Rapidly Spinning Compact Stars with Deconfinement Phase Transition

• Published in: arXiv.org 2020-09
• Main Authors: Tuna Demircik, Ecker, Christian, Järvinen, Matti
• Format: Article
• Language: English
• Subjects: Equations of state; Neutron stars; Nuclear matter; Phase transitions; Quarks; Stellar rotation
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2009.10731

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, which allow purely hadronic uniformly rotating stars with masses up to approximately \(2.9\, \mathrm{M}_\odot\), and are therefore compatible with the interpretation that the secondary component (\(2.59^{+0.08}_{-0.09}\, \mathrm{M}_\odot\)) in GW190814 is a neutron star. These stars have central densities 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 \(M_{\mathrm{TOV}}\) (\(M_{\mathrm{max}}\)) is either determined by the secular instability or a phase transition induced collapse. We find largest values for \(M_{\mathrm{max}}/M_{\mathrm{TOV}}\) in cases where the phase transition determines \(M_{\mathrm{max}}\), which shifts our fit result to \(M_{\mathrm{max}}/M_{\mathrm{TOV}} = 1.227^{+0.031}_{-0.016}\), a value slightly above the Breu-Rezzolla bound \(1.203^{+0.022}_{-0.022}\) inferred from models without phase transition.