Assessing the joint effect of temperature and magnetic field on the neutron star equation of state

In this work, we study the effect of strong magnetic fields on the equation of state (EoS) of warm, homogeneous, neutron star (NS) matter in beta equilibrium. NS matter is described within a relativistic mean field (RMF) approximation, including both models with nonlinear meson terms or with density-dependent nucleon-meson couplings. We first study the effect of magnetic fields and finite temperature on the EoS separately, finding that the effect of the latter to be significantly stronger than the one of the former. We then study the combined effect of magnetic fields and temperature on the internal composition. We show how both factors cause an increase in the proton fraction at low density and that, as long as the temperatures considered are not higher than 10 MeV, the effect of the magnetic field on the proton fraction is not small enough to be neglected.