Dust-acoustic wave electrostatic and self-gravitational potentials in an opposite polarity dusty plasma system

An opposite polarity dusty plasma system (containing inertial positive as well as negative dust species and inertialess singly charged ion species) is considered. The nature of the electrostatic and self-gravitational potential structures (associated with the dust-acoustic waves) is identified by the numerical analysis of two coupled second-order nonlinear differential equations. The latter are Poisson's equations for electrostatic and self-gravitational potentials, where the positive and negative dust number densities (determined from their continuity and momentum equations) and the ion number density (determined from the Boltzmann law) are substituted. It is observed that the plasma system under consideration supports the dust-acoustic solitary structures associated with the positive as well as negative self-gravitational potentials but only with the positive electrostatic potential. The basic features of the electrostatic and self-gravitational solitary potential structures are studied. It is also found that the amplitude of the electrostatic and self-gravitational solitary potential structures decreases with the increase in the positive dust number density. The effects of other different dusty plasma parameters on these solitary potential structures are also identified. The applications of this investigation in some space and laboratory dusty plasma systems are pinpointed.