Neutron Stars in Scalar Torsion Theories with Nonminimal Coupling

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Kehal, Youcef, Nouicer, Khireddine, Boumaza, Hamza
Natura: Preprint
Pubblicazione: 2023
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866916543875514368
author Kehal, Youcef
Nouicer, Khireddine
Boumaza, Hamza
author_facet Kehal, Youcef
Nouicer, Khireddine
Boumaza, Hamza
contents We study the existence and structure of static and slowly rotating neutron stars (NSs) in a particular truncation of scalar torsion theory with a scalar field $ ϕ$ non-minimally coupled to the torsion scalar, and a potential of the form $ V(ϕ)=-μ^2ϕ^2/2 +λϕ^4 /4 $. We derive the hydrostatic equilibrium equations in the static case and solve them numerically for both interior and exterior regions using the appropriate boundary conditions near the center and far from the star. We plot the radial profiles of the metric functions and the scalar field as well as the mass-radius diagram of the star employing a set of four different realistic equations of state (EoS). Our findings show a high degree of compatibility with the observational constraints of the GW170817 event and indicate a maximum mass $2.37M_{\odot}$ obtained with the BSk21 EoS for a coupling parameter $ ξ=0.25 $. We extend our analysis to include slow rotation, and determine the relation between the star's moment of inertia and its mass. We also show that the universality relation of the two forms of the normalized moment of inertia continue to hold in scalar torsion theory with non minimal coupling.
format Preprint
id arxiv_https___arxiv_org_abs_2305_12155
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Neutron Stars in Scalar Torsion Theories with Nonminimal Coupling
Kehal, Youcef
Nouicer, Khireddine
Boumaza, Hamza
General Relativity and Quantum Cosmology
85-08, 85-10
We study the existence and structure of static and slowly rotating neutron stars (NSs) in a particular truncation of scalar torsion theory with a scalar field $ ϕ$ non-minimally coupled to the torsion scalar, and a potential of the form $ V(ϕ)=-μ^2ϕ^2/2 +λϕ^4 /4 $. We derive the hydrostatic equilibrium equations in the static case and solve them numerically for both interior and exterior regions using the appropriate boundary conditions near the center and far from the star. We plot the radial profiles of the metric functions and the scalar field as well as the mass-radius diagram of the star employing a set of four different realistic equations of state (EoS). Our findings show a high degree of compatibility with the observational constraints of the GW170817 event and indicate a maximum mass $2.37M_{\odot}$ obtained with the BSk21 EoS for a coupling parameter $ ξ=0.25 $. We extend our analysis to include slow rotation, and determine the relation between the star's moment of inertia and its mass. We also show that the universality relation of the two forms of the normalized moment of inertia continue to hold in scalar torsion theory with non minimal coupling.
title Neutron Stars in Scalar Torsion Theories with Nonminimal Coupling
topic General Relativity and Quantum Cosmology
85-08, 85-10
url https://arxiv.org/abs/2305.12155