Stiff equation of state for a holographic nuclear matter as instanton gas

TL;DR

This paper models nuclear matter using a holographic instanton gas to derive its equation of state and applies it to analyze the structure of cold compact stars, revealing similarities to quark stars.

Contribution

It introduces a holographic instanton gas model to compute the nuclear matter equation of state and explores its implications for cold star configurations.

Findings

The equation of state is derived at low temperature.

The mass-radius relation resembles that of quark stars.

The instanton gas acts as a form of self-bound matter.

Abstract

In a holographic model, which was used to investigate the color superconducting phase of QCD, a dilute gas of instantons is introduced to study the nuclear matter. The free energy of the nuclear matter is computed as a function of the baryon chemical potential in the probe approximation. Then the equation of state is obtained at low temperature. Using the equation of state for the nuclear matter, the Tolman-Oppenheimer-Volkov equations for a cold compact star are solved. We find the mass-radius relation of the star, which is similar to the one for quark star. This similarity implies that the instanton gas given here is a kind of self-bound matter.