A Melnikov analysis and chaotic dynamics of low-frequency dissipative ion-acoustic solitons in multicomponent plasmas

This study investigates the nonlinear dynamics of low-frequency ion-acoustic waves in a four-component unmagnetized plasma consisting of warm adiabatic ions, κ -distributed superthermal electrons and positrons, and isothermal electrons. Using a reductive perturbation approach, we derive a damped, forced modified Korteweg-de Vries-Burgers equation to describe the evolution of compressive ion-acoustic solitary waves (IASWs). The properties of these IASWs are significantly influenced by key plasma parameters, including the temperature ratio between superthermal electrons and positrons, the density ratio of superthermal to isothermal electrons, the temperature ratio of warm ions to superthermal electrons, and the superthermal index. Further, we apply Melnikov’s analytical method to identify criteria for the onset of chaos when an external periodic force is introduced. Supported by numerical simulations including time series, phase portraits, and Poincaré sections, our analysis reveals that the system can exhibit regular periodic oscillations, quasi-periodic regimes, and chaotic dynamics depending on the strength and frequency of the external perturbation. These results offer new insights into the transition to chaos in dissipative plasmas and may help interpret nonlinear wave phenomena in environments where collisions and external forcing are present.