Periodic kinetic Alfvén waves and overtaking between multi-solitons in nonthermal electron–positron–ion plasma

Abstract

In this paper, the formation of periodic (cnoidal) and solitary kinetic Alfvén waves (KAWs) in nonthermal electron–positron–ion plasma has been illustrated. The KdV equation has been derived by using the reductive perturbation technique. The Sagdeev potential method is used to obtain the solution of KdV equation for examining the dynamics of periodic KAWs. Further, Hirota bilinear method is applied to examine the overtaking process and the expressions of phase shifts of multi-solitons have been determined. Only positive potential kinetic Alfvénic (KA) solitary and periodic waves are evolved in the given plasma environment. The influence of plasma beta, positron density, angle of propagation, nonthermality of electrons and positrons has been investigated on the behaviour of periodic (cnoidal) KAWs. The combined impact of density, nonthermality of electrons as well as positrons has vastly modified the phase shifts of double-as well as triple-solitons. This investigation may have applications for particle acceleration and energy transportation in galactic nucleus and interstellar medium where nonthermal electron and positron pairs exist.