Modified Korteweg-de Vries-Zakharov-Kuznetsov solitons in symmetric two-temperature electron-positron plasmas

Solitary waves are investigated in a magnetized electron-positron plasma consisting of equal hot and cool components of each species. The hot components have a Boltzmann distribution and the cool components are described by the fluid equations. A modified Korteweg-de Vries-Zakharov-Kuznetsov equation governing the oblique propagation of nonlinear electrostatic modes is derived using the reductive-perturbation technique. Soliton amplitudes are studied as a function of plasma parameters such as the particle number densities and the temperatures. Such results may be of relevance to the magnetosphere of pulsars.