HEAD-ON COLLISION OF THE (MODIFIED) KDV DUST ION-ACOUSTIC SOLITONS IN HIGHLY RELATIVISTIC ELECTRON-POSITRON-ION COMPLEX PLASMAS

Face-to-face (Head-on) dust ion-acoustic solitons collision in highly relativistic complex plasmas are theoretically reported. This plasma model is composed of relativistic inertial warm ions, inertialess nonthermal electrons, positrons, and stationary negatively charged massive dust grains. By employing the extended Poincaré-Lighthill-Kuo technique, we derive the coupled planar Korteweg-de Vries (KdV) and modified planar KdV (mKdV) equations to explore the impact of soliton collisions on amplitude and phase shifts, taking into account highly relativistic parameters. It is found that both positive (negative) phase shift exists, and then the nonlinear coefficient of dust ion-acoustic waves increases (decreases) for KdV (mKdV) due to the rise of the highly relativistic δ parameter. This investigation reveals that the compressive (rarefactive) solitons and the positive (negative) phase shifts are generated depending on the highly relativistic δ, the nonthermality of electron α_e, and the dust charge density ratio µ_d. The amplitude of the soliton is not enhanced after collision. These investigations’ results help many researchers understand the different changes observed in the plasma environment, such as Jupiter’s magnetosphere, auroral zone, the warm regions on dust rings at the galaxy’s center, and many others.