Electrostatic dust modes in self-gravitating dense dusty plasmas with highfugacity

Self-gravitational instabilities in dusty plasmas have been investigated ov er different regimes of dust fugacity. The Jeans instability associated wit h dust-acoustic waves is shown to exist in the low fugacity regime. On the other hand, in dense dusty plasmas characterized by high fugacity, the inst ability is found to occur at much smaller scale sizes, and is associated wi th dust-Coulomb waves. The general case of arbitrary Fugacity corresponding to dust charge-density waves and the associated Jeans instability has also been discussed. A comparison between the critical Jeans lengths For the di fferent cases has been carried out. (C) 2000 Elsevier Science B.V. All righ ts reserved.