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Related papers: Truncated post-Newtonian neutron star model

200 papers

We describe two fitting schemes that aim to represent the high-density part of realistic equations of state for numerical simulations such as neutron star oscillations. The low-density part of the equation of state is represented by an…

High Energy Astrophysical Phenomena · Physics 2024-05-20 Gaël Servignat , Philip J. Davis , Jérôme Novak , Micaela Oertel , José A. Pons

Many of the currently available equations of state for core-collapse supernova simulations give large neutron star radii and do not provide large enough neutron star masses, both of which are inconsistent with some recent neutron star…

Solar and Stellar Astrophysics · Physics 2015-06-05 Andrew W. Steiner , Matthias Hempel , Tobias Fischer

In the present work, we obtain the hydrostatic equilibrium configurations of neutron stars in the recently proposed $f(R,\mathcal{L},T)$ theory of gravity, for which $R$ is the Ricci scalar, $\mathcal{L}$ is the matter lagrangian density,…

General Relativity and Quantum Cosmology · Physics 2024-02-26 J. A. S. Fortunato , P. H. R. S. Moraes , E. Brito , J. G. de Lima Júnior , T. S. Guerini

We present a numerical method to compute quasiequilibrium configurations of close binary neutron stars in the pre-coalescing stage. A hydrodynamical treatment is performed under the assumption that the flow is either rigidly rotating or…

General Relativity and Quantum Cosmology · Physics 2009-10-31 E. Gourgoulhon , P. Grandclement , K. Taniguchi , J. -A. Marck , S. Bonazzola

Out-of-equilibrium reactions between different particle species are the main processes contributing to bulk viscosity in neutron stars. In this work, we numerically compare three different approaches to the modeling of bulk viscosity: the…

General Relativity and Quantum Cosmology · Physics 2023-05-23 Giovanni Camelio , Lorenzo Gavassino , Marco Antonelli , Sebastiano Bernuzzi , Brynmor Haskell

A detailed account is given on approximation schemes to the Einstein theory of general relativity where the iteration starts from the Newton theory of gravity. Two different coordinate conditions are used to represent the Einstein field…

General Relativity and Quantum Cosmology · Physics 2024-05-19 Gerhard Schäfer

Pad\'e approximants to truncated post-Newtonian neutron star models are constructed. The Pad\'e models converge faster to the general relativistic (GR) solution than the truncated post-Newtonian ones. The evolution of initial data using the…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Anshu Gupta , A. Gopakumar , Bala R. Iyer , Sai Iyer

We analyze several aspects of the recently noted neutron star collapse instability in close binary systems. We utilize (3+1) dimensional and spherical numerical general relativistic hydrodynamics to study the origin, evolution, and…

Astrophysics · Physics 2009-10-30 G. J. Mathews , J. R. Wilson

The equation of state inside very compact objects like neutron stars is still largely unkown. Even though a lot progress has been made in recent years to develop the so-called realistic equations of state, a lot of insight can be gained by…

General Relativity and Quantum Cosmology · Physics 2011-06-10 F. M. Araujo , C. B. M. H. Chirenti

The early post-merger phase of a binary neutron-star coalescence is shaped by characteristic rotational velocities as well as violent density oscillations and offers the possibility to constrain the properties of neutron star matter by…

General Relativity and Quantum Cosmology · Physics 2025-03-10 Michail Chabanov , Luciano Rezzolla

We consider both mode calculations and time evolutions of axial r-modes for relativistic uniformly rotating non-barotropic neutron stars, using the slow-rotation formalism, in which rotational corrections are considered up to linear order…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Johannes Ruoff , Kostas D. Kokkotas

We develop a semi-analytical approach, based on the post-Newtonian expansion and on the affine approximation, to model the tidal deformation of neutron stars in the coalescence of black hole-neutron star or neutron star-neutron star…

General Relativity and Quantum Cosmology · Physics 2015-06-03 V. Ferrari , L. Gualtieri , A. Maselli

In this paper, a modified version of the hydrostatic equilibrium equation based on the mimetic gravity in the presence of perfect fluid is revisited. By using the different known equation of states, the structural properties of neutron…

General Relativity and Quantum Cosmology · Physics 2022-05-10 Hajar Noshad , Seyed Hossein Hendi , Behzad Eslam Panah

We present the results from new relativistic hydrodynamic simulations of binary neutron star mergers using realistic non-zero temperature equations of state. We vary several unknown parameters in the system such as the neutron star (NS)…

Astrophysics · Physics 2009-11-11 Roland Oechslin , Thomas Janka

Models of neutron stars are considered in the case of a uniform density distribution. An algebraic equation, valid for any equation of state, is obtained. This equation allows one to find the approximate mass of a star of a given density…

High Energy Astrophysical Phenomena · Physics 2023-11-14 G. S. Bisnovatyi-Kogan , E. A. Patraman

We investigate the dynamics and evolution of coalescing neutron stars. The three-dimensional Newtonian equations of hydrodynamics are integrated by the `Piecewise Parabolic Method' However, we do include the effects of the emission of…

Astrophysics · Physics 2016-08-30 M. Ruffert , H. -Th. Janka , W. Keil , G. Schaefer

The bulk properties of spherically symmetric stars in general relativity can be obtained by integrating the Tolman-Oppenheimer-Volkoff (TOV) equations. In previous work we developed a "post-TOV" formalism - inspired by parametrized…

General Relativity and Quantum Cosmology · Physics 2016-08-17 Kostas Glampedakis , George Pappas , Hector O. Silva , Emanuele Berti

The observable macroscopic properties of relativistic stars (whose equations of state are known) can be predicted by solving the stellar structure equations that follow from Einstein's equation. For neutron stars, however, our knowledge of…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Lee Lindblom

We discuss slowly-rotating, general relativistic, superfluid neutron stars in the Hartle-Thorne formulation. The composition of the stars is described by a simple two-fluid model which accounts for superfluid neutrons and all other…

General Relativity and Quantum Cosmology · Physics 2023-03-21 Eneko Aranguren , José A. Font , Nicolas Sanchis-Gual , Raül Vera

We utilise the phenomenologically parameterized piecewise polytropic equations of state to study various neutron star properties. We investigate the compliance of these equations of state with several astronomical observations. We also…

Nuclear Theory · Physics 2022-05-04 Jaikhomba Singha , S. Mullai Vaneshwar , Ankit Kumar