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Related papers: Neutron Stars in Aether Scalar-Tensor Theory

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The realistic models of neutron stars are considered for simple $R+\alpha R^2$ gravity and equivalent Brance-Dicke theory with dilaton field in Einsein frame. For negative values of $\alpha$ we have no acceptable results from astrophysical…

General Relativity and Quantum Cosmology · Physics 2018-12-27 Artyom V. Astashenok , Alexey S. Baigashov , Sergey A. Lapin

We systematically study the observable properties of dark-matter admixed neutron stars, employing a realistic nuclear EOS in combination with self-interacting fermionic dark matter respecting constraints on the self-interaction cross…

Nuclear Theory · Physics 2024-10-23 Hong-Ming Liu , Jin-Biao Wei , Zeng-Hua Li , G. F. Burgio , H. C. Das , H. -J. Schulze

Unlike general relativity, the scalar gravitational waves can be excited due to the radial oscillations in scalar-tensor gravity. To examine the scalar gravitational waves in scalar-tensor gravity, we derive the evolution equations of the…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Hajime Sotani

We investigate the properties of neutron stars when a massive scalar field, which could comprise all dark matter, is non-minimally coupled to the Ricci scalar. This coupling generates additional contributions to the field's effective mass,…

General Relativity and Quantum Cosmology · Physics 2026-03-17 Suchana Adhikari , Teruaki Suyama

Neutron stars are regarded as natural laboratories for the study of dense strong interaction matter. The equation of state (EoS) of dense matter computed in flat spacetime is used to predict the structure of neutron stars by solving the…

General Relativity and Quantum Cosmology · Physics 2022-10-27 Jianing Li , Tao Guo , Jiaxing Zhao , Lianyi He

Neutron stars provide an ideal theoretical framework for exploring fundamental physics when nuclear matter surpasses densities encountered within atomic nuclei. Despite their paramount importance, uncertainties in the equation of state…

High Energy Astrophysical Phenomena · Physics 2025-01-31 Grigorios Papigkiotis , Georgios Vardakas , Aristidis Likas , Nikolaos Stergioulas

We obtain a mass function solving the Tolman-Oppenheimer-Volkoff (TOV) equation for isotropic and spherically symmetric system via homotopy perturbation method (HPM). Using the mass function we construct a stellar model which can be…

General Relativity and Quantum Cosmology · Physics 2019-11-04 Abdul Aziz , Saibal Ray , Farook Rahaman , B. K. Guha

This work concerns the loss of energy of a material system due to gravitational radiation in Einstein-aether theory-an alternative theory of gravity in which the metric couples to a dynamical, timelike, unit-norm vector field. Derived to…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Brendan Z. Foster

We present novel neutral and uncharged solutions that describe the cluster of Einstein in the teleparallel equivalent of general relativity (TEGR). To this end, we use a tetrad field with non-diagonal spherical symmetry which gives the…

General Relativity and Quantum Cosmology · Physics 2023-11-22 G. G. L. Nashed , Amare Abebe , Kazuharu Bamba

We analyze the observational and theoretical constraints on ``Einstein-aether theory", a generally covariant theory of gravity coupled to a dynamical, unit, timelike vector field that breaks local Lorentz symmetry. The results of a…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Brendan Z. Foster , Ted Jacobson

The early 21st century witnesses a dramatic rise in the study of thermal radiation of neutron stars. Modern space telescopes have provided a wealth of valuable information which, when properly interpreted, can elucidate the physics of…

Solar and Stellar Astrophysics · Physics 2016-01-06 A. Y. Potekhin

The Aether-Scalar-Tensor (AeST) theory is an extension of General Relativity (GR) which can support Modified Newtonian Dynamics (MOND) behaviour in its static weak-field limit, and cosmological evolution resembling $\Lambda$CDM. We consider…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-05 Amel Durakovic , Constantinos Skordis

The properties of neutron stars are investigated within the relativistic central variational method by using a realistic nucleon-nucleon ($NN$) interaction. The strong repulsion of realistic $NN$ interactions at short distances is treated…

Nuclear Theory · Physics 2017-03-08 Jinniu Hu , Hong Shen , Hiroshi Toki

We present here some recent results concerning scalar-tensor Dark Energy models. These models are very interesting in many respects: they allow for a consistent phantom phase, the growth of matter perturbations is modified. Using a…

Astrophysics · Physics 2016-11-15 R. Gannouji , D. Polarski , A. Ranquet , A. A. Starobinsky

We investigate the evolution of cosmological perturbations in models of dark energy described by a time-like unit normalized vector field specified by a general function $\mathcal{F}(\mathcal{K})$, so-called Generalized Einstein-Aether…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-04 Richard A. Battye , Francesco Pace , Damien Trinh

We calculate total masses and radii of neutron stars (NS) for pure neutron matter and nuclear matter in beta-equilibrium. We apply a relativistic nuclear matter equation of state (EOS) derived from Dirac-Brueckner-Hartree-Fock (DBHF)…

Nuclear Theory · Physics 2009-11-11 Plamen G. Krastev , Francesca Sammarruca

Scalar-tensor theories are the best motivated alternatives to general relativity and provide a mathematically consistent framework to test the various observable predictions. They can involve three functions of the scalar field: (i) a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Gilles Esposito-Farese

We derive the equation for pressure within a neutron star, taking into account a non-zero cosmological constant ($\Lambda$). We then examine the stability of the neutron star's equilibrium state in the presence of cosmological constant. Our…

General Relativity and Quantum Cosmology · Physics 2025-04-22 Naveen K. Singh , Gopal Kashyap

We provide a set of general tools to study the problem of stellar equilibrium in any gravitational theory in which spherically symmetric spacetimes satisfy master field equations taking the form of an equality between an identically…

General Relativity and Quantum Cosmology · Physics 2026-03-26 Julio Arrechea , Raúl Carballo-Rubio , Matt Visser

We consider a scalar-tensor theory of gravitation with the scalar source being the trace of the stress-energy tensor of the scalar field itself and matter. We obtain an example of a numerical solution of the cosmological equations which…

General Relativity and Quantum Cosmology · Physics 2016-10-05 I. G. Dudko , Yu. P. Vyblyi