Anisotropic Stars in 4D Einstein-Gauss-Bonnet Gravity

TL;DR

This paper investigates the effects of anisotropy and Gauss-Bonnet gravity on quark star properties, revealing potential explanations for super-massive pulsars within a 4D Einstein-Gauss-Bonnet framework.

Contribution

It introduces a detailed analysis of anisotropic quark stars in 4D Einstein-Gauss-Bonnet gravity, highlighting the impact of GB coupling on star stability and mass-radius relations.

Findings

Gauss-Bonnet coupling influences mass-radius diagrams.

Anisotropy affects star stability and maximum mass.

Results suggest super-massive pulsars can exist in this framework.

Abstract

The current trend concerning dense matter physics at sufficiently high densities and low temperatures is expected to behave as a degenerate Fermi gas of quarks forming Cooper pairs, namely a color superconductor, in the core of compact objects. In this context, we study the anisotropy of quark stars (QSs) assuming the internal composition to be comprised of homogeneous, charge neutral 3-flavor interacting quark matter with $\mathcal{O}(m_s^4)$ corrections. Using the equation of state (EoS) with the Tolmann-Oppenheimer-Volkoff (TOV) structure equations, we perform numerical calculation for quark stars and determine the maximum mass-radius relation in the context of $4D$ Einstein-Gauss-Bonnet (EGB) gravity. In particular, we consider the effects of Gauss-Bonnet (GB) coupling constant on the diagrams related to mass-radius $(M-R)$ relation and the mass-central mass density $(M-\rho_c)$ relation of QSs. We pay particular attention to the influence of the anisotropy in the equilibrium and stability of strange stars. We also study the other properties of QSs related to compactness and binding energy. Interestingly, our result provides circumstantial evidence in favor of super-massive pulsars in $4D$ EGB gravity.