Electron–acoustic solitons in multi-species space plasmas: Supersoliton perspectives

Abstract Since the discovery of the electrostatic wave emissions such as broadband electrostatic noise (BEN) and electrostatic hiss in space plasmas, both kinetic and nonlinear fluid studies have been employed to study the properties and characteristics of the solitons. Here, we use the Sagdeev pseudo-potential method to investigate the existence of the high-frequency supersolitons in a four-component unmagnetised plasma model composed of hot, warm, and cool electrons and cool ions species. All species are treated as adiabatic and are considered as stationary in our soliton analysis. Although the model supports both slow and fast electron–acoustic soliton, only the solutions of a negative-polarity supersoliton solution of the fast electron–acoustic type are discussed in this research study. It is shown that high-frequency supersoliton exists in a very narrower region of parameter space. Furthermore, the lower and upper Mach numbers for the supersolitons are computed and discussed. We have constructed the existence domains of the supersolitons, and the maximum potential amplitudes are computed. Positive potential supersolitons are not found in our numerical analysis. The importance and applications of our numerical findings in space-plasma environments are also discussed.