Ion acoustic soliton with thermal ions and non-thermal electrons in a high-relativistic electron-positron-ion plasma

Abstract

In this investigation, both compressive and rarefactive solitons are shown to exist in electron-positron-ion plasma consisting of thermal positrons, non-thermal electrons, and high relativistic thermal ions. The reductive perturbation method (RPM) is used to derive the nonlinear Korteweg-de Vries (KdV) equation from the governing normalized basic set of equations. It is shown that only the fast ion-acoustic mode may produce the small amplitude rarefactive and compressive KdV solitons. It has been observed that the addition of variable ion species temperature dramatically alters the fundamental characteristics of amplitude and width. Moreover, the amplitude decreases as the ion to electron temperature ratio rises. The soliton's amplitude is also increased by the relativistic factor. High-relativistic electron-positron-ion plasmas are found in extreme astrophysical environments like pulsar magnetospheres, gamma-ray bursts, and active galactic nuclei. These plasmas’ wave and soliton activity can shed light on the dynamics of these astrophysical systems.