Compact stars with strongly coupled quark matter in a strong magnetic field

TL;DR

This paper develops an improved quark matter equation of state incorporating magnetic fields, analyzing its impact on the stability and mass-radius relations of compact stars, aligning theoretical models with recent astronomical observations.

Contribution

It introduces a magnetic field into the quark matter EOS and studies its effects on star stability and structure, extending previous models without magnetic fields.

Findings

Magnetic fields influence the stability conditions of quark stars.

Mass-radius relations are significantly affected by magnetic field strength.

Maximum star masses remain above two solar masses with magnetic effects included.

Abstract

Some time ago we have derived from the QCD Lagrangian an equation of state (EOS) for the cold quark matter, which can be considered an improved version of the MIT bag model EOS. Compared to the latter, our equation of state reaches higher values of the pressure at comparable baryon densities. This feature is due to perturbative corrections and also to non-perturbative effects. Later we applied this EOS to the study of compact stars, discussing the absolute stability of quark matter and computing the mass-radius relation for self-bound (strange) stars. We found maximum masses of the sequences with more than two solar masses, in agreement with the recent experimental observations. In the present work we include the magnetic field in the equation of state and study how it changes the stability conditions and the mass-radius curves.