Bayesian Inference of Hybrid Neutron Star Equations of State with a Color-Superconducting Quark Core

by Alexander Ayriayan (University of Wrocław)

Friday 23 Jan 2026, 14:00 → 15:00 Europe/Budapest

Tanácsterem (III. ép.)

We investigate observational constraints on the equation of state (EOS) of dense matter within a Bayesian framework, employing recent measurements of neutron star masses, radii, and tidal deformabilities. The study is devoted to hybrid EOS models that allow for the emergence of a color-superconducting quark phase in the interior of neutron stars. The quark matter sector is modeled using a recently developed nonlocal chiral approach, while the hadronic phase is described by a relativistic density functional of the DD2 family. The transition between nuclear and quark matter is implemented via a Maxwell construction. By exploring the two-parameter space spanned by the vector meson interaction strength and the scalar diquark coupling, we determine the region favored by observational data, defined as parameter sets reaching at least 90% of the maximum posterior probability. We further analyze how this preferred region overlaps with domains that realize additional physically motivated conditions, such as the presence of large quark cores in neutron stars, an early onset of quark deconfinement, and the existence of a third family of compact stars.