Nonlinear oscillations of dust-acoustic waves in non-Maxwellian dusty plasma under the gravitational force effect

In this paper, the role of dust grain's gravitational force on the nonlinear dust-acoustic oscillations in non-Maxwellian dusty plasma is analyzed. It is shown that increasing the number of non-thermal ions causes the diminution of the electrostatic potential's amplitude and a reduction in the number of oscillations introduced by the gravitational force. We have also found that reducing the size of the dust grain induces qualitatively the same effects as an increase in the number of non-thermal ions and when the gravitational force is considered, the electric charge exhibits oscillatory profile and becomes less negative far away from the origin. This result may be interesting in the study of astrophysical plasmas where the electromagnetic force is smaller than the gravitational one such as in the Halley Comet.