Dust-lattice waves: Role of charge variations and anisotropy of dust-dust interaction

Dust-lattice waves are studied in the framework of the one-dimensional particle string model. The dust-dust interaction potential is assumed to have an arbitrary dependence on the vertical and horizontal coordinates, which allows to take into account the wake field effects. Both the vertical and horizontal charge variations are also included into the model. The model yields the coupling between the vertical and horizontal (longitudinal) modes: the coupling coefficient is the sum of six terms, each caused by a different physical mechanism. It is shown that the coupling can trigger the resonance oscillatory instability, which has been already observed in experiments. It is also shown that a nonoscillatory instability can appear at small wave numbers due to the coupling. (C) 2005 American Institute of Physics.