Boson stars: Chemical potential and quark condensates

TL;DR

This paper investigates how chemical potential influences the structure and properties of boson stars, including those made of quark condensates, revealing significant effects on their maximum mass, radius, and formation conditions.

Contribution

It introduces a generalized TOV equation incorporating chemical potential effects and explores new solutions for boson stars, especially in the context of quark condensates.

Findings

Maximum mass and radius of boson stars are significantly affected by chemical potential.

Quark-condensate boson stars are unlikely at high densities but may form at low densities and high pressures.

Finite chemical potential alters the density and pressure regimes for boson star formation.

Abstract

We study the properties of a star made of self-gravitating bosons gas in a mean-field approximation. A generalized set of Tolman-Oppenheimer-Volkov(TOV) equations is derived to incorporate the effect of chemical-potential in the general relativistic frame work. The metric-dependence of the chemical-potential gives a new class of solutions for the boson stars. It is demonstrated that the maximum mass and radius of the star change in a significant way when the effect of finite chemical-potential is considered. We also discuss the case of a boson star made of quark-condensates. It is found that when the self-interaction between the condensates is small as compared to their mass, the typical density is too high to form a diquark-boson star. Our results indicate that the star of quark-condensate may be formed in a low-density and high-pressure regime.