Exact solutions of a model for strange stars with interacting quarks

The search for the true ground state of dense matter has remained open since Edward Witten proposed the strange matter hypothesis in 1984. In this hypothesis, the strange matter is assumed to be composed of u, d, and s quarks, having an energy per baryon lower than that of quark matter (only u and d), and even lower than that of the nuclear matter. In this sense, neutron stars would be strange stars. Later work showed that a color‐flavor‐locked (CFL) state would be preferred to the one without any pairing for a wide range of the parameters (gap Δ, strange quark mass ms, and bag constant B). We use an approximate, yet very accurate, CFL equation of state (EoS) to obtain exact solutions for the static Einstein field equations that describe a compact relativistic object, providing the first solution directly connected with microphysics.