Propagation of Compressional Alfv\'en Waves in a Magnetized Pair Plasma Medium

TL;DR

This paper investigates the nonlinear propagation of compressional Alfvén waves in electron-positron plasmas, revealing distinct solitary wave behaviors for fast and slow modes relevant to laboratory and space plasma environments.

Contribution

It applies the reductive perturbation method to derive solitary wave solutions for EP magneto-acoustic modes, highlighting differences between fast and slow wave properties.

Findings

Fast EPMA mode propagates as compressive solitary waves.

Slow EPMA mode propagates as rarefactive solitary waves.

Distinct wave shapes and properties for fast and slow modes.

Abstract

The reductive perturbation approach was used to explore the nonlinear propagation of fast (compressive) and slow (rarefactive) electron-position (EP) magneto-acoustic (EPMA) modes in an EP plasma medium. The solitary wave solution of the Korteweg-de Vries (K-dV) equation is used to identify the basic properties of EP compressional Alfv\'en waves. It is shown that the fast (slow) EPMA mode is predicted to propagate as compressive (rarefactive) solitary waves. The basic features (i.e., speed, amplitude, and width) of the compressive (i.e., fast) EPMA waves are found to be completely different from those of rarefactive (i.e., slow) EPMA ones. It is also examined that hump (dip) shape solitary waves are found for fast (slow) mode. The significance of our findings is in understanding the nonlinear electromagnetic wave phenomena in laboratory plasma and space environments where EP plasma may exist.