Planar and Nonplanar Electron-Acoustic Solitary Waves in the Presence of Positrons

Abstract

The propagation of planar and nonplanar electron-acoustic waves composed of stationary ions, cold electrons, superthermal hot electrons, and positrons is studied by using Korteweg–de Vries (KdV) equation in the planar and nonplanar coordinates. The analytical and numerical solutions of KdV equation reveal that the nonplanar electron-acoustic solitons are modified significantly with positron concentration and behave differently in different geometries. It is found that the positron concentration β and positron temperature σ have a negative effect on the wave potential and width of the wave, there is a decrease in the amplitude as well as width of the wave. Thus, it is noticed that the strength of the wave decreases with the growing values of β and σ. From the examination, it is discovered that this increase in height and steepness is more articulated in the spherical geometry than in the cylindrical one. The strength of the wave grows with increment of superthermal particles (low value of κ). There is also an increase in the width of the solitary wave with decreasing the value of κ, which is in agreement with the results of [1]. Further, it is noticed that the spherical wave moves faster than cylindrical waves. This difference arises due to the presence of the geometry term $$m{\text{/}}2\tau $$ , whose value becomes zero in the planar case ( $$m = 0$$ ), $$1{\text{/}}(2\tau )$$ in the cylindrical and $$2{\text{/}}2\tau $$ in the spherical case. Results of our work may be helpful in analyses of the physical behaviour of solitary waves features in different astrophysical and space environments like the supernovas, polar regions and in the vicinity of black holes.