Abstract
The higher-order (H-O) phase shift of dust ion-acoustic solitons (DIASs) in a weakly relativistic plasma is examined considering the influence of both superthermality-distributed electrons and positrons. Employing the extended Poincare-Lighthill-Kuo method (EPLKM), the Korteweg-de Vries equations (KdVEs) and the deviation in trajectories of DIASs (i.e., phase shifts) are obtained after the collision. For obtaining H-O phase shifts of DIASs, the fifth-order dispersion terms are added into KdVEs. The effects of the relativistic factor for a weakly relativistic regime and the superthermality of both electrons and positrons on the H-O phase shifts are discussed. Numerical analysis gives rise to important highlights on the excitation and the collision of DIASs in astrophysical situations such as a pulsar magnetosphere.