Charged quark stars in $f(R,T)$ gravity

Abstract

Recent advances in nuclear theory combined with new astrophysical observations have led to the need for specific theoretical models that actually apply to phenomena on dense-matter physics. At the same time, quantum chromodynamics (QCD) predicts the existence of non-nucleonic degrees of freedom at high densities in neutron-star matter, such as quark matter. Within a confining quark matter model, which consists of homogeneous, neutral 3-flavor interacting quark matter with $\mathcal{O}(m_s^4)$ corrections, we study the structure of compact stars made of a charged perfect fluid in the context of $f(R,T)$ gravity. The system of differential equations that describe the structure of charged compact stars have been derived and solved numerically for a gravity model with $f(R,T)=R+2\beta T$. For simplicity, we assume that the charge density is proportional to the energy density, namely, ${\rho }_{\mathrm{ch}}=\alpha \rho$. It is demonstrated that matter-geometry coupling constant $\beta$ and the charge parameter $\alpha$ affect the total gravitational mass and the radius of the star.

Comments: 10 pages, 6 figures. To appear in Chinese Physics C