Nonlinear dust acoustic waves in a self-gravitating and opposite-polarity complex plasma medium

The effects of the self-gravitational and the polarization forces on dust acoustic waves structure in a two-fluid complex plasma model are studied. The electrons and the ions obey the non-extensive distribution. The nonlinear dynamics of the massive positive and negative dust grains are considered. The reductive perturbation technique is applied to obtain a Zakharov-Kuznetsov equation. The nonlinear characteristics of the dust acoustic cnoidal (periodic) and solitary waves are investigated using the bifurcation theory. It is found that the dust acoustic wave properties depend strongly on the gravitational and the polarization parameters as well as the non-extensive indexes for electrons and ions. The possible applications of the present work to space plasma situations are discussed.