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Related papers: Star equilibrium: from BNG to TOV

200 papers

We systematically examine the compactness of neutron stars as Tolman VII solutions in scalar-tensor theory of gravity. As a result, when the coupling constant is confined to values provided by astronomical observations we show that the…

General Relativity and Quantum Cosmology · Physics 2018-06-20 Hajime Sotani , Kostas D. Kokkotas

Along with compacting baryon (neutron) spacing, two very important factors come into play at once: the lack of self-stabilization within a compact neutron star (NS) associated with possible black hole (BH) horizon appearance and the phase…

High Energy Physics - Phenomenology · Physics 2009-06-11 Ilya I. Royzen

In this paper, we introduce a novel analytical solution to Tolman-Oppenheimer-Volkoff (TOV) equation, which is ultimately a hydrostatic equilibrium equation derived from the general relativity in the framework of relativistic isothermal…

General Relativity and Quantum Cosmology · Physics 2017-05-01 A. S. Saad , M. I. Nouh , A. A. Shaker , T. M. Kamel

Complete tensor-scalar and hydrodynamic equations are presented and integrated, for a self-gravitating perfect fluid. The initial conditions describe unstable-equilibrium neutron star configuration, with a polytropic equation of state. They…

General Relativity and Quantum Cosmology · Physics 2009-10-30 J. Novak

We present strong evidence that semiclassical gravity can give place to self-consistent ultracompact stars beyond the Buchdahl limit. We integrate the semiclassical equations of (spherically symmetric) stellar equilibrium for a…

General Relativity and Quantum Cosmology · Physics 2022-09-27 Julio Arrechea , Carlos Barceló , Raúl Carballo-Rubio , Luis J. Garay

Bekenstein's Tensor-Vector-Scalar (TeVeS) theory has had considerable success as a relativistic theory of Modified Newtonian Dynamics (MoND). However, recent work suggests that the dynamics of the theory are fundamentally flawed and…

High Energy Astrophysical Phenomena · Physics 2009-10-29 Paul D. Lasky

Inspired by the BTZ formalism, we discuss the Maxwell-$f(T)$ gravity in (2+1)-dimensions. The main task is to derive exact solutions for a special form of $f(T)=T+\epsilon T^2$, with $T$ being the torsion scalar of…

General Relativity and Quantum Cosmology · Physics 2018-05-23 G. G. L. Nashed , S. Capozziello

In this work, the interior spacetime of stars is built in a Lorentz symmetry breaking model called bumblebee gravity. Firstly, we calculated the modified Tolman-Oppenheimer-Volkoff equation in this context of modified gravity. Then we show…

General Relativity and Quantum Cosmology · Physics 2025-02-13 Juliano C. S. Neves , Fernando G. Gardim

Models of neutron stars (NSs) with hyperon cores are constructed with an effective chiral model in mean-field approximation. The hyperon couplings are fixed by reproducing their experimentally determined binding energies. The impact of…

Nuclear Theory · Physics 2019-01-31 Debashree Sen , Kinjal Banerjee , T. K. Jha

In this work, we investigate an anisotropic compact star's physical properties and stability in F(Q) gravity. The study focuses on the significance of F(Q) gravity on the structure and stability of compact star, considering non-perfect…

General Relativity and Quantum Cosmology · Physics 2024-09-26 Sat Paul , Jitendra Kumar , Sunil Kumar Maurya , Sourav Choudhary , Sweeti Kiroriwala

We consider boson stars and black holes in scalar electrodynamics with a V-shaped scalar potential. The boson stars come in two types, having either ball-like or shell-like charge density. We analyze the properties of these solutions and…

General Relativity and Quantum Cosmology · Physics 2010-11-22 Burkhard Kleihaus , Jutta Kunz , Claus Laemmerzahl , Meike List

We connect two formalisms that describe deformations away from general relativity, one valid in the strong-field regime of neutrons stars and another valid in the radiative regime of gravitational waves: the post-Tolman-Oppenheimer-Volkoff…

General Relativity and Quantum Cosmology · Physics 2019-11-11 Hector O. Silva , Nicolás Yunes

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

Since the derivation of a well-defined $D\to4$ limit for 4D Einstein-Gauss-Bonnet (4DEGB) gravity coupled to a scalar field, there has been considerable interest in testing it as an alternative to Einstein's general theory of relativity.…

General Relativity and Quantum Cosmology · Physics 2025-04-25 Alejandro Saavedra , Octavio Fierro , Michael Gammon , Robert B. Mann , Guillermo Rubilar

First, we construct the Taub-NUT/bolt solutions of $(2k+2)$-dimensinal Einstein-Maxwell gravity, when all the factor spaces of $2k$-dimensional base space $\mathcal{B}$ have positive curvature. These solutions depend on two extra…

High Energy Physics - Theory · Physics 2008-11-26 M. H. Dehghani , A. Khodam-Mohammadi

In the quest for describing massive neutron stars with radii compatible with recent expectations, we take a different approach in the present paper and, instead of tuning the equations of state, we use an appropriate parameterization of the…

Nuclear Theory · Physics 2019-02-27 Clésio E. Mota , Guilherme Grams , Débora P. Menezes

We construct new charged solutions of the Einstein-Maxwell field equations with cosmological constant. These solutions describe the nut-charged generalisation of the higher dimensional Reissner-Nordstr\"{o}m spacetimes. For a negative…

High Energy Physics - Theory · Physics 2007-05-23 Robert B. Mann , Cristian Stelea

Motivated by the entropy-functional formulation of emergent gravity, in which spacetime is endowed with a thermodynamic entropy that, upon extremization, yields the Einstein field equations, we reformulate the onset of a neutron star as a…

General Relativity and Quantum Cosmology · Physics 2026-03-10 Wen-Xiang Chen

Black holes are normally and naturally associated to the end-point of gravitational collapse. Yet, alternatives have been proposed and a particularly interesting one is that of gravitational condensate stars, or gravastars. We here revisit…

General Relativity and Quantum Cosmology · Physics 2024-02-20 Daniel Jampolski , Luciano Rezzolla

Scalar-Tensor-Vector Gravity (STVG), also referred as MOdified Gravity (MOG), is an alternative theory of the gravitational interaction. Its weak field approximation has been successfully used to described Solar System observations, galaxy…

General Relativity and Quantum Cosmology · Physics 2017-02-02 Federico G. Lopez Armengol , Gustavo E. Romero