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Related papers: Truncated post-Newtonian neutron star model

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We consider the classic problem of a compact fluid source that behaves non-relativistically and that radiates gravitational waves. The problem consists of determining the metric close to the source as well as far away from it. The…

General Relativity and Quantum Cosmology · Physics 2024-02-05 Jelle Hartong , Jørgen Musaeus

The dynamics, time evolution of the mass distribution, and gravitational wave signature of coalescing neutron stars described by polytropes are compared with three simulations published previously: (a) ``Run 2'' of Zhuge et al. (1994), (b)…

Astrophysics · Physics 2007-05-23 M. Ruffert , M. Rampp , H. -Th. Janka

In this article we analyze the post-Newtonian approximation of a generalization of the symmetric teleparallel gravity with the help of the parameterized post-Newtonian (PPN) formalism. This class of theories is based on a free function of…

General Relativity and Quantum Cosmology · Physics 2021-02-24 Kai Flathmann , Manuel Hohmann

We present numerical relativity simulations of nine-orbit equal-mass binary neutron star covering the quasicircular late inspiral and merger. The extracted gravitational waveforms are analyzed for convergence and accuracy. Second order…

General Relativity and Quantum Cosmology · Physics 2012-05-23 Sebastiano Bernuzzi , Marcus Thierfelder , Bernd Bruegmann

We develop a new approach to building cosmological models, in which small pieces of perturbed Minkowski space are joined together at reflection-symmetric boundaries in order to form a global, dynamical space-time. Each piece of this…

General Relativity and Quantum Cosmology · Physics 2016-04-12 Viraj A. A. Sanghai , Timothy Clifton

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 present work, we suggest studying neutron star with a conformal coupling by using the analytical expressions of realistic equations of state. The equations of perturbed and nonperturbed metrics, scalar field and the pressure of the…

General Relativity and Quantum Cosmology · Physics 2021-10-28 Hamza Boumaza

We study the role of the equilibrium equation in bootstrapped Newtonian gravity (BNG) by including terms inspired by the post-Newtonian expansion of the Tolman-Oppenheimer-Volkov (TOV) equation. We then compare (approximate) BNG solutions…

General Relativity and Quantum Cosmology · Physics 2025-04-29 Roberto Casadio , Octavian Micu

We consider the final evolutionary stages of a neutron star-black hole pair. According to the current paradigm, such systems eventually coalesce, which in some cases is accompanied by neutron-star tidal disruption. Using analytical methods,…

High Energy Astrophysical Phenomena · Physics 2024-10-17 Nikita Kramarev , Alexander Kuranov , Andrey Yudin , Konstantin Postnov

We study the importance of hydrodynamic effects on the evolution of coalescing binary neutron stars. Using an approximate energy functional constructed from equilibrium solutions for polytropic binary configurations, we incorporate…

Astrophysics · Physics 2009-10-22 D. Lai , F. A. Rasio , S. L. Shapiro

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

Determining the equation of state of matter at nuclear density and hence the structure of neutron stars has been a riddle for decades. We show how the imminent detection of gravitational waves from merging neutron star binaries can be used…

General Relativity and Quantum Cosmology · Physics 2014-09-05 Kentaro Takami , Luciano Rezzolla , Luca Baiotti

We study the Starobinsky or $R^2$ model of $f(R)=R+\alpha R^2$ for neutron stars with the structure equations represented by the coupled differential equations and the \emph{polytropic} type of the matter equation of state. The junction…

General Relativity and Quantum Cosmology · Physics 2017-10-11 Wei-Xiang Feng , Chao-Qiang Geng , W. F. Kao , Ling-Wei Luo

The modern nucleon-nucleon interaction of Myers and Swiatecki, adjusted to the properties of finite nuclei, the parameters of the mass formula, and the behavior of the optical potential is used to calculate the properties of…

Nuclear Theory · Physics 2009-10-30 Klaus Strobel , Fridolin Weber , Manfred K. Weigel , Christoph Schaab

The postcollapse structure of objects which form by gravitational condensation out of the expanding cosmological background universe is a key element in the theory of galaxy formation. Towards this end, we have reconsidered the outcome of…

Astrophysics · Physics 2007-05-23 Paul R. Shapiro , Ilian T. Iliev , Alejandro C. Raga

This paper addresses the evolution of an axially symmetric magnetic field in the core of a neutron star. The matter in the core is modeled as a system of two fluids, namely neutrons and charged particles, with slightly different velocity…

High Energy Astrophysical Phenomena · Physics 2025-09-10 F. Castillo , N. A. Moraga , M. E. Gusakov , J. A. Valdivia , A. Reisenegger

We construct quasiequilibrium sequences of black hole-neutron star binaries for arbitrary mass ratios by solving the constraint equations of general relativity in the conformal thin-sandwich decomposition. We model the neutron star as a…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Keisuke Taniguchi , Thomas W. Baumgarte , Joshua A. Faber , Stuart L. Shapiro

In this paper we explore how far the post-Newtonian theory goes in overcoming the difficulties associated with anisotropic homogeneous cosmologies in the Newtonian approximation. It will be shown that, unlike in the Newtonian case, the…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Tamath Rainsford

We study relativistic stars in the simplest model of the de Rham-Gabadadze-Tolley massive gravity which describes the massive graviton without ghost propagating mode. We consider the hydrostatic equilibrium, and obtain the modified…

General Relativity and Quantum Cosmology · Physics 2016-06-15 Taishi Katsuragawa , Shin'ichi Nojiri , Sergei D. Odintsov , Masashi Yamazaki

Within the framework of the scalar-tensor theory (STT), its second post-Newtonian (2PN) approximation is obtained with Chandrasekhar's approach. By focusing on an $N$-point-masses system as the first step, we reduce the metric to its 2PN…

General Relativity and Quantum Cosmology · Physics 2013-07-05 Xue-Mei Deng , Yi Xie