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Related papers: Neutron Stars in Scalar Torsion Theories with Nonm…

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We study the structure of neutron stars in scalar-tensor theories for the nonminimal coupling of the form $(1+\kappa \xi \phi^{2})\cal R$. We solve the hydrostatic equilibrium equations for two different types of scalar field potentials and…

General Relativity and Quantum Cosmology · Physics 2019-04-02 A. Savaş Arapoğlu , K. Yavuz Ekşi , A. Emrah Yükselci

In this work we investigate the effects of a non-minimally coupled quartic order scalar model on static neutron stars, with the non-minimal coupling in the Jordan frame being of the form $f(\phi ) = 1 + \xi\phi^2$. Particularly we derive…

General Relativity and Quantum Cosmology · Physics 2022-04-13 S. D. Odintsov , V. K. Oikonomou

We investigate equilibrium configurations of uniformly rotating neutron stars in $R^2$ gravity with axion scalar field for GM1 equation of state (EoS) for nuclear matter. The mass-radius diagram, mass-central energy density are presented…

General Relativity and Quantum Cosmology · Physics 2020-09-09 Artyom V. Astashenok , Sergey D. Odintsov

In Horndeski theories containing a scalar coupling with the Gauss-Bonnet (GB) curvature invariant $R_{\rm GB}^2$, we study the existence and linear stability of neutron star (NS) solutions on a static and spherically symmetric background.…

General Relativity and Quantum Cosmology · Physics 2022-09-08 Masato Minamitsuji , Shinji Tsujikawa

In this work we investigate neutron stars (NS) in $f(\mathcal{R,T})$ gravity for the case $R+2\lambda\mathcal{T}$, $\mathcal{R}$ is the Ricci scalar and $\mathcal{T}$ the trace of the energy-momentum tensor. The hydrostatic equilibrium…

High Energy Astrophysical Phenomena · Physics 2021-01-01 R. Lobato , O. Lourenço , P. H. R. S. Moraes , C. H. Lenzi , M. de Avellar , W. de Paula , M. Dutra , M. Malheiro

We study neutron star configurations in a teleparallel gravity model featuring a scalar field coupled to both matter and torsion. In the Einstein frame, the theory includes a derivative coupling between the scalar field and the torsion…

General Relativity and Quantum Cosmology · Physics 2026-03-25 Youcef Kehal , Khireddine Nouicer

In this work, we investigate the existence of neutron stars (NS) in the framework of $f$($\mathbb{T}$,$\mathcal{T}$) gravity, where $\mathbb{T}$ is the torsion tensor and $\mathcal{T}$ is the trace of the energy-momentum tensor. The…

High Energy Astrophysical Phenomena · Physics 2023-01-11 Clésio E. Mota , Luis C. N. Santos , Franciele M. da Silva , Cesar V. Flores , Iarley P. Lobo , Valdir B. Bezerra

We study static, spherically symmetric neutron stars in a class of scalar-tensor theories with non-canonical kinetic terms (K-essence) obeying all causality and hyperbolicity conditions. These models have non-trivial dynamics that lead to a…

General Relativity and Quantum Cosmology · Physics 2025-09-12 Mark P. Hertzberg , Oleksandr S. Stashko

The macroscopic properties of compact stars in modified gravity theories can be significantly different from the general relativistic (GR) predictions. Within the gravitational context of scalar-tensor theories, with a scalar field $\phi$…

General Relativity and Quantum Cosmology · Physics 2023-12-05 Juan M. Z. Pretel , Sergio E. Jorás , Ribamar R. R. Reis , Sergio B. Duarte , José D. V. Arbañil

We are investigating universal relations between different normalisations of the moment of inertia and the compactness of neutron stars in slow rotation approximation. We study the relations in particular class of massive scalar-sensor…

General Relativity and Quantum Cosmology · Physics 2019-03-27 Dimitar Popchev , Kalin V. Staykov , Daniela D. Doneva , Stoytcho S. Yazadjiev

We numerically construct compact stars in the scalar-tensor theory of gravity with non-minimal derivative coupling of a scalar field to the curvature and nonzero cosmological constant. There are two free parameters in this model of gravity:…

General Relativity and Quantum Cosmology · Physics 2025-04-08 P. E. Kashargin , A. A. Lebedev , S. V. Sushkov

In $f(R)$ gravity and Brans-Dicke theory with scalar potentials, we study the structure of neutron stars on a spherically symmetric and static background for two equations of state: SLy and FPS. In massless BD theory, the presence of a…

General Relativity and Quantum Cosmology · Physics 2019-10-04 Ryotaro Kase , Shinji Tsujikawa

Neutron star properties, such as its mass, radius, and moment of inertia, are calculated by solving the Tolman-Oppenheimer-Volkov (TOV) equations using the ring-diagram equation of state (EOS) obtained from realistic low-momentum NN…

Nuclear Theory · Physics 2009-12-31 Huan Dong , T. T. S. Kuo , R. Machleidt

We construct rapidly rotating neutron star models in scalar-tensor theories with a massive scalar field. The fact that the scalar field has nonzero mass leads to very interesting results since the allowed range of values of the coupling…

General Relativity and Quantum Cosmology · Physics 2016-11-15 Daniela D. Doneva , Stoytcho S. Yazadjiev

We study torsional oscillations of neutron stars in the scalar-tensor theory of gravity using the relativistic Cowling approximation. We compute unperturbed neutron star models adopting realistic equations of state for the neutron star's…

General Relativity and Quantum Cosmology · Physics 2014-12-24 Hector O. Silva , Hajime Sotani , Emanuele Berti , Michael Horbatsch

We present the field equations governing the equilibrium of rapidly rotating neutron stars in scalar-tensor theories of gravity, as well as representative numerical solutions. The conditions for the presence of a nontrivial scalar field and…

General Relativity and Quantum Cosmology · Physics 2014-02-25 Daniela D. Doneva , Stoytcho S. Yazadjiev , Nikolaos Stergioulas , Kostas D. Kokkotas

A novel equation of state with the surface tension induced by particles' interactions was generalized to describe the properties of the neutron stars (NSs). In this equation the interaction between particles occurs via the hard core…

High Energy Astrophysical Phenomena · Physics 2017-12-19 Violetta V. Sagun , Ilidio Lopes

Universal relations that are insensitive to the equation of state (EoS) are useful in reducing the parameter space when measuring global quantities of neutron stars (NSs). In this paper, we reveal a new universal relation that connects the…

High Energy Astrophysical Phenomena · Physics 2023-08-22 Yong Gao , Lijing Shao , Jan Steinhoff

The class of scalar-tensor theories with the scalar field coupling to the Gauss-Bonnet invariant has drawn great interest since solutions of spontaneous scalarization were found for black holes in these theories. We contribute to the…

General Relativity and Quantum Cosmology · Physics 2022-01-05 Rui Xu , Yong Gao , Lijing Shao

We study neutron stars in a varying speed of light (VSL) theory of gravity in which the local speed of light depends upon the value of a scalar field $\phi$. We find that the masses and radii of the stars are strongly dependent on the…

General Relativity and Quantum Cosmology · Physics 2009-11-10 A. W. Whinnett
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