Nonlinear interaction of slow Alfvén wave with ion acoustic wave and applications to space plasma

The paper is concerned with the analytical study of nonlinear coupling of slow Alfvén wave (SW) with ion acoustic waves (IAWs) in high-β and low-β plasmas. Here the pump wave (SW) number density gets perturbed in the presence of IAW. The model equations of IAW and SW turn out to be the modified Zakharov system of equations when the ponderomotive nonlinearities are incorporated in the IAW and SW dynamics. Growth rate of modulational instability has been calculated. The relevance of these investigations for solar wind plasma and solar coronal plasma has also been discussed.