RELATIVISTIC-MAGNETOHYDRODYNAMICS EQUATIONS AND EQUATORIAL RADIAL MOTION IN THE MAGNETIZED SCHWARZSCHILD SPACE-TIME

Relativistic-magnetohydrodynamics equations resulting from the interaction of perfect fluids (non-polarizable) with electromagnetic field are reviewed and presented in a form suitable for numerical studies. As a particular case, the equatorial radial motion in the magnetized Schwarzschild space-time is investigated: specifically, the effects of the magnetic field in the coordinate velocity, density and four-velocity. Two cases are considered. The radial geodesic infall (pressure neglected) and the radial accretion (including pressure) of a polytropic gas. Also, we have found the location of the critical points where hydromagnetic flows go from a subsonic to a supersonic regime.