Oblique electrostatic modes in self-gravitating dusty plasmas.

Abstract

The propagation of oblique and perpendicular electrostatic modes in dusty self-gravitational magnetized plasmas is treated with due care for the small gravitational effects between charged dust particles and for the correct balance between electrostatic and gravitational forces. At purely oblique propagation, generalizations of the dust-cyclotron and dust-acoustic modes are found, where the latter can be subject to a Jeans instability. For strictly perpendicular propagation, only a mixed dust-acoustic and dust lower-hybrid mode occur at low frequencies. A Jeans collapse can be avoided by strong enough magnetic fields, the criterion for which is given.