Work

Astrophysics Equation of State Inference with Bayesian Chiral Effective Field Theory Uncertainties

Year: 2026

Type: article

Abstract: We investigate Bayesian chiral effective field theory ( χ EFT) uncertainties, which assign a statistical interpretation to equation of state (EOS) distributions near nuclear saturation density, n 0 , as well as constraints from perturbative quantum chromodynamics (pQCD) to Bayesian EOS inference from LIGO/Virgo, NICER, and pulsar mass observations. The tails of the χ EFT uncertainties allow for broader pressure ranges in our priors, but large parts of these are excluded by the astrophysical observations so that the EOS and the resulting mass–radius posteriors are still very consistent with our earlier work. Within our broad prior ranges, we observe a clear stiffening of the EOS at n ≳ 3 n 0 . Moreover, the impact of the pQCD constraints on the posterior EOS and mass–radius range is negligible due to the astrophysics constraints. Exploiting the strong correlation between pure neutron matter and matter in beta equilibrium, we infer the symmetry energy slope parameter L from astrophysics. For the 68% credible interval, we obtain L = 42.6–52 MeV and L = 44.2–56.7 MeV using piecewise-polytrope and speed-of-sound high-density extensions, respectively. The L posterior is mainly driven by the combination of GW170817 LIGO/Virgo and PSR J0740+6620, PSR J0437-4715, and PSR J0614-3329 NICER observations.

Source: The Astrophysical Journal

DOI: 10.3847/1538-4357/ae92f9