Quark stars in generalized hybrid metric-Palatini gravity

Abstract: We investigate the physical properties of quark stars with two different equations of state in generalized hybrid metric-Palatini gravity. This theory corresponds to a bi-scalar gravitational theory in which there are two non-minimally-coupled scalar fields. The field equations of the metric tensor and scalar fields are derived by varying the action with respect to the dynamical fields. We obtain the field equations for static spherically symmetric geometry interior of compact objects. The numerical solutions for two types of quark stars, the MIT bag and CFL model are studied. The solutions reveal the structure of the compact objects. The solutions are obtained for different values of the model parameters. All considered cases show that compact objects are more massive than their general relativity counterpart. The surface redshift and compactness are also obtained which shows that the generalized hybrid metric-Palatini quark stars have higher surface redshift and are more compact than general relativity quark stars.