Anisotropic equation of state of charged and neutral vector boson gases in a constant magnetic field. Astrophysical implications

Abstract

We obtain the pressures and equations of state (EoS) of charged and neutral vector boson gases in a constant magnetic field. The axial symmetry imposed to the system by the field splits the pressures in the parallel and perpendicular directions along the magnetic axis, and this leads to anisotropic equations of state. The values of pressures and energy densities are in the order of those of Fermi gases in compact objects. This opens the possibility to the existence of magnetized boson stars. Under certain conditions, the perpendicular pressure might be negative imposing a bound to the stability of the star. Other implications of negative pressures are also discussed.