https://doi.org/10.1140/epja/s10050-024-01309-3
Regular Article - Theoretical Physics
Effects of dilute neutron matter on the neutron star crust equation of state
1
Institut d’Astronomie et d’Astrophysique, CP-226, Université Libre de Bruxelles, 1050, Brussels, Belgium
2
Institut de Physique des 2 infinis de Lyon, CNRS/IN2P3, Université de Lyon, Université Claude Bernard Lyon 1, 69622, Villeurbanne Cedex, France
3
International Research Laboratory on Nuclear Physics and Astrophysics, Michigan State University and CNRS, 48824, East Lansing, MI, USA
Received:
30
January
2024
Accepted:
22
March
2024
Published online:
23
April
2024
We develop a compressible liquid-drop model to describe the crust of neutron stars for which the role of the nuclear clusters, the neutron gas, and the electrons are clearly identified. The novelty relies on the contribution of the neutron gas, which is qualitatively adjusted to reproduce ‘ab initio’ predictions in dilute neutron matter. We relate the properties of dilute neutron matter to the ones of neutron stars crust and we compare the mean-field approximation to an improved approach that better describes dilute neutron matter1. The latter is quite sensitive to the unitary limit, a universal feature of Fermi systems having a large value of the scattering length and a small interaction range. While the impact of the accurate description of dilute neutron matter is important in uniform matter (up to 30% corrections with respect to a mean-field calculations), we find a reduction of this impact in the context of the crust of neutron stars due to the additional matter components (nuclear clusters and electrons). In agreement with our previous works, dilute neutron matter is however a necessary ingredient for accurate predictions of the properties of the crust of neutron stars.
Supplementary Information The online version contains supplementary material available at https://doi.org/10.1140/epja/s10050-024-01309-3.
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© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2024. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.