Stability of nucleus-acoustic waves in completely degenerate white dwarf cores and their nearly degenerate ambience

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 (LNS), and classical thermal heavy nuclear species (HNS). The inner concentric layer-wise electronic pressures are judiciously modelled. The electronic energy distribution governed by the Fermi-Dirac (FD) thermostatistical distribution law involves both the thermodynamical temperature and chemical potential. Our exploration emphasizes on the transition state between the thermodynamical temperature and the Fermi temperature for the borderline regions of intermediate degeneracy. A normal spherical mode analysis procedurally yields a sextic generalized linear dispersion relation highlighting the plasma multiparametric dependency of the NAW-features. A numerical illustrative platform is constructed to investigate the full NAW propagatory and dispersive behaviours. We demonstrate that the NAW in ONe (CO) WDs exhibits sensible growth characteristics at near the transcritical (supercritical) wave zone. The temperature-sensitivity of the NAW-growth is more (less) prominent in ONe (CO) WDs. It could be hopefully useful to see the internal structure of compact astroobjects from the asteroseismic probe-perspective of collective quantum interaction processes.Comment: 25 pages, 20 figures, 1 tabl

Solitary-train dynamics in viscoelastic nonthermal astroplasmas

The nonlinear fluctuation dynamics in a self-gravitating nonthermal viscoelastic complex fluid is semi-analytically investigated. It considers the thermostatistical κ-distribution law for the weakly coupled lighter constitutive particles against the strongly coupled heavier constituents treated as a complex viscoelastic fluid. A multi-scale analysis reduces the fluid equations into a Korteweg-de Vries (KdV) equation with a unique set of multiparametric coefficients. It reveals excitations of solitary trains of unique interesting patterns. A further confirmation about the eigen-structures is provided with the help of phase-plane analysis. It is specifically shown that the thermostatistical power-law exponent (κ) acts as a destabilizing source for the nonthermal plasma fluids against the gravitational collapse in all the diversified conditions, and so forth. Different characteristic features of the patterns in different thermodynamical conditions are discussed together with a synoptic indication to applicability scope

Athermal GES-based solar plasma stability with sphero-logabarotropic special effects

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-electrostatically via the interfacial diffused solar surface boundary (SSB). The constitutive electrons are thermostatistically framed in the κ-distribution laws via the Tsallis thermostatistics. In contrast, the heavier ions are treated as an inhomogeneous fluid. The turbulent degrees of freedom are accounted through the Larson nonlinear logabarotropic equation of state in curved geometry. A spherically symmetric wave analysis over the perturbed GES structure results in a unique pair of distinct linear dispersion laws (SIP plus SWP) without any typical quasi-classic approximation. A numerical illustrative platform for the dispersion analysis specifically shows that an antikink-type (kink-type) impulsive rarefactive (compressive) propagatory boost due to irregular dispersion is experienced by the fluctuations at the heliospheric core (photospheric SSB). We see that the thermostatistical parameter (Tsallis power-law tail index κ) acts as a unique form of acceleration agency for both the SIP and SWP instabilities to proliferate. At the last, the explorative semi-analytic results are contextually compared with the realistic domains of the collective excitation of the helioseismic waves and SSB oscillations

An elog-KdVB dynamics in non-thermal solar plasmas

This paper deals with a continued study on the basis of the gravito-electrostatic sheath (GES) model to explore the excitation of solitary and shock-like wave structures evolving in the non-thermal solar plasmas. The method applied here is based on a nonlinear local perturbation analysis over the GES structure equations designed in a thermostatistically modified form to arrive at an extended logatropic Korteweg-de Vries-Burgers (elog-KdVB) equation with a unique linear derivative source, which has in principle, a special set of multiparametric coefficients dependent on the diversified solar plasma parameters. A constructive numerical integration of the elog-KdVB equation yields the excitation of rarefactive shock-like wave patterns supported in the solar plasmas. Their noticeable unique characteristic feature is the naturalistic existence of distorted non-uniform tails. The shock-wave amplitude increases with the increase in the thermostatistical power (κ), and vice versa. In contrast, the shock-tail width decreases with the increase in the thermostatistical distribution power (κ), and vice versa. It implicates that the shock-tail width vanishes in the Boltzmann thermostatistical limit ($\kappa \to \infty$ ). The corresponding gradients, phase portraits, and curvature dynamics associated with the fluctuations are illustratively depicted. The microphysical details behind the dynamics are analyzed. The elog-KdVB dynamical results explored are bolstered with the reinforcement of the earlier multispace satellitic observations and original probe measurements reported elsewhere. The non-trivial implications and applications are summarily highlighted in the real helioseismic contextual linkage

Dynamics of flow-induced instability in gyrogravitating complex viscoelastic quantum fluids

The flow-induced excitation dynamics of electrostatic dust-streaming instability mode supported in illimitable complex gyrogravitating viscoelastic quantum plasma fluids in a spatially flat-geometry configuration is analyzed in the non-relativistic regime. The constitutive lighter electrons (larger de-Broglie wavelength) are only treated as quantum degenerate particles leaving the rest as classical. The semi-analytic formalism is based on the fabric of generalized quantum hydrodynamic model ameliorated with a dimensionality-dependent gradient correction prefactor in the electronic quantum Bohm potential. The nonlinear logatropic barotropic effects arising from fluid turbulence is included. It assumes that perturbations in the longitudinal direction do not excite any transverse mode counterparts. A standard normal mode analysis yields a linear generalized (quartic) dispersion relation. A numerical illustrative perspective is executed in the extreme hydro-kinetic regimes. Active agencies affecting the fluid stability are identified and discussed. It is seen that the quantum parameter plays a destabilizing role in both the hydro-kinetic regimes. The equilibrium dust drift acts as a stabilizing agent in both the regimes. The quantum correction prefactor introduces stabilizing and destabilizing effects in the hydro-kinetic regimes; respectively. In addition, the Coriolis rotation introduces stabilizing effect in both the regimes. Finally, implications and applications of our results in the context of gyrogravitational compact dwarf stars and their environs in are summarily outlined

Nonextensive GES instability with nonlinear pressure effects

We herein analyze the instability dynamics associated with the nonextensive nonthermal gravito-electrostatic sheath (GES) model for the perturbed solar plasma portraiture. The usual neutral gas approximation is herewith judiciously relaxed and the laboratory plasma-wall interaction physics is procedurally incorporated amid barotropic nonlinearity. The main motivation here stems from the true nature of the solar plasma system as a set of concentric nonlocal nonthermal sub-layers as evidenced from different multi-space satellite probes and missions. The formalism couples the solar interior plasma (SIP, bounded) and solar wind plasma (SWP, unbounded) via the diffused solar surface boundary (SSB) formed due to an exact long-range gravito-electrostatic force-equilibration. A linear normal mode ansatz reveals both dispersive and non-dispersive features of the modified GES collective wave excitations. It is seen that the thermostatistical GES stability depends solely on the electron-to-ion temperature ratio. The damping behavior on both the scales is more pronounced in the acoustic domain, K→∞, than the gravitational domain, K→0; where, K is the Jeans-normalized angular wave number. It offers a unique quasi-linear coupling of the gravitational and acoustic fluctuations amid the GES force action. The results may be useful to see the excitation dynamics of natural normal modes in bounded nonextensive astero-environs from a new viewpoint of the plasma-wall coupling mechanism

A non-ideal MHD model for structure formation

The evolutionary initiation dynamics of triggered planetary structure formation is indeed a complex process yet to be well understood. We herein develop a theoretical classical model to see the gravitational fragmentation kinetics of the viscoelastic non-ideal magneto-hydro-dynamic (MHD) fabric. The inhomogeneous planetary disk is primarily composed of heavier dust grains (strongly correlated) together with relatively lighter electrons, ions and neutrals (weakly correlated) in a mean-fluidic approximation. A normal harmonic mode analysis results in a quadratic dispersion relation of a unique shape. It is demonstrated that the growth rate of the MHD fluctuations (magnetosonic) contributing to the planet formation rate, apart from the wave vector and its projection orientation, has a pure explicit dependency on the viscoelastic parameters. The analysis specifically shows that the effective generalized viscosity $(\chi)$ , viscoelastic relaxation time $(\tau_{m})$ , and K-orientation $(\theta)$ play as destabilizing agencies against the non-local gravitational disk collapse. The relevancy is briefly indicated in the real astronomical context of bounded planetary structure formation and evolution

Instability behaviour of cosmic gravito-coupled correlative complex bi-fluidic admixture

The gravitational instability of an unbounded infinitely extended composite gravitating cloud system composed of gravito-coupled neutral gaseous fluid (NGF) and dark matter fluid (DMF) is theoretically investigated in a classical framework. It is based on a spatially-flat geometry approximation (1D, sheet-like, boundless) at the backdrop that the radius of curvature of the gravito-confined bi-fluidic-boundary is much larger than all the hydro-characteristic scale lengths of interest. The relevant collective correlative dynamics, via the lowest-order mnemonic viscoelasticity, is mooted. We apply a standard formalism of normal mode analysis to yield a unique brand of generalized quadratic dispersion relation having variable multi-parametric coefficients dependent on the diversified equilibrium properties. It is parametrically seen that the DMF flow speed and the DMF viscoelasticity introduce stabilizing effects against the composite cloud collapse. The instability physiognomies, as specialized extreme corollaries, are in good accord with the previously reported predictions. The analysis may be widely useful to see the gravito-thermally coupled wave dynamics leading to the formation of large-scale hierarchical non-homologous structures in dark-matter–dominated dwarf galaxies

Nonlinear waves in viscoelastic magnetized complex astroplasmas with polarized dust-charge variations

A nonextensive nonthermal magnetized viscoelastic astrofluid, compositionally containing nonthermal electrons and ions together with massive polarized dust micro-spherical grains of variable electric charge, is allowed to endure weakly nonlinear perturbation around its equilibrium. The nonextensivity originating from the large-scale non-local effects is included via the Tsallis thermo-statistical distribution laws describing the lighter species. Assuming the equilibrium as a homogeneous hydrostatic one, the dust polarization effects are incorporated via the conventional homogeneous polarization force law. The perturbed fluid model evolves as a unique conjugate pair of coupled extended Korteweg-de Vries (e-KdV) equations. A constructed numerical tapestry shows the collective excitations of a new pair of distinct classes of nonlinear mode structures in new parametric space. The first family indicates periodic electrostatic compressive eigenmodes in the form of soliton-chains. Likewise, the second one reveals gravitational rarefactive solitary patterns. Their microphysical multi-parametric dependencies of the eigen-patterns are illustratively analyzed and bolstered. The paper ends up with some promising implications and applications in the astro-cosmo-plasmic context of wave-induced accretive triggering processes responsible for gravitationally bounded (gravito-condensed) astro-structure formation, such as stellesimals, planetsimals, etc

Modified gravito-electrostatic sheath in the presence of turbu-magnetic pressure effects

The gravito-electrostatic sheath (GES) model, previously formulated to investigate the equilibrium properties of the Sun and its unbounded atmosphere coupled via the interfacial solar surface boundary (SSB) under the gravito-electrostatic interplay, is re-examined. It is modified, for the first time, with the self-consistent inclusion of turbu-magnetic pressure effects originating from intrinsic continuous instability processes. The role of the new effects is interestingly realized through considerable changes in the dynamic properties of the solar plasma system on both the bounded and unbounded scales. The SSB, as a result of the outward turbu-magnetic action relative to the inward self-gravitating one, is found to shift radially outwards by 5.71% relative to the sheer GES model, and by 7.50% inwards relative to the pure uniformly magnetized counterpart. The sonic point moves inwards by 30% in the former, and by 24% in the latter; respectively. It is further found that the floating surface and floating potential increase by 47% each relative to the GES; and by 27% and 160% relative to the pure magnetic case; respectively. The implications and applications are discussed in the panoptical light of real astronomical observations alongside the facts, faults and future refinements