Gravitational instability of an anisotropic and viscoelastic plasma

Frontiers of Physics and Plasma Science

Sharma, P.K.^1 ; Tiwari, Anita^1 ; Khan, Nusrat^1 ; Argal, Shraddha^1

University Institute of Technology, Barkatullah University, Bhopal (M.P.)

462026, India^1

关键词: Anisotropic pressure;    Dispersion relations;    Gravitational instability;    Hydrodynamic fluid models;    Longitudinal modes;    Normal mode analysis;    Stabilizing effects;    Visco-elastic mediums;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/836/1/012020/pdf
DOI  :  10.1088/1742-6596/836/1/012020

来源: IOP

【 摘 要 】

The effect of pressure anisotropy is studied on the growth rate of gravitational instabilities in a viscoelastic medium. The problem is constructed with generalized hydrodynamic fluid model and Chew-Goldberger-Low fluid model for anisotropic pressure then a general dispersion relation for the viscoelastic medium is obtained using the normal mode analysis. The general dispersion relation is reduced for propagation along the magnetic field and propagation perpendicular to the magnetic field. These two modes are discussed for the classical or hydrodynamic and kinetic limits and conditions for jeans instability are obtained. We found that condition of Jeans instability is modified for viscoelastic medium under kinetic limit and depends on compressional viscoelastic mode. Numerical analysis for longitudinal mode for kinetic regime shows that the velocity of compressional viscoelastic mode has a stabilizing effect on the growth rate of Jeans instability. In the transverse mode, the Alfven velocity for kinetic regime has a stabilizing influence on the Jeans instability.