The role of strangeness in hybrid stars and possible observables

TL;DR

This paper investigates how strangeness influences the properties and phase transitions of hybrid stars, revealing that significant strangeness can lead to twin-star solutions with identical masses but different radii.

Contribution

It introduces a unified model to study strangeness effects on both hadronic and quark matter in hybrid stars, analyzing phase transitions and global star properties.

Findings

Large strangeness content leads to twin-star solutions.

Strangeness affects the nature of phase transitions.

Hyperons and quarks jointly influence star mass and radius.

Abstract

We study the effects of strangeness on the quark sector of a hybrid star equation of state. Since the model we use to describe quarks is the same as the one we use to describe hadrons, we can also study the effects of strangeness on the chiral symmetry restoration and deconfinement phase transitions (first order or crossover). Finally, we analyze combined effects of hyperons and quarks on global properties of hybrid stars, like mass, radius and cooling profiles. It is found that a large amount of strangeness in the core is related to the generation of twin-star solutions, which can have the same mass as the lower or zero strangeness counterpart, but with smaller radii.