Modulation instability of ion acoustic waves, solitons, and their interactions in nonthermal electron-positron-ion plasmas

Abstract

The propagation of ion acoustic waves in plasmas composed of ions, positrons, and nonthermally distributed electrons is investigated. By means of the reduction perturbation technique, a nonlinear Schrödinger equation is derived and the modulation instability of ion acoustic wave is analyzed, where the nonthermal parameter is found to be of significant importance. Furthermore, analytical expressions for the bright and dark solitons are obtained, and the interaction of multiple solitons is discussed.