Rapidly Spinning Compact Stars with Deconfinement Phase Transition

Abstract

We study rapidly spinning compact stars with equations of state featuring a first-order phase transition between strongly coupled nuclear matter and deconfined quark matter by employing the gauge/gravity duality. We consider a family of models that allow purely hadronic uniformly rotating stars with masses up to approximately 2.9 M ⊙ , and are therefore compatible with the interpretation that the secondary component ( ) in GW190814 is a neutron star. These stars have central densities that are several times the nuclear saturation density, so that strong coupling and non-perturbative effects become crucial. We construct models where the maximal mass of static (rotating) stars M TOV ( M max ) is either determined by the secular instability or a phase-transition induced collapse. We find the largest values for M max / M TOV in cases where the phase transition determines M max , which shifts our fit result to , a value slightly above the Breu–Rezzolla bound inferred from models without phase transition.