Head-on collision between positron acoustic waves in homogeneous and inhomogeneous plasmas

• Published in: Astrophysics and space science 2018-05, Vol.363 (5), p.1-15, Article 102
• Main Authors: Alam, M. S., Hafez, M. G., Talukder, M. R., Ali, M. Hossain
• Format: Article
• Language: English
• Subjects: Acoustic waves; Amplitudes; Astrobiology; Astronomy; Astrophysics; Astrophysics and Astroparticles; Charged particles; Coordinate transformations; Cosmology; Electrons; Evolution; Hot electrons; Mathematical analysis; Nonlinear equations; Nonlinear evolution equations; Observations and Techniques; Original Article; Parameter modification; Perturbation methods; Physics; Physics and Astronomy; Plasmas (physics); Positive ions; Positrons; Rogue waves; Solitary waves; Solitons; Space Exploration and Astronautics; Space Sciences (including Extraterrestrial Physics
• ISSN: 0004-640X; 1572-946X
• DOI: 10.1007/s10509-018-3320-3

The head-on collision between positron acoustic solitary waves (PASWs) as well as the production of rogue waves (RWs) in homogeneous and PASWs in inhomogeneous unmagnetized plasma systems are investigated deriving the nonlinear evolution equations. The plasmas are composed of immobile positive ions, mobile cold and hot positrons, and hot electrons, where the hot positrons and hot electrons are assumed to follow the Kappa distributions. The evolution equations are derived using the appropriate coordinate transformation and the reductive perturbation technique. The effects of concentrations, kappa parameters of hot electrons and positrons, and temperature ratios on the characteristics of PASWs and RWs are examined. It is found that the kappa parameters and temperature ratios significantly modify phase shifts after head-on collisions and RWs in homogeneous as well as PASWs in inhomogeneous plasmas. The amplitudes of the PASWs in inhomogeneous plasmas are diminished with increasing kappa parameters, concentration and temperature ratios. Further, the amplitudes of RWs are reduced with increasing charged particles concentration, while it enhances with increasing kappa- and temperature parameters. Besides, the compressive and rarefactive solitons are produced at critical densities from KdV equation for hot and cold positrons, while the compressive solitons are only produced from mKdV equation for both in homogeneous and inhomogeneous plasmas.