Consistent neutron star models with magnetic field dependent equations of state

TL;DR

This paper develops a comprehensive, self-consistent model for neutron star structure that incorporates magnetic field effects on the equation of state, magnetisation, and anisotropies, demonstrating that these factors do not significantly alter maximum mass predictions.

Contribution

It introduces a novel, self-consistent framework for modeling magnetized neutron stars with magnetic field-dependent equations of state, including relativistic and anisotropic effects.

Findings

Magnetic field dependence and magnetisation do not significantly increase maximum neutron star mass.

The model is validated with a quark matter equation of state commonly used in literature.

The approach accounts for anisotropies and relativistic effects in a unified manner.

Abstract

We present a self-consistent model for the study of the structure of a neutron star in strong magnetic fields. Starting from a microscopic Lagrangian, this model includes the effect of the magnetic field on the equation of state, the interaction of the electromagnetic field with matter (magnetisation), and anisotropies in the energy-momentum tensor, as well as general relativistic aspects. We build numerical axisymmetric stationary models and show the applicability of the approach with one example quark matter equation of state (EoS) often employed in the recent literature for studies of strongly magnetised neutron stars. For this EoS, the effect of inclusion of magnetic field dependence or the magnetisation do not increase the maximum mass significantly in contrast to what has been claimed by previous studies.