English
Related papers

Related papers: Neutron Stars in Rastall Gravity

200 papers

Quartic gravity theory is considered with the Einstein-Hilbert Lagrangean $R+aR^{2}+bR_{\mu \nu}R^{\mu \nu},$ $R_{\mu \nu}$ being Ricci\'s tensor and R the curvature scalar. The parameters $a$ and $b$ are taken of order 1 km$^{2}.$…

General Relativity and Quantum Cosmology · Physics 2021-06-16 Emilio Santos

We study oscillations and instabilities of relativistic stars using perturbation theory in general relativity and take into account the contribution of a dynamic spacetime. We present the oscillation spectrum as well as the critical values…

General Relativity and Quantum Cosmology · Physics 2020-09-16 C. J. Krüger , K. D. Kokkotas

In the present paper we investigate non-perturbatively and self-consistently the structure of neutron stars in $R$-squared gravity by simultaneously solving the interior and exterior problem. The mass-radius relations are obtained for…

General Relativity and Quantum Cosmology · Physics 2015-06-18 Stoytcho S. Yazadjiev , Daniela D. Doneva , Kostas D. Kokkotas , Kalin V. Staykov

A promising theory in modifying general relativity by violating the ordinary energy-momentum conservation law in curved spacetime is the Rastall theory of gravity. In this theory, geometry and matter fields are coupled to each other in a…

General Relativity and Quantum Cosmology · Physics 2018-03-12 Iarley P. Lobo , H. Moradpour , J. P. Morais Graça , I. G. Salako

In this paper we investigate the gravitational vacuum stars which called gravastars in the non-minimally coupled models with electromagnetic and gravitational fields. We consider two non-minimal models and find the corresponding spherically…

General Relativity and Quantum Cosmology · Physics 2021-11-18 Özcan Sert , Muzaffer Adak

Motivated by the recent interests in spin$-2$ massive gravitons, we study the structure of neutron star in the context of massive gravity. The modifications of TOV equation in the presence of massive gravity are explored in $4$ and higher…

General Relativity and Quantum Cosmology · Physics 2017-07-25 S. H. Hendi , G. H. Bordbar , B. Eslam Panah , S. Panahiyan

Neutron stars are highly compact astrophysical objects and therefore of utmost relevance to learn about theories of gravity. Whereas the proper equation of state of the nuclear matter inside neutron stars is not yet known, and a wide range…

General Relativity and Quantum Cosmology · Physics 2022-04-28 Jutta Kunz

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

The understanding of stellar structure represents the crossroads of our theories of the nuclear force and the gravitational interaction under the most extreme conditions observably accessible. It provides a powerful probe of the strong…

General Relativity and Quantum Cosmology · Physics 2020-09-15 Gonzalo J. Olmo , Diego Rubiera-Garcia , Aneta Wojnar

The Nordstr\"om-Vlasov system is a relativistic Lorentz invariant generalization of the Vlasov-Poisson system in the gravitational case. The asymptotic behavior of solutions and the non-linear stability of steady states are investigated. It…

Mathematical Physics · Physics 2009-11-13 Simone Calogero , Oscar Sanchez , Juan Soler

We calculate crustal properties of neutron stars, namely, mass ($M_{\rm crust}$), radius ($R_{\rm crust}$) and fraction of moment of inertia ($\Delta I/I$) from parametrizations of hadronic relativistic mean-field (RMF) model consistent…

Nuclear Theory · Physics 2021-10-05 M. Dutra , C. H. Lenzi , W. de Paula , O. Lourenço

We discuss the stability and construct dynamical configurations describing the gravitational collapse of unstable neutron stars with realistic equations of state compatible with the recent LIGO-Virgo constraints. Unlike other works that…

General Relativity and Quantum Cosmology · Physics 2020-06-17 J. M. Z. Pretel , M. F. A. da Silva

Gravastars have been considered as a feasible alternative to black holes in the past couple of decades. Stable models of gravastar have been studied in many of the alternative gravity theories besides standard General Relativity (GR). The…

General Relativity and Quantum Cosmology · Physics 2021-07-14 Shounak Ghosh , Sagar Dey , Amit Das , Anirban Chanda , B C Paul

Gravastars are considered as one of the prime exotic type compact objects which may be found at the end state of gravitational collapse of massive stars with a view to resolve the complexities that are pertinent in case of a black hole…

General Relativity and Quantum Cosmology · Physics 2024-08-22 Debadri Bhattacharjee , Pradip Kumar Chattopadhyay

We develop the general theory of stars in Saa's model of gravity with propagating torsion and study the basic stationary state of neutron star. Our numerical results show that the torsion force decreases the role of the gravity in the star…

General Relativity and Quantum Cosmology · Physics 2010-11-19 T. Boyadjiev , P. Fiziev , S. Yazadjiev

Rastall gravity is a generalization of the Einstein gravity in which the matter is not conserved in the presence of a non-constant spacetime curvature. In this report, we analyze Rastall gravity using the linearized formalism. The…

General Relativity and Quantum Cosmology · Physics 2025-05-12 Yuwadee Tongkong

In this work, we generalized the Kerr-Newman-NUT black hole solution in Rastall gravity from Ref. 1. Here we are more focused on the black hole dynamics such as the event horizons, ergosurface, ZAMO, thermodynamic properties, and the…

General Relativity and Quantum Cosmology · Physics 2020-02-27 Hadyan L. Prihadi , Muhammad F. A. R. Sakti , Getbogi Hikmawan , Freddy P. Zen

Millisecond pulsars are perfect laboratories to test possible matter-geometry coupling and its physical implications in light of recent Neutron Star Interior Composition Explorer (NICER) observations. We apply Rastall field equations of…

High Energy Astrophysical Phenomena · Physics 2022-11-22 Waleed El Hanafy

The effects implied for the structure of compact objects by the modification of General Relativity produced by the generalization of the Lagrangian density to the form f(R)=R+\alpha R^2, where R is the Ricci curvature scalar, have been…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-24 Mariana Orellana , Federico García , Florencia Anabella Teppa Pannia , Gustavo Esteban Romero

In this paper, we study the slowly rotating neutron stars in $f(R, T)$ gravity based on Hartle-Thorne formalism. We first consider the simplest matter-geometry coupled modified gravity, namely $f(R, T)=R+2\chi T$. We compute the mass,…

General Relativity and Quantum Cosmology · Physics 2024-09-16 Masum Murshid , Mehedi Kalam