NONLINEAR DUST ACOUSTIC-WAVES WITH DUST CHARGE FLUCTUATIONS

Nonlinear dust-acoustic waves in an unmagnetized dusty plasma have been investigated by taking into account dust-grain charge perturbations. For small, but finite. amplitudes the waves are shown to be governed by a Boussinesq-like nonlinear equation coupled to the charge fluctuation equation. For unidirectional propagation, the equations reduce to a Korteweg-de Vries (K-dV) equation with a source term. At early times, localized solutions are found to be damped due to the dust charge fluctuations. Different limiting cases of the general equations are also discussed.