Soliton solutions and interactions of the Zakharov-Kuznetsov equation in the electron-positron-ion plasmas

Analytically investigated in this paper is the Zakharov-Kuznetsov equation which describes the propagation of the electrostatic excitations in the electron-positron-ion plasmas. By means of the Hirota method and symbolic computation, the bilinear form for the Zakharov-Kuznetsov equation is derived, and then the N-soliton solution is constructed. Parametric analysis is carried out in order to illustrate that the soliton amplitude and width are affected by the phase velocity, ion-to-electron density ratio, rotation frequency and cyclotron frequency. Propagation characteristics and interaction behaviors of the solitons are also discussed through the graphical analysis. The effects of the nonlinearity A, dispersion B and disturbed wave velocity C on the amplitude and velocity of the solitons are derived. First, the amplitude is proportional to the nonlinearity A and inversely proportional to dispersion B. Second, the velocity increases as the dispersion B increases. Third, the velocity increases as the disturbed wave velocity C (4B>C) increases; the velocity decreases as the disturbed wave velocity C (4B<C) increases.