Ion dynamics and gravitational instability of a dusty plasma

The gravitational instability of a dusty plasma with ion dynamics taken into account is studied. For the range of parameters relevant to planetary rings and interstellar media, we demonstrate that the inclusion of ion dynamics cannot cause additional destabilization of a gravitating dusty plasma system. Streaming of the cold ions, on the other hand, enhances the Jeans condensation of a dusty plasma. Consistency of the results with previous work and new aspects arising owing to consideration of ion dynamics is discussed.