Wave breaking amplitudes of Langmuir modes in electron-positron-ion-dusty plasmas

Abstract

In contrast to the conventional studies on low frequency dust acoustic or dust ion acoustic waves, the investigation is done here on the wave characteristics of high frequency Langmuir modes in electron-positron-ion-dusty plasmas. In the wave analysis, the electrons, positrons, and ions are considered to follow relativistic dynamics. Whereas negative or positive polarity massive dust grains form a fixed charge neutralizing background. Within the Sagdeev pseudopotential approach, the wave breaking amplitudes of such high frequency oscillations are derived. The wave breaking amplitudes are shown to depend on various system parameters like equilibrium ion-to-electron density ratio, relativistic Lorentz factor associated with the phase velocity of oscillations, etc. It has been demonstrated that, even though the dust grains do not participate in the wave dynamics, the nature of their charge polarity and the values of equilibrium dust density have profound effects on the wave breaking amplitudes. We expect that the results of our investigation in such dusty plasma medium may have some relevance in the space plasma research.