Energy of nonlinear electron acoustic solitons in electron positron ion plasma

A rigorous theoretical investigation is made to find energy of EASWs in unmagnetized collisionless plasma having stationary ions, cold electrons, hot electrons and hot positrons. By employing reductive perturbation method KdV equation is derived and solution of KdV equation is proposed by homotopy perturbation method (HPM) in two cases, i.e. in kappa distribution and in Cairns distribution. The consequences of different parameters variation on soliton profile have been studied. It is noticed amplitude and width of soliton are sensitive to k (spectral index of kappa distributed populations) i.e. increasing k makes an increase in soliton amplitude and width. It is also found dip and hump type solitons exist due to presence of electrons and positrons and σ=Te/TP affects the dip and hump type solitons profile. Also we found energy of soliton in kappa distribution and in Cairns distribution. This work may be helpful for astronomers and space investigators, working on planetary magneto spheres, earth's ionosphere auroral zone, and interstellar space plasmas etc.