Dust-acoustic waves with finite OAM in a self-gravitating dusty plasma with superthermal energetic tails of electrons and ions

Abstract

The kinetic instability of twisted dust-acoustic (DA) wave with distinct orbital angular momentum states is studied in an unmagnetized self-gravitating superthermal dusty plasma. For this purpose, the linearized Vlasov–Poisson equations are solved together by expressing the perturbed distribution function, electrostatic and gravitational potentials in terms of Laguerre–Gauss functions or solutions. A generalized plasma dielectric constant is derived and the existence conditions for the damping/growth rates are identified. The impact of streaming speed, dust self-gravitation, superthermality and twist parameters are numerically examined on the growth rate instability. It has been found that parametric variation significantly modifies the threshold conditions and associated growth rate instability of twisted DA waves. The relevance of the present results to interstellar dust clouds is illustrated, where massive dust grains follow a Maxwellian distribution in addition to superthermal electrons and ions.