On the Characteristics of Magnetosonic Waves in a Spin-Polarized Degenerate Electron-Positron-Ion Plasma

The linear properties of magnetosonic waves are studied by using the separated spin evolution quantum hydrodynamic equations in which each electron and positron are treated as two different fluids. At the perpendicular propagation, we have only one magnetosonic wave which is affected by both spin polarization and concentration of positron. In the case of oblique propagation, we solve dispersion numerically and found that three wave solutions are obtained without taking into account separate spin evolution (SSE), but the oblique propagation with SSE gives five wave solutions, two of them are electron and positron spin-dependent wave solutions and have been reported for the first time. It is noted that the spin polarization and positron concentration reduce the phase velocities of the obliquely propagating spectra. Moreover, it is seen that the obliqueness effect enhances the frequency of all waves. Finally, the comparison with earlier reported results is also presented. For numerical analysis, we choose parameters relevant to astrophysical environments.