Properties of Neutron Stars with Hyperons within a Relativistic Metamodel

Fuente: arXiv
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Main Authors: Char, Prasanta, Mondal, Chiranjib, Alezraa, Timothé, Gulminelli, Francesca, Oertel, Micaela
Format: Preprint
Published: 2025
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author Char, Prasanta
Mondal, Chiranjib
Alezraa, Timothé
Gulminelli, Francesca
Oertel, Micaela
author_facet Char, Prasanta
Mondal, Chiranjib
Alezraa, Timothé
Gulminelli, Francesca
Oertel, Micaela
contents In this work, we study the effects of $Λ$-hyperons on neutron star properties employing a metamodel framework for the equation of state (EoS). Different choices for defining the hyperonic couplings with different levels of parametric freedom are discussed. In all models, the predicted NS maximum masses are reduced compared with the purely nucleonic composition as expected. In the case of relating hyperonic couplings via $SU(6)$-symmetry arguments to the nucleonic ones, we find that NS radii for intermediate mass stars are shifted to higher values compared with purely nucleonic stars, in agreement with the existing literature. However, allowing for more freedom for the hyperonic couplings, the effect is strongly reduced, and the distributions in the NS mass-radius plane of models with and without hyperons become very close. We have also investigated how different nucleonic density functionals influence the hyperon matter composition and neutron star properties.
format Preprint
id arxiv_https___arxiv_org_abs_2510_00997
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Properties of Neutron Stars with Hyperons within a Relativistic Metamodel
Char, Prasanta
Mondal, Chiranjib
Alezraa, Timothé
Gulminelli, Francesca
Oertel, Micaela
Nuclear Theory
High Energy Astrophysical Phenomena
In this work, we study the effects of $Λ$-hyperons on neutron star properties employing a metamodel framework for the equation of state (EoS). Different choices for defining the hyperonic couplings with different levels of parametric freedom are discussed. In all models, the predicted NS maximum masses are reduced compared with the purely nucleonic composition as expected. In the case of relating hyperonic couplings via $SU(6)$-symmetry arguments to the nucleonic ones, we find that NS radii for intermediate mass stars are shifted to higher values compared with purely nucleonic stars, in agreement with the existing literature. However, allowing for more freedom for the hyperonic couplings, the effect is strongly reduced, and the distributions in the NS mass-radius plane of models with and without hyperons become very close. We have also investigated how different nucleonic density functionals influence the hyperon matter composition and neutron star properties.
title Properties of Neutron Stars with Hyperons within a Relativistic Metamodel
topic Nuclear Theory
High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2510.00997