Holographic QCD in the NICER era

Abstract

We analyze families of hybrid equations of state of cold QCD matter, which combine input from gauge/gravity duality and from various ab initio methods for nuclear matter at low density, and predict that all neutron stars are fully hadronic without quark matter cores. We focus on constraints from recent measurements by the NICER telescope on the radius and mass of the millisecond pulsar PSR J0740+6620. These results are found to be consistent with our approach: they set only mild constraints on the hybrid equations of state, and favor the most natural models which are relatively stiff at low density. Adding an upper bound on the maximal mass of neutron stars, as suggested by the analysis of the GW170817 neutron star merger event, tightens the constraints considerably. We discuss updated predictions on observables such as the transition density and latent heat of the nuclear to quark matter transition as well as the masses, radii, and tidal deformabilities of neutron stars.

22 pages, 8 figures; v2: refs. added

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Cited by in corpus (7)

• The Present and Future of QCD
• Quark formation and phenomenology in binary neutron-star mergers using V-QCD
• Relativistic hybrid stars with sequential first-order phase transitions in light of multimessenger constraints
• Estimate for the bulk viscosity of strongly coupled quark matter using perturbative QCD and holography
• Holographic cold dense matter constrained by neutron stars
• Normal and Quasinormal Modes of Holographic Multiquark Star
• Chiral Separation Effect from Holographic QCD