated. A nonlinear Schrödinger equation (NLSE) has been derived by employing the reductive perturbation method. It is observed that the dusty plasma system under consideration supports the fast and slow DIA modes, and that the dispersion and nonlinear coefficients of the NLSE determine the parametric regimes not only for the modulationally stable and unstable fast DIA mode, but also for the formation of the DIA rogue waves. The parametric regimes for the modulational instability of the fast DIA mode, and the criterion for the formation of the DIA rogue waves have been found to be significantly modified by the effects of the relevant plasma parameters, particularly, mass and charge state of ion and dust species, number density of the plasma species, and non-extensive parameter $q$, etc. It is found that the modulationally stable parametric regime decreases (increases) with the increase in the value of positive (negative) $q$. The numerical analysis has also shown that the nonlinearity as well as the amplitude and width of the rogue waves increases (decreases) with the mass of positive ion (negative dust grains) while decreases (increases) with the charge state of the positive ion (negative dust). The applications of our present work in space (viz., Earth ionosphere, magnetosphere, molecular clouds, interstellar medium, cometary tails, and planetary rings, etc.) and laboratory plasmas have been pinpointed.

physics.plasm-ph↗