# Constructing a neutron star in G2-QCD

## TL;DR

This study explores the internal structure of neutron stars within a modified QCD framework based on the G2 gauge group, revealing how gauge interactions influence their mass-radius relation and internal phases.

## Contribution

It introduces a lattice-based equation of state for G2-QCD and analyzes its impact on neutron star structure, providing new insights into gauge interaction effects.

## Key findings

- Gauge interactions affect the neutron star mass-radius relation.
- Quark mass has minimal impact on the star's structure.
- Density profiles and phase structures inside the star are characterized.

## Abstract

The inner structure of neutron stars is still an open question. To make progress and understand the qualitative impact of gauge interactions on the neutron star structure we study neutron stars in a modified version of QCD. In this modification the gauge group of QCD is replaced by the exceptional Lie group G$_2$, which has neutrons and is accessible at finite density in lattice calculations. Using an equation of state constructed from lattice calculations we determine the mass-radius-relation for a neutron star in this theory using the Tolman-Oppenheimer-Volkoff equation. The results exhibit an influence of the non-trivial interactions on the mass-radius relation. However, the masses of the quarks are found to have little influence. We also give density profiles and the phase structure inside the neutron star. If the results carry over to full QCD, much of the internal structure of neutron stars could already be inferred from a precise measurement of the mass-radius relation.