Modulational instability of electron-acoustic waves in a plasma with Cairns–Tsallis distributed electrons

Abstract

The problem of the modulational instability (MI) of electron-acoustic waves (EAWs) in a plasma with Cairns–Tsallis distributed electrons is addressed. Using the standard multiple scale method, we derive a nonlinear Schrödinger-like equation. Electron nonextensivity and nonthermality are found to significantly influence the region stability of the EAWs. In particular, it is found that the critical value kc, beyond which the instability sets in, is slightly lowered as the electrons evolve far away from their Maxwellian thermodynamic equilibrium. Electron nonthermality renders more effective and more important the influence and role of nonextensivity. Moreover, the effect of the unperturbed hot electron and cold electron number density imbalance μ on the onset of the MI is analyzed. Although both dark and bright excitations are obtained, the trend is in contrast to our earlier observations. Our results should be of relevance in wave propagation stability. Nonthermal nonextensive models may play an increasingly important role in predicting complex plasma behavior, and understanding the underlying physical processes.