GRAVITATIONAL INSTABILITY IN THE PRESENCE OF HALL-CURRENT

Abstract

The effect of the inclusion of the Hall current due to electron dynamics on the gravitational instability of a finitely conducting medium has been studied using the modifications indicated by Cowling and Lighthill including uniform rotation. It has been found that excepting for a few special cases, Jeans criterion still determines the gravitational instability The inclusion of Hall current affects the criterion only when the disturbances are propagated transverse to the magnetic field. Numerical estimates of these new dimensions have been obtained and compared with Jeans' result. The conclusions were also justified on the basis of physical arguments.