On the MHD simple waves in fully relativistic electron-positron plasmas with radiation

The one dimensional propagation of simple waves in the system of electron-positron and photon gas at relativistic temperatures is considered. The presence of the transverse (across the wave propagation direction) velocity will change the dependencies of the phase velocity and magnetosound velocity upon temperature essentially. It is shown that at the presence of transverse velocity, the decrease of these characteristic velocities of simple wave takes place, while the time of shock wave formation becomes shorter.