Ion-acoustic solitary waves in e-p-i plasmas with (r, q)-distributed electrons and kappa-distributed positrons

In this paper, we have studied the propagation of non-linear ion-acoustic waves in a plasma comprising of (r, q)-distributed electrons and kappa-distributed positrons. We have investigated the effect of complete electron distribution profile on the propagation of small, as well as arbitrary, amplitude solitons (via pseudopotential technique) by using generalized (r, q) distribution, which exhibits a spiky and flat top nature at low energies and a super-thermal tail at high energies. Interestingly, for negative values of r, solitons are formed with both polarities, positive (compressive) and negative (rarefactive), separately within a small amplitude limit and exist simultaneously in an arbitrary amplitude limit. We also found that the propagation of solitons has been affected by the change in parameters r, q, positron concentration, and electron to positron temperature ratio. The results presented in this study add to the fundamental understanding of the complete profile of the electron distribution function, high- and low-energy parts, and in the formation of compressive and rarefactive small and finite amplitude solitons in both space and astrophysical plasmas.