Anisotropic quark stars in $R^2$ gravity

TL;DR

This paper investigates how $R^2$ gravity influences the properties and stability of anisotropic quark stars using specific equations of state, revealing potential explanations for super-massive pulsars.

Contribution

It introduces the study of anisotropic quark stars within $R^2$ gravity, analyzing their mass-radius relations and stability, which is a novel approach in modified gravity contexts.

Findings

$R^2$ gravity significantly affects quark star mass-radius relations.

Dynamical stability depends on anisotropic parameters and $a$.

Results suggest possible existence of super-massive pulsars.

Abstract

In the present paper, we treat the problem of the existence of quark stars (QSs) for selected homogeneous and unpaired charge-neutral $3$-flavor interacting quark matter with $\mathcal{O}(m_s^4)$ corrections equations of state (EoS). Using the EoS combined with the Tolmann-Oppenheimer-Volkoff (TOV) structure equations, the properties of stars are explored by obtaining their mass-radius relations. All calculations are carried out within the framework of the $R$-squared gravity defined by $f(R) = R+a R^2$. Our main goal is to discuss the effect for a wide range of the $R$-squared gravity parameter, $a$, on the mass-radius and the mass-central mass density $(M-\epsilon_c)$ relation of QSs. Furthermore, we investigate the dynamical stability condition for those stars, and we show that their dynamical stability depends on the anisotropic parameters $ B_{\perp}$ and $a_4^{\perp}$ coming from the respective EoS. In such a scenario our results provide circumstantial evidence in favor of super-massive pulsars.