Magnetized neutron matter and deformed neutron stars

Abstract

In this work, we study the influences of density-dependent magnetic field on the equation of state (EoS) of neutron matter using the lowest order constraint variational method. We consider the effects of neutron mass reduction due to the strong magnetic field on the EoS and perform our calculations applying magnetic field-dependent neutron mass (MFD model) and magnetic field-independent neutron mass (MFI model). In this paper, the longitudinal and transverse pressures with respect to the direction of magnetic field are calculated. According to our results for longitudinal pressure of magnetized neutron matter, the upper limit of the magnetic field strength in the neutron star is about G. Furthermore, we investigate the structure of deformed neutron stars by solving Einstein equations and expanding the metric up to the quadrupole term in spherical harmonics. The maximum gravitational mass obtained is about 1.79 M⊙ for the MFI model and 1.93 M⊙ for the MFD model. We find that the oblateness of the neutron star increases by enhancing field strength.