Ion-acoustic solitary waves and their interaction in a weakly relativistic two-dimensional thermal plasma

This paper discusses the existence of ion-acoustic solitary waves and their interaction in a weakly relativistic two-dimensional thermal plasma. Two Korteweg-de Vries equations for small but finite amplitude solitary waves in both xi and eta directions are derived. The phase shifts and trajectories of two solitary waves after the collision with an arbitrary angle alpha are also obtained. The effects of parameters of the normalized ion temperature sigma, the ratio of heat capacity delta, the relativistic factor F-gamma, and the colliding angle alpha on the amplitudes, the widths and the phase shifts of both the colliding solitary waves are studied. The effects of these parameters on the new nonlinear wave created by the collision between two solitary waves are examined as well. The results suggest that these parameters can significantly influence the amplitude, the width of the newly formed nonlinear wave and the colliding solitary waves. The phase shifts of the colliding solitary waves strongly depend on the colliding angle alpha. Moreover, there are compressive solitary waves in such a system.