Solitary wave interaction in a cold collisionless plasma

The interaction between two solitary waves in a cold collisionless plasma h aving different velocities has been studied using the multiscale expansion method. The propagation of nonlinear waves through a cold collisionless pla sma is described by mKdV and KdV equations in(1 + 1) dimensions and mKP and KP equations in (2 + 1) dimensions for different orders of a small perturb ation parameter under the same time and space scale transformations. The in teracting system of equations are derived for mKdV and KdV equations as wel l as for mKP and KP equations. We have also analysed the interacting system of equations in (1 + 1 ) dimensions.