Dust Acoustic Solitary Waves Excited By Gravity In A Collisional Plasma

Up to now, there are lots of investigation about dusty plasma, and it is accepted generally that there are acoustic solitary waves in the system that collision is no taken into account, in the same way, it is accepted generally that there are no acoustic solitary waves in a collisional dusty plasma because of damp arose from collision that is considered a constant. Let's consider a collisional dusty plasma set in a gravitational field and contains electrons, ions, neuter gas molecules and dust grains, if the electrons, the ions and the neutral gas molecules are taken to be essential massless and unaffected by gravity, the dust grains fall through the other plasma components under the effect of gravity, electrons, ions and dust grains collide with the neutral gas molecules with constant collision frequencies respectively. So there are no acoustic solitary waves in this system. In fact, the neutral gas background is not always uniform because of collision with the other components. It is this very consideration that we take a disturbance to collision frequency, then, there are acoustic solitary waves in this collisional dusty plasma. In addition, in order to understand the dust acoustic waves excited by gravity in a collisional plasma, we have solved the KadomfsovO-Pefrishvili(KP) equation come from this system with self-similar method, and obtained the self-similar solutions. Furthermore, we have extended the self-similar method that be used to solve low dimensional nonlinear partial differential equation(NPDE) to solution of high dimensional NPDE(s).