Thermal Instability of a Finite-Larmor-Radius Hall Plasma Under Rotation and Variable Gravitational Field in Porous Medium

The thermal instability of a rotating plasma in a porous medium is considered in the presence of a uniform vertical magnetic field to include the Hall-current, finiteLarmor-radius (FLR) and variable gravitational field effects. It is found that the principle of exchange of stabilities is valid in the absence of rotation and magnetic field (hence Hall-current). The uniform vertical magnetic field (and hence an FLR and Hall-current) and rotation effects introduce oscillatory modes in the system which were non-existent in their absence. The system is stable/unstable depending upon certain conditions in the presence of rotation, medium permeability and magnetic field (hence Hall-current and an FLR). The Rayleigh number is found to increase with the increase of the magnetic field (and hence an FLR and Hall-current), rotation and medium permeability.