How well do we know the neutron-matter equation of state at the densities inside neutron stars? A Bayesian approach with correlated uncertainties. (arXiv:2004.07232v1 [nucl-th])

How well do we know the neutron-matter equation of state at the densities inside neutron stars? A Bayesian approach with correlated uncertainties. (arXiv:2004.07232v1 [nucl-th])
<a href="http://arxiv.org/find/nucl-th/1/au:+Drischler_C/0/1/0/all/0/1">C. Drischler</a>, <a href="http://arxiv.org/find/nucl-th/1/au:+Furnstahl_R/0/1/0/all/0/1">R. J. Furnstahl</a>, <a href="http://arxiv.org/find/nucl-th/1/au:+Melendez_J/0/1/0/all/0/1">J. A. Melendez</a>, <a href="http://arxiv.org/find/nucl-th/1/au:+Phillips_D/0/1/0/all/0/1">D. R. Phillips</a>

We introduce a new framework for quantifying correlated uncertainties of the
infinite-matter equation of state (EOS) derived from chiral effective field
theory ($chi$EFT). Bayesian machine learning, via Gaussian Processes with
physics-based hyperparameters, allows us to efficiently quantify and propagate
theoretical uncertainties of the EOS, such as $chi$EFT truncation errors, to
derived quantities. We apply this framework to state-of-the-art many-body
perturbation theory calculations with consistent nucleon-nucleon and
three-nucleon interactions up to fourth order in the $chi$EFT expansion. This
produces the first statistically meaningful uncertainty estimates for key
quantities of neutron stars. We give results up to twice nuclear saturation
density for the energy per particle, pressure, and speed of sound of neutron
matter, as well as for the nuclear symmetry energy and its derivative. At
nuclear saturation density the predicted symmetry energy and its slope are
consistent with experimental constraints.

We introduce a new framework for quantifying correlated uncertainties of the
infinite-matter equation of state (EOS) derived from chiral effective field
theory ($chi$EFT). Bayesian machine learning, via Gaussian Processes with
physics-based hyperparameters, allows us to efficiently quantify and propagate
theoretical uncertainties of the EOS, such as $chi$EFT truncation errors, to
derived quantities. We apply this framework to state-of-the-art many-body
perturbation theory calculations with consistent nucleon-nucleon and
three-nucleon interactions up to fourth order in the $chi$EFT expansion. This
produces the first statistically meaningful uncertainty estimates for key
quantities of neutron stars. We give results up to twice nuclear saturation
density for the energy per particle, pressure, and speed of sound of neutron
matter, as well as for the nuclear symmetry energy and its derivative. At
nuclear saturation density the predicted symmetry energy and its slope are
consistent with experimental constraints.

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