Gravitational instability of partially-ionized plasma in an oblique magnetic field

Abstract

The gravitational instability of an infinitely extending homogenous partially-ionized plasma permeated by an oblique magnetic field has been investigated here in the presence of the effects of Hall currents, magnetic resistivity and ion viscosity. The dispersion relation has been obtained and numerical calculations have been performed to obtain the dependence of the growth rate of the gravitationally unstable mode on the various physical effects. It is found that Jeans' criterion remains unchanged. The Hall currents and finite conductivity and collisions with neutrals are all found to have a destabilizing influence on the unstable mode of wave propagation of a gravitational instability of partially-ionized plasma. Ion viscosity is, however, found to have a stabilizing effect.