Quark stars in the Einstein–Gauss–Bonnet theory: A new branch of stellar configurations

Abstract

The observations of pulsars heavier than 2M⊙ have put strong constraints on the equation of state (EoS) above nuclear saturation density. For this reason, the internal structure of a neutron star which is strictly correlated with the EoS is an active area of investigation in theoretical astrophysics. Here, we investigate the possible sequels for the quark stars consisting of a homogeneous and unpaired charge-neutral 3-flavor interacting quark matter with O(ms4) corrections that accounts for the quark strong interactions. In particular, the quark stars (QSs) with a well-motivated quantum chromodynamics (QCD) EoS are presented in Einstein gravity with the Gauss–Bonnet (GB) combination of quadratic curvature terms. We analyze the dependence of the physical properties of these QSs on the Gauss–Bonnet coupling strength. In fact, the existence and stability of QSs depend on the effects of fourth-order corrections parameter (a4) of the QCD perturbation. We also present and discuss the calculated results for mass–central mass density (M–ρc) relation and also the mass–radius (M–R) relation of QSs. Nevertheless, such deviations may be observable in future astrophysical probes.