Coexistence of low-frequency compressive and rarefactive electrostatic excitations in electronegative plasmas having Cairns–Tsallis-distributed electrons

The present study investigates the coexistence of arbitrary amplitude positive and negative potential ion-acoustic solitary waves (IASWs) in an unmagnetized electronegative plasma comprising inertial cold ions and inertialess electrons exhibiting a Cairns–Tsallis distribution. The fluid model equations are reduced to an energy balance equation using Sagdeev’s approach. The Sagdeev potential is analyzed based on the criteria for the existence of solitary waves. The existence regions for the ion-acoustic waves (IAWs) are precisely determined based on the related physical parameters. The current model supports both compressive and rarefactive IAWs. This study demonstrates the significant influence of related physical parameters, such as the negative density ratio, nonextensive parameter, and nonthermal parameter, on the IASWs behavior. The present study is significant in understanding the nonlinear structures dynamics observed in the lower part of the magnetosphere and the upper part of the ionosphere through various satellite missions.