Effect of polarization force on the Jeans instability in collisional dusty plasmas

The Jeans instability in collisional dusty plasmas has been analytically investigated by considering the polarization force effect. Instabilities due to dust-neutral and ion-neutral drags can occur in electrostatic waves of collisional dusty plasmas with self-gravitating particles. In this study, the effect of gravitational force on heavy dust particles is considered in tandem with both the polarization and electrostatic forces. The theoretical framework has been developed and the dispersion relation and instability growth rate have been derived, assuming the plane wave approximation. The derived instability growth rate shows that, in collisional dusty plasmas, the Jeans instability strongly depends on the magnitude of the polarization force.

Kinetic theory of Jeans'gravitational instability in millicharged dark matter system

The possibility of baryons cooled by a millicharged dark matter(mDM)via mDM–baryons scattering has recently been proposed to explain the observation discrepancy from the experiment to detect the global epoch of reionization signature(EDGES).In this sense,we analyze the Jeans instability of self-gravitational systems in the background of mDM under kinetic regime that the collisionless Boltzmann equation and Poisson equation have been combined to obtain the modified dispersion relation.It is shown that the effect of mDM is significant on the dynamics of gravitational collapse,i.e.,the presence of mDM makes the self-gravitational systems more difficult to collapse relatively.

Jeans gravitational instability withκ-deformed Kaniadakis distribution in Eddington-inspired Born-Infield gravity

Based on the framework of Kaniadakis’statistics and its related kinetic theory,the Jeans instability for selfgravitational systems in the background of Eddington-inspired Born-Infield(EiBI)gravity is revisited.A dispersion relation generalizing the Jeans modes is derived by modifying the Maxwellian distribution to a family of power law distributions parameterized by the κ parameter.It is established that theκ-deformed Kaniadakis distribution has significant effects on the Jeans modes of the collisionless EiBI-gravitational systems.And as expected,in the limitation κ→0,the corresponding results for Maxwellian case are recovered.The related result in the present work is valuable for the investigations involving the fields of astrophysics such as neutron stars,accretion disks,and relevant plasma physics,etc.

The instability analysis of self-gravitation systems under the perturbation with orbital angular momentum

Based on plasma kinetic theory, the instabilities of self-gravitation systems under perturbation with orbital angular momentum(OAM) are investigated, and the concept of twisted Jeans mode is introduced to describe the new phenomenon. The result shows that the growth rate of the Jeans instability is enhanced with the OAM parameter increased, while the critical wave number is consistent with the classical Jeans critical value. It is expected that the present results would give more insight into the evolution and dynamics of a self-gravitational system.

Effect of ion drag on a pulsational mode of gravitational collapse

The effect of ion drag on the pulsational mode of gravitational collapse(PMGC) is investigated within the partially charged dusty plasma model by fluid dynamics. It is found that the ion drag force significantly enhances the instability of the PMGC. In addition, it is shown that the instability of the PMGC is influenced by the ratio of the abundances of charged to neutral grains.These results can be relevant for the planetesimal formation in dark interstellar clouds.