English

Astrophysics equation of state inference with Bayesian chiral effective field theory uncertainties

Nuclear Theory 2026-05-19 v1 High Energy Astrophysical Phenomena

Abstract

We investigate Bayesian chiral effective field theory (χ\chiEFT) uncertainties, which assign a statistical interpretation to equation of state (EOS) distributions near nuclear saturation density, n0_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\chiEFT 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 n3n0n \gtrsim 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 LL from astrophysics. For the 68%68\% credible interval, we obtain L=42.652L=42.6-52 MeV and L=44.256.7L=44.2-56.7 MeV using piecewise-polytrope and speed-of-sound high-density extensions, respectively. The LL posterior is mainly driven by the combination of GW170817 LIGO/Virgo and PSR J0740+6620, PSR J0437-4715, and PSR J0614-3329 NICER observations.

Keywords

Cite

@article{arxiv.2605.18560,
  title  = {Astrophysics equation of state inference with Bayesian chiral effective field theory uncertainties},
  author = {Melissa Mendes and Hannah Göttling and Anna Hensel and Isak Svensson and Kai Hebeler and Achim Schwenk and Nathan Rutherford and Anna Watts},
  journal= {arXiv preprint arXiv:2605.18560},
  year   = {2026}
}

Comments

14 pages, 10 figures. Comments welcome