The Effects of Superhigh Magnetic Fields on Equations of States of Neutron Stars

TL;DR

This paper investigates how superhigh magnetic fields influence the equations of state of neutron stars, revealing increased electron pressure, potential shape deformation, and higher maximum mass for magnetars due to magnetic effects.

Contribution

It introduces a new formula for electron pressure under superhigh magnetic fields and explores the impact of magnetic fields on neutron star structure and mass.

Findings

Electron pressure increases with magnetic field strength.

Magnetars may be more oblate and compact than typical pulsars.

Maximum mass of magnetars could be higher due to magnetic energy contributions.

Abstract

By introducing Dirac ?-function in superhigh magnetic field, we deduce a general formula for pressure of degenerate and relativistic electrons, Pe, which is suitable for superhigh magnetic fields, discuss the quantization of Landau levels of electrons, and consider the quantum electrodynamic(QED) effects on the equations of states (EOSs) for different matter systems. The main conclusions are as follows: the stronger the magnetic field strength, the higher the electron pressure becomes; compared with a common radio pulsar, a magnetar could be a more compact oblate spheroid-like deformed neutron star due to the anisotropic total pressure; and an increase in the maximum mass of a magnetar is expected because of the positive contribution of the magnetic field energy to the EOS of the star. Since this is an original work in which some uncertainties could exist, to further modify and perfect our theory model should be considered in our future studies.