DOI: 10.5281/zenodo.17024839
title: EOS tables from Bayesian inference favoring quark matter in neutron star interiors (arXiv:2509.02554)

description: This dataset accompanies the manuscript:Alexander Ayriyan, Oleksii Ivanytskyi, David Blaschke. Bayesian inference favors quark matter in neutron star interiors (arXiv:2509.02554 [nucl-th]).

It provides tabulated hybrid Equations of State (EOS) for neutron star matter, combining the density-dependent relativistic functional DD2Y-T (including hyperonic degrees of freedom) with color-flavor-locked quark matter modeled by a three-flavor nonlocal Nambu–Jona-Lasinio framework that incorporates vector repulsion and diquark pairing.

Bayesian analysis and constraint setsThe Bayesian analysis explores the EOS parameter space characterized by the coupling constants $\eta_D$ (diquark interaction) and $\eta_V$ (vector interaction).Two different scenarios of neutron-star mass–radius (M–R) constraints were applied:1. Basic set: includes all currently available NICER M–R constraints together with the tidal deformability constraint from GW170817. Specifically, it contains: - PSR J0030+0451 ($M = 1.44^{+0.15}_{-0.14},M_\odot$, $R = 13.02^{+1.24}_{-1.06}$ km; Miller et al. ApJL 2019), - PSR J0740+6620 ($M = 2.08 \pm 0.07,M_\odot$, $R = 12.92^{+2.09}_{-1.13}$ km; Dittmann et al. ApJ 2024), - PSR J0437–4715 ($M = 1.418 \pm 0.037,M_\odot$, $R = 11.36^{+0.95}_{-0.63}$ km; Choudhury et al. ApJL 2024), - PSR J0614–3329 ($M = 1.44^{+0.06}_{-0.07},M_\odot$, $R = 10.29^{+1.01}_{-0.86}$ km; Mauviard et al. arXiv:2506.14883 2025), - GW170817 tidal deformability (Abbott et al. PRL 2018).

2. Full set: extends the basic set by including two further constraints: - PSR J0952–0607 (“black widow” pulsar), providing a lower bound on the maximum mass ($M = 2.35 \pm 0.17,M_\odot$; Romani et al. ApJL 2022). A correction for rapid rotation was applied, reducing the mass estimate by about 5%. - HESS J1731–347 ($M = 0.77^{+0.20}_{-0.17},M_\odot$, $R = 10.04^{+0.86}_{-0.78}$ km; Doroshenko et al. Nature Astron. 2022).

EOS tablesThe dataset includes EOS tables for representative parameter sets selected from the 60% Bayesian credibility region, covering physically relevant cases (see BA_DD2Y_3FNJL_etaD-etaV_full.png), such as: - the most probable EOS (basic set), - the EOS yielding the highest maximum neutron-star mass (basic set), - the EOS yielding the highest maximum mass among all EOS with a third-family branch (basic set), - the EOS yielding the lowest possible maximum neutron-star mass (basic set), - the most probable EOS according to the full set.

This collection enables further exploration of neutron-star properties and enhances the transparency and reproducibility of the published results.

Data Description1. EOS TablesEach file corresponds to a particular parameter set (see the attached figure 'pressure_vs_energy_density.png'). Filenames follow the convention: DD2Y_3FNJL_etaV=<$\eta_V$>_etaD=<$\eta_D$>.datEach file contains the following columns: - mu_B - baryon chemical potential [MeV] - p - pressure [MeV/fm³] - n_B - baryon density [1/fm³] - eps - energy density [MeV/fm³] - cs2 - squared speed of sound [c²]

2. Contour tablesThere are four files containing the 60% and 90% Bayesian credibility regions on the $\eta_D$–$\eta_V$ plane, provided separately for the basic set and the full set of mass–radius constraints: - DD2Y_3FNJL_etaD_etaV_contour_60_basic_set.dat - DD2Y_3FNJL_etaD_etaV_contour_90_basic_set.dat - DD2Y_3FNJL_etaD_etaV_contour_60_full_set.dat - DD2Y_3FNJL_etaD_etaV_contour_90_full_set.datFile format: - Column 1: $\eta_D$ - Column 2: $\eta_V$