Relativistic parameterizations of neutron matter and implications for neutron stars
| Autor: | Jürgen Schaffner-Bielich, Nadine Hornick, Laura Tolos, Andreas Zacchi, Jan-Erik Christian |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Physics
High Energy Astrophysical Phenomena (astro-ph.HE) Particle physics Nuclear Theory media_common.quotation_subject Isoscalar Astrophysics::High Energy Astrophysical Phenomena FOS: Physical sciences 01 natural sciences Asymmetry Nuclear Theory (nucl-th) Neutron star Effective mass (solid-state physics) Pulsar 0103 physical sciences Effective field theory Neutron Astrophysics::Earth and Planetary Astrophysics 010306 general physics Astrophysics - High Energy Astrophysical Phenomena 010303 astronomy & astrophysics Nuclear theory media_common |
| Popis: | We construct parameter sets of the relativistic mean-field model fitted to the recent constraints on the asymmetry energy $J$ and the slope parameter $L$ for pure neutron matter. We find cases of unphysical behaviour, i.e.\ the appearance of negative pressures, for stiff parameter sets with low values of the effective mass $m^*/m$. In some cases the equation of state of pure neutron matter turns out to be outside the allowed band given by chiral effective field theory. The mass-radius relations of neutron stars for all acceptable parameter sets shows a maximum mass in excess of $2M_\odot$ being compatible with pulsar mass measurements. Given the constraints on the model in the low-density regime coming from chiral effective theory, we find that the radius of a $1.4M_\odot$ neutron star is nearly independent on the value of $L$. This is in contrast to some previous claims for a strong connection of the slope parameter with the radius of a neutron star. In fact, the mass-radius relation turns out to depend only on the isoscalar parameters of symmetric matter. The constraints of GW170817 on the tidal deformability and on the radius are also discussed. 11 pages, 7 figures |
| Databáze: | OpenAIRE |
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