P.K. Karmakar

Tezpur University · Department of Physics

The pulsational mode of gravitational collapse (PMGC) originating from the combined gravito-electrostatic interaction in complex dust molecular clouds (DMCs) is a canonical mechanism leading to the onset of astronomical structure formation dynamics. A generalized semi-analytic model is formulated to explore the effects of the Eddington-inspired Bor...

In the post-Newtonian era, the Eddington-inspired Born-Infeld (EiBI) theory, considered as an improved modification of the Einsteinian general relativity formalism in the weak field regime (non-relativistic), has enabled us to study the dynamics of dense astroobjects in light of the modified gravitational effects. This EiBI theory imparts a new sha...

The sheath plasma resonance (SPR) in an inverted fireball (IFB) system is semi-analytically investigated using a generalized hydrodynamic isothermal model formalism. It incorporates the constitutive ionic fluid viscosity, inter-species collisions, and geometric curvature effects. The SPR stability is studied for an anodic (hollow, meshed) IFB for t...

A partially ionized dust molecular cloud (DMC) with both neutral and charged dust grains along with plasma components modifies the traditional Jeans instability. This leads to a novel Jeans-like hybrid mode called the pulsational mode of gravitational collapse (PMGC). A semi-analytic DMC model is formulated to explore the effects of dust-polarizati...

The stability dynamics, of the gravito-electrostatically driven pulsational mode of gravitational collapse (PMGC) excitable in spherically symmetric dust molecular clouds (DMCs), is systematically theorized. It actively incorporates the interplay of dust viscosity, dust charge fluctuation dynamics, and negionic (negative ionic) effects. We take the...

The torsional Alfvén wave is highly regarded as the carrier of the energy from the photosphere to the corona in the solar atmosphere. This paper presents a comprehensive linear analysis of the wave behavior and energy transfer within an open, twisted, divergent magnetic flux tube configuration, considering the impact of wave guide structure on the...

The Eddington-inspired Born-Infeld (EiBI) gravitational theory is a leading post-Newtonian gravitational model equivalent to Einstein’s general relativity in vacuum. In the non-relativistic Newtonian limit, the EiBI gravitational theory modifies the Poisson equation governing the gravitational force field sourced in cosmic matter. This theory has b...

The nonlinear Jeans instability dynamics in viscoelastic astrofluids within the Eddington-inspired Born-Infeld (EiBI) gravitational framework excitable in star-forming interstellar cloud fluids is semi-analytically investigated. Application of multiple scaling techniques here results in a unique form of the Korteweg-de Vries (KdV) equation moderate...

The stability dynamics of the pulsational mode of gravitational collapse (PMGC), excitable in athermal (nonthermal) spherical complex dust molecular clouds (DMCs) in the presence of active role of negative ions, is semi-analytically investigated. The adopted partially ionized DMC model consists of five constitutive plasma species, well-coupled via...

The sheath plasma instabilities (SPIs) excitable in unstable inverted fireballs (IFBs) is theoretically analyzed. It applies a bifluidic (electronic and ionic) plasma model approach. The different quasilinear parametric fluctuations are procedurally decoupled in the form of an ordinary differential equation of order-2 (ODE(2)) electrostatic potenti...

The gravito-electrostatic sheath (GES) model, exploring the solar wind plasma (SWP) origin from the solar interior plasma (SIP) via the solar surface boundary (SSB), is revaluated by including realistic negative ionic species. A constructive numerical analysis of the structuring equations shows that the SIP volume shrinks with an increase in the ne...

In the post-Newtonian era, the Eddington-inspired Born-Infeld (EiBI) theory, considered as an improved modification of the Einsteinian general relativity formalism in the weak field regime (non-relativistic), has enabled us to study the dynamics of dense astroobjects in light of the modified gravitational effects. This EiBI theory imparts a new sha...

The pulsational mode of gravitational collapse (PMGC) originating from the combined gravito-electrostatic interaction in complex dust molecular clouds (DMCs) is a canonical mechanisms leading to the onset of astronomical structure formation dynamics. A semi-analytic generalized model is formulated to examine the collective effects of polarization f...

Within the confines of a two-fluid quantum magnetohydrodynamic model, the investigation of magnetoacoustic shock and solitary waves is conducted in an electron-ion magnetoplasma that considers electrons of spin 1/2. When the plasma system is nonlinearly investigated using the reductive perturbation approach, the Korteweg de Vries-Burgers (KdVB) equ...

We systematically theorise a model formalism to investigate the linear pulsational mode dynamics excitable in self-gravitating dust molecular clouds (DMCs) in the framework of the Eddington-inspired Born-Infeld (EiBI) gravity. The adopted spherical DMC consists of thermalized lighter (non-inertial) electrons and ions, both treated analogously as...

The Eddington-inspired Born-Infeld (EiBI) theory of gravity is an emerging post-Newtonian theory equivalent to Einstein's General Relativity (GTR) in vacuum. It introduces modifications to the self-gravitating potential of an astrofluid in dense matter environments. In the non-relativistic Newtonian limit, it introduces an additional correction ter...

A quantum hydrodynamic model formalism is semi-analytically offered to explore the propagatory and dispersive nature of heavy nucleus-acoustic waves (NAWs) in the completely degenerate (CD) oxygen-neon (ONe) and CO white dwarf (WD) cores. It includes their surrounding nearly degenerate (ND) transition regions. It has classical light nuclear species...

The principal goal of this structured presentation is to highpoint the recent stability behavioral dynamics of the nucleus-acoustic wave (NAW) modes in astrophysical gyrogravitating degenerate quantum plasmas mimicking the white dwarf family. A numerical dispersion platform depics intriguingly that the Coriolis rotation boosting suppresses the NAW...

The nonlinear evolutionary dynamics of the hybrid Jeans-Buneman instability (JBI) in charge-fluctuating viscous dust molecular clouds (DMCs) of infinite extension is semi-analytically studied. The cloud macroscopic state is initially considered to be in a quasi-hydrostatic homogeneous equilibrium configuration, modeled in a classical non-relativist...

A recently reported Gravito-Electrostatic Sheath (GES) model is procedurally applied to study the turbumagnetoactive helioseismic oscillation features in the entire bi-fluidic solar plasma system (DAS & KARMAKAR, JOAA, 2022). The bounded Solar Interior Plasma (SIP, internally self-gravitating), and the unbounded Solar Wind Plasma (SWP, externally p...

We employ a quantum hydrodynamic model to investigate the cylindrical acoustic waves excitable in a gyromagnetoactive self-gravitating viscous cylinder comprised of two-component (electron–ion) plasma. The electronic equation of state incorporates the effect of temperature degeneracy. It reveals an expression for the generalized pressure capable of...

We theoretically study the nonlinear pulsational mode dynamics in strongly correlated (viscoelastic) self-gravitating complex charge-fluctuating dust molecular clouds (DMCs) on the astrophysical spatiotemporal scales. A nonlinear normal mode (local) analysis results in a unique pair of extended Kortweg de-Vries-Burgers (KdV-B) equations on the conj...

A theoretic hydrodynamic model is constructed to analyze the propagatory nucleus-acoustic wave (NAW) modes, excitable in the completely degenerate core and in its nearly degenerate ambience of the ONeMg white dwarfs (WDs). We consider a three-component plasma system consisting of tiny quantum electrons, light nuclear species (LNS), and heavy nuclea...

Theoretical research has been done on inhomogeneous multi-component magnetized plasmas that contain inertial ions, nonthermal electrons, and Boltzmannian positrons. Variable coefficients Za-kharov Kuznetsov (VZK) equation have been derived. The solitary wave structures are dependent on the inhomogeneity effects of ion density n i0 (x), velocity, u...

We present a theoretic model formalism perspectively developed to explore the stability behavioral dynamics of the nucleus-acoustic waves (NAWs) in diversified gyrogravitating degenerate quantum astroplasmas. It evolves under the joint influence of the Bohm potential, Coriolis rotation, electrostatic confinement pressure (ECP), viscoelasticity, etc...

The stability of steady plasma fireball sheath (PFS) fluctuations in a bifluidic plasma model approach is explored by applying the standard method of multi-order nonlinear normal mode meta-analysis in a spherical geometry. We consider the fourth-order nonlinear local fluctuations of the relevant plasma parameters evolving across the PFS region for...

A theoretic model formalism is developed to investigate the nonlinear gravito-electrostatically coupled streaming instability modes excitable in viscoelastic quantum dusty plasmas. It consists of weakly correlated light electrons, ions; and strongly correlated heavy dust grains. We treat the inertialess electrons as a degenerate quantum fluid, iner...

Shock and solitary waves in plasmas are the main focus of many current studies of localized disturbances in both laboratory and astrophysical plasmas. Here, the linear and the nonlinear properties evolving in three dimensions quantum magnetized spin-1/2 plasma formed of spin up (↑) and spin down (↓), nonrelativistic degenerate inertialess electrons...

The gravitoelectrostatic sheath (GES) model for exploring the surface emission mechanism of the solar wind plasma (SWP), transformed from the solar interior plasma (SIP) via the solar surface boundary (SSB), has recently been reformulated in different conditions. It considers the realistic plasma key factors previously remaining unaddressed. This c...

Motivated by the recent Magnetospheric Multiscale (MMS) observations of oblique electron acoustic waves, we addressed the generation mechanism of the observed waves by utilizing the reductive perturbation technique. A nonlinear Zakharov-Kuznetsov (ZK) equation is derived for a collisionless, magnetised plasma composed of cool inertial background el...

The gravito-electrostatic sheath (GES) model, originally formulated to see the surface origin of solar wind plasma (SWP) originating from the solar interior plasma (SIP) through the quasi-linear coupling non-rigid solar surface boundary (SSB), is revisited. The model genesis is the application of laboratory plasma-wall coupling and cross-border eff...

A semi-analytic admixed model formalism to study the stability effects of the inner crust regions against the local collective perturbations in non-rotating neutron stars is proposed. It consists of the viscoelastic heavy neutron-rich nuclei, superfluid neutrons, and degenerate quantum electrons. A normal spherical mode analysis yields a generalize...

The omnipresence of dust particulates in space and astrophysical plasmas has been attracting numerous researchers to study the collective excitation and propagation dynamics of different eigen-mode structures in diversifed astrocosmic circumstances for years. It includes planetary rings, interplanetary space, cometary tails, asteroid zones, planeta...

Notably, solitary waves that emerge from the nonlinear properties of plasmas are the main focus of many current studies of localized disturbances in both laboratory and astrophysical plasmas. By applying the reductive perturbation method, we derive the nonlinear homogeneous quantum Zakharov–Kuznetsov (QZK) equation in three-component collisionless...

The omnipresence of dust particulates in space and astrophysical plasmas has been attracting numerous researchers to study the collective excitation and propagation dynamics of different eigenmode structures in diversified astrocosmic circumstances for years. It includes planetary rings, interplanetary space, cometary tails, asteroid zones, planeta...

Evolutionary existence of plasma fireballs is a generic phenomenon realizable in diversified physical plasma-dominated circumstances starting from laboratory to astrocosmic scales of space and time. A fair understanding of such fireballs and associated instabilities is really needed to enrich astroplasmic communities from various perspectives of ap...

The acoustic modal instability excitable in a relativistic gyromagnetoactive quantum plasma model is methodologically investigated. The proposed spherical model consists of fully degenerate relativistic electronic species, governed by an appropriate barotropic equation of state sourced in the gyrokinetic water-bag distribution. The tiny degenerate...

Award of Reviewer Recognition (Taylor & Francis)

Award of Reviewer Certificate

Award by Physica Scripta (ioP)

Certificate for excellence in review

A model formalism for the small-scale radial fluctuations excitable in the athermal (non-thermal) solar plasma system on the basis of the non-extensive gravito-electrostatic sheath (GES) model fabric is reported. A unique speciality here is that it intercouples the solar interior plasma (SIP) and the solar wind plasma (SWP) gravito-electrostaticall...

A laboratory plasma-wall interaction-based astrophysical gravito-electrostatic sheath (GES) model is methodologically applied to study the dynamic stability of the magnetoactive bi-fluidic solar plasma system in the presence of turbulence effect. The spherically symmetric GES-model formalism couples the solar interior plasma (SIP, internally self-g...

A laboratory plasma–wall interaction-based astrophysical gravito-electrostatic sheath (GES) model is methodologically applied to study the dynamic stability of the magnetoactive bi-fluidic solar plasma system in the presence of turbulence effect. The spherically symmetric GES-model formalism couples the solar interior plasma (SIP, internally self-g...

The evolutionary existence of plasma fireballs is a generic phenomenon realizable in diversified physical plasma-dominated circumstances starting from the laboratory to the astrocosmic scales of space and time. A fair understanding of such fireballs and associated instabilities is indeed needed to enrich astroplasmic communities from various perspe...

Motivated by the recent Magnetospheric Multiscale (MMS) observations of oblique electron acoustic waves, we addressed the generation mechanism of the observed waves by utilizing the reductive perturbation technique. The nonlinear Zakharov-Kuznetsov (ZK) equation is derived for collisionless, magnetised plasma composed of cool inertial background el...

We analyze the propagatory nucleus-acoustic wave (NAW) modes excitable in the completely degenerate (CD) core and in its nearly degenerate (ND) ambience of the ONe and CO white dwarfs (WDs). It is based on three-component spherical hydrodynamic quantum plasma consisting of tiny non-thermal quantum electrons, classical thermal light nuclear species...

It is a usual practice to assume that matter and its various phases in normal configuration extensively obey a polytropic equation of state (EoS) with a generalized semiempirical pressure-density functional relationship, P = f(ρ), a polytropic law or a polytropic rule. This law is explicitly given as P = KPρΓ, = KPρ1+(1/nP); where KP is called the...

The omnipresence of dust particles in space and astrophysical plasmas has attracted numerous researchers to study the collective excitation and propagation dynamics of different linear and non-linear eigen-structures in diversified astrocosmic circumstances. To name a few, dusty plasmas are naturally found in planetary rings, interplanetary space,...

The gravito-electrostatic sheath (GES) model, originally formulated to see the surface origin of the solar wind plasma (SWP) originating from the solar interior plasma (SIP) through the quasi-linear coupling solar surface boundary (SSB), is revisited. In our model, we consider the non-thermal (κ-distributed) electrons and inertial ions as the const...

A laboratory plasma-wall interaction-based astrophysical gravito-electrostatic sheath (GES) model, which has originally been reported to investigate the solar surface emission mechanism of the solar wind, is herein methodologically applied to analyze the dynamic stability of the entire non-thermal solar plasmas. The effects of non-thermality, fluid...

Award of Reviewer Certificate (Taylor & Francis)

We propose a relativistic quantum plasma model to analyze the ion-acoustic (IA) wave mode stability in gyromagnetoactive spherical electron-ion plasma in a quantum hydrodynamic fabric. It co-includes the Coriolis rotation force, electrostatic confinement pressure, Bohm potential, etc. The restoring force is sourced in the relativistically degenerat...

The gravitoelectrostatic sheath (GES) model, originally formulated to see the surface origin of solar wind plasma (SWP) originating from the solar interior plasma (SIP) through the quasi-linear coupling solar surface boundary (SSB), is revisited. In our model, we consider the non-thermal (κ-distributed) electrons and inertial ions as the constituti...

Advanced research training: ProQuest

A relativistic quantum hydrodynamic model is used to study the IAW in ultradense gyromagnetoactive spherical plasma system. It consists of a two-fluid system, namely the quantum-mechanical electronic fluid and the classical heavy ionic fluid. The considered system evolves under the conjoint action of the Coriolis rotation, Lorentz force field, quan...

The evolutionary dynamics of plasma fireball sheath instability, which is widely found in diversified laboratory plasmas, has been an interesting topic of research in the plasma physics community for years [1]. As far as the triggering free current source behind is concerned, it is consistent and correlative with various traditional plasma instabil...

Oxford Star User

A laboratory plasma-based astrophysical gravito-electrostatic sheath (GES) model, which has originally been reported to establish the solar surface emission mechanism of the solar wind (solar interior plasma, SIP; and solar wind plasma, SWP) in the framework of plasma-wall interaction processes, is herein methodologically applied to study the dynam...

A theoretic model to investigate the dynamics of the longitudinal nucleus-acoustic waves (NAWs) in gyrogravitating electrostatically confined degenerate quantum plasma (DQP) system in spherically symmetric geometry is constructed. The model setup consists of non-degenerate heavy nuclear species (HNS), lighter nuclear species (LNS), and quantum dege...

A nonlinear nonideal generalized magnetohydrodynamic (MHD) model is developed to explore the evolutionary dynamics of nonlinear wave-structural patterns naturalistically excitable in inhomogeneous protoplanetary disks (PPDs). A local nonlinear perturbation theory (multiscale analysis) over the magnetohydrostatic homogeneous equilibrium of the axisy...

Certificate by Oxford University Press

Acting as "Expert Reviewer" for reputed international publishers, such as Elsevier, IEEE, Springer, Taylor & Francis, Wiley, IoP, AIP, etc.

Award of certificate by Wiley

The evolutionary instability dynamics, which is naturally excitable in an astrophysical complex gyrogravitating partially ionized molecular cloud in a magnetic field, is herein semi-analytically investigated. It is rooted in a non-ideal classical non-relativistic magnetohydrodynamic (MHD) mean-fluidic model fabric. The effects of fluid kinematic vi...

Invited resource person as a speaker in an international webinar on "Astrophysics & Space Science"

Acceptance of work for publication in NATURE (Scientific Reports)

Expert Reviewer in Taylor & Francis Group

A kinetic theory formulation of the pulsational mode of gravitational collapse (PMGC) in a complex unmagnetized self-gravitating partially ionized dense molecular cloud (DMC) is proposed. Applying a linear normal mode analysis, a quintic linear dispersion relation with a unique set of multi-parametric plasma-dependent coefficients is obtained. The...

My certificate for reviewing nine papers published by AIP-APS

Reviewer of Physica Scripta (by IoP)

The linear stability excitation dynamics in a complex, low-density, partially-ionized gyro-gravitating dust molecular cloud (DMC) is theoretically studied in a non-ideal magnetohydrodynamic (MHD) fluid fabric. The novelty lies in the tidal force effects coming from the external remote gravitating objects destabilizes the cloud. It is seen that the...

The lowest order inertial correction for the plasma thermal electrons usually reduces the plasma ion flow Mach number in normal transonic plasma layer, and thereby, likely to modify the normal kinetics of plasma sheath-induced oscillation and modes. The same effect is projected to affect the formation mechanism of the gravito-electrostatic sheath (...

Applying the basic physical mechanism of plasma sheath formation, a plasma-based GravitoElectrostatic Sheath (GES) model for the steady-state description of the Solar Surface Boundary (SSB) origin mechanism of the quasineutral Solar Interior Plasma (SIP) subsonic flow, and subsequently, its transonic transition into the Solar Wind Plasma (SWP) supe...

ABSTRACT: MODIFIED ION-ACOUSTIC WAVE IN RELATIVISTIC QUANTUM PLASMAS We propose a relativistic quantum plasma model to analyze the ion-acoustic wave (IAW) mode stability behaviours in spherical gyromagnetoactive electron-ion plasmas. It includes the conjoint action of the Coriolis rotation, electrostatic confinement pressure, Bohm potential, etc....

A generalized nonideal magnetohydrodynamic (MHD) model to explore the excitation dynamics of the gravitational (Jeans) instability in a spherical complex molecular cloud is reported. It includes the realistic effects of viscoelasticity, buoyancy, polytropicity, volumetric expansion, and so forth. A standard technique of spherical normal mode analys...

The main goal here is to study theoretically the formation of plasma sheath in an inhomogeneous dusty plasma. The effect of weak ionization of the dust grains as similar to the Townsend discharge has been incorporated to see how it influences the evolution of sheath. Sheath equation has been derived to describe the properties of sheath structures a...

Award of Certificate by Oxford University Press

We investigate the dynamics of the dust acoustic wave (DAW, low-fugacity) and the dust Coulomb wave (DCW, high-fugacity) in self-gravitating magnetized viscoelastic spherical dusty astroclouds. It consists of the inertial dust grains with variable charge alongside the nonthermal electrons and ions in a generalized hydrodynamic framework. A spherica...

A theoretic model to investigate the dynamics of the longitudinal nucleus-acoustic waves (NAWs) in gyrogravitating electrostatically confined degenerate quantum plasma (DQP) system in spherically symmetric geometry is constructed. The model setup consists of non-degenerate heavy nuclear species (HNS), lighter nuclear species (LNS), and quantum dege...

The evolutionary dynamics of bimodal pulsational mode, arising because of the long-range conjugational gravito-electrostatic interplay in viscoelastic polytropic complex multicomponent astroclouds with partial ionisation, is classically examined using a non-relativistic generalised hydrodynamic model approach. The equilibrium distribution of the di...

Astromodal wave dynamics in multifluidic structure-forming cloud complexes

We present a theoretical model formalism to investigate the collective wave stability dynamics in a magnetized three-component dusty plasma with the non-thermal electrons and ions in the generalized hydrodynamic (GH) framework. It mainly considers the effects of non-local self-gravity, non-thermal pressure, and dust-charge fluctuations in a spheric...

A theoretic model to investigate the evolutionary excitation dynamics of the nucleus-acoustic waves (NAWs), which are the propagatory longitudinal oscillations set up due to the interplay between the nuclear inertia (by heavy nuclei) and the thermal elasticity (by degenerate electrons), in a rotating self-gravitating degenerate quantum plasma syste...

Invited Speaker (Summit Presenter, Astrophysics & Space Research, CASR-2020)

My role as a reviewer in the Astrophysical Journal (by IoP)