The Equation of State of Neutron-Rich Matter at Fourth Order of Chiral Effective Field Theory and the Radius of a Medium-Mass Neutron Star
We report neutron star predictions based on our most recent equations of state. These are derived from chiral effective field theory, which allows for a systematic development of nuclear forces, order by order. We utilize high-quality two-nucleon interactions and include all three-nucleon forces up...
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MDPI AG
2022-02-01
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| Online Access: | https://www.mdpi.com/2218-1997/8/2/133 |
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| author | Francesca Sammarruca Randy Millerson |
| author_facet | Francesca Sammarruca Randy Millerson |
| author_sort | Francesca Sammarruca |
| collection | DOAJ |
| description | We report neutron star predictions based on our most recent equations of state. These are derived from chiral effective field theory, which allows for a systematic development of nuclear forces, order by order. We utilize high-quality two-nucleon interactions and include all three-nucleon forces up to fourth order in the chiral expansion. Our <i>ab initio</i> predictions are restricted to the domain of applicability of chiral effective field theory. However, stellar matter in the interior of neutron stars can be up to several times denser than normal nuclear matter at saturation, and its composition is essentially unknown. Following established practices, we extend our microscopic predictions to higher densities matching piecewise polytropes. The radius of the average-size neutron star, about 1.4 solar masses, is sensitive to the pressure at normal densities, and thus it is suitable to constrain <i>ab initio</i> theories of the equation of state. For this reason, we focus on the radius of medium-mass stars. We compare our results with other theoretical predictions and recent constraints. |
| first_indexed | 2024-03-09T20:54:47Z |
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| issn | 2218-1997 |
| language | English |
| last_indexed | 2024-03-09T20:54:47Z |
| publishDate | 2022-02-01 |
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| series | Universe |
| spelling | doaj.art-b616abde4b0c43b89433cffd371b63282023-11-23T22:23:59ZengMDPI AGUniverse2218-19972022-02-018213310.3390/universe8020133The Equation of State of Neutron-Rich Matter at Fourth Order of Chiral Effective Field Theory and the Radius of a Medium-Mass Neutron StarFrancesca Sammarruca0Randy Millerson1Physics Department, University of Idaho, Moscow, ID 83844, USAASML, Chandler, AZ 85224, USAWe report neutron star predictions based on our most recent equations of state. These are derived from chiral effective field theory, which allows for a systematic development of nuclear forces, order by order. We utilize high-quality two-nucleon interactions and include all three-nucleon forces up to fourth order in the chiral expansion. Our <i>ab initio</i> predictions are restricted to the domain of applicability of chiral effective field theory. However, stellar matter in the interior of neutron stars can be up to several times denser than normal nuclear matter at saturation, and its composition is essentially unknown. Following established practices, we extend our microscopic predictions to higher densities matching piecewise polytropes. The radius of the average-size neutron star, about 1.4 solar masses, is sensitive to the pressure at normal densities, and thus it is suitable to constrain <i>ab initio</i> theories of the equation of state. For this reason, we focus on the radius of medium-mass stars. We compare our results with other theoretical predictions and recent constraints.https://www.mdpi.com/2218-1997/8/2/133neutron matterequation of stateneutron starsymmetry energychiral effective field theory |
| spellingShingle | Francesca Sammarruca Randy Millerson The Equation of State of Neutron-Rich Matter at Fourth Order of Chiral Effective Field Theory and the Radius of a Medium-Mass Neutron Star Universe neutron matter equation of state neutron star symmetry energy chiral effective field theory |
| title | The Equation of State of Neutron-Rich Matter at Fourth Order of Chiral Effective Field Theory and the Radius of a Medium-Mass Neutron Star |
| title_full | The Equation of State of Neutron-Rich Matter at Fourth Order of Chiral Effective Field Theory and the Radius of a Medium-Mass Neutron Star |
| title_fullStr | The Equation of State of Neutron-Rich Matter at Fourth Order of Chiral Effective Field Theory and the Radius of a Medium-Mass Neutron Star |
| title_full_unstemmed | The Equation of State of Neutron-Rich Matter at Fourth Order of Chiral Effective Field Theory and the Radius of a Medium-Mass Neutron Star |
| title_short | The Equation of State of Neutron-Rich Matter at Fourth Order of Chiral Effective Field Theory and the Radius of a Medium-Mass Neutron Star |
| title_sort | equation of state of neutron rich matter at fourth order of chiral effective field theory and the radius of a medium mass neutron star |
| topic | neutron matter equation of state neutron star symmetry energy chiral effective field theory |
| url | https://www.mdpi.com/2218-1997/8/2/133 |
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