Arbitrary amplitude ion-acoustic solitary and shock waves in an unmagnetized electron–proton–ion nonthermal plasma

This study thoroughly examines the features of arbitrary amplitude ion-acoustic nonlinear structures, including both solitary and shock waves (double layers), in an unmagnetized electron–proton–ion plasma where electrons follow Cairns distributions and protons follow Maxwellian distributions. The Sagdeev pseudopotential (SP) approach is employed to reduce the fluid model equations into a pseudoenergy integral form that expresses potential energy as the SP. The SP is carefully analyzed to determine the precise conditions for the existence of both solitary and shock waves. Our detailed parametric analysis emphasizes the significant effect of electron nonthermality and proton concentration on the behavior, existence, and shape of ion-acoustic solitary and shock waves. This study provides important details about the complex, nonlinear wave phenomena in various space and astrophysical plasma environments, such as the solar wind, planetary magnetospheres, and ionospheres, where multicomponent plasmas with nonthermal particle distributions are common.