Modulational instability of electron-acoustic waves in a plasma with a q-nonextensive electron velocity distribution

The amplitude modulation of electron-acoustic waves (EAWs) propagating in space plasmas whose constituents are inertial cold electrons, hot nonextensive q-distributed electrons, and stationary ions is presented theoretically. The nonlinear Schrodinger equation (NLSE) which governs the modulational instability of the EAWs is obtained using reductive perturbation method (RPM). The presence of the hot nonextensive q-distributed electrons is shown to influence the modulational instability of the waves. Further, the nondimensional parameter alpha = n(e0)/n(c0), which is the equilibrium density ratio of the hot to cold electron component, is shown to play a vital role in the formation of both bright and dark solitons. (C) 2011 Elsevier B.V. All rights reserved.