Nonlinear solitary waves (oscillitons) in dusty magnetized pair plasmas

Abstract

Nonlinear theory is presented for solitary waves propagating parallel to the magnetic field in a cold plasma with charged dust grains or heavy ions. The particular case of an imbalanced electron-positron plasma with a portion of the charge residing on the dust particles is investigated. The charge imbalance plays a similar role to unequal ion and electron masses, in that an “oscilliton” type solution is found, using an approximate analytic solution, as well as numerical solutions of approximate equations and the full non-relativistic equations. Circularly polarized oscillitons occur for the electron-positron plasma for a Mach number above a critical value which is <1, in contrast to the pure pair plasma which has a linearly polarized non-oscillatory nonlinear wave solution for Mach number >1.