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Quantifying uncertainties and correlations in the nuclear-matter equation of state

Authors :
C. Drischler
Richard Furnstahl
J. A. Melendez
Daniel R. Phillips
Publication Year :
2020
Publisher :
arXiv, 2020.

Abstract

We perform statistically rigorous uncertainty quantification (UQ) for chiral effective field theory ($\chi$EFT) applied to infinite nuclear matter up to twice nuclear saturation density. The equation of state (EOS) is based on high-order many-body perturbation theory calculations with nucleon-nucleon and three-nucleon interactions up to fourth order in the $\chi$EFT expansion. From these calculations our newly developed Bayesian machine-learning approach extracts the size and smoothness properties of the correlated EFT truncation error. We then propose a novel extension that uses multitask machine learning to reveal correlations between the EOS at different proton fractions. The inferred in-medium $\chi$EFT breakdown scale in pure neutron matter and symmetric nuclear matter is consistent with that from free-space nucleon-nucleon scattering. These significant advances allow us to provide posterior distributions for the nuclear saturation point and propagate theoretical uncertainties to derived quantities: the pressure and incompressibility of symmetric nuclear matter, the nuclear symmetry energy, and its derivative. Our results, which are validated by statistical diagnostics, demonstrate that an understanding of truncation-error correlations between different densities and different observables is crucial for reliable UQ. The methods developed here are publicly available as annotated Jupyter notebooks.<br />Comment: 23 pages, 21 figures, 4 tables, supplemental material; close to the published version; minor corrections and additional table summarizing the main results; Jupyter notebooks for reproducing the results and figures can be found at https://buqeye.github.io/software/

Details

Database :
OpenAIRE
Accession number :
edsair.doi.dedup.....3ba4cc578b2f6ba13571f6a8306332f5
Full Text :
https://doi.org/10.48550/arxiv.2004.07805