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Related papers: Approximate Spacetime for Neutron Stars

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The problem of having an accurate description of the spacetime around neutron stars is of great astrophysical interest. For astrophysical applications, one needs to have a metric that captures all the properties of the spacetime around a…

General Relativity and Quantum Cosmology · Physics 2017-02-09 George Pappas

Approximate all-terrain spacetimes for astrophysical applications are presented. The metrics possess five relativistic multipole moments, namely mass, rotation, mass quadrupole, charge, and magnetic dipole moment. All these spacetimes…

General Relativity and Quantum Cosmology · Physics 2024-11-25 Francisco Frutos-Alfaro

A new Kerr-like metric with quadrupole moment is obtained by means of perturbing the Kerr spacetime. The form of this new metric is simple as the Kerr metric. By comparison with the exterior Hartle-Thorne metric, it is shown that it could…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-15 Francisco Frutos-Alfaro , Paulo Montero-Camacho , Miguel Araya-Arguedas , Javier Bonatti-Gonzalez

Using stellar structure calculations in the Hartle-Thorne approximation, we derive analytic expressions connecting the ellipticity of the stellar surface to the compactness, the spin angular momentum, and the quadrupole moment of the…

High Energy Astrophysical Phenomena · Physics 2015-06-16 Michi Baubock , Emanuele Berti , Dimitrios Psaltis , Feryal Ozel

A new Kerr-like metric with quadrupole moment is obtained by means of perturbing the Kerr spacetime. By comparison with the exterior Hartle-Thorne metric, it is showed that it could be matched to an interior solution. This metric may…

General Relativity and Quantum Cosmology · Physics 2014-01-09 Francisco Frutos-Alfaro

The Kerr metric is known to present issues when trying to find an interior solution. In this work we continue in our efforts to construct a more realistic exterior metric for astrophysical objects. A new approximate metric representing the…

General Relativity and Quantum Cosmology · Physics 2016-09-02 Francisco Frutos-Alfaro , Paulo Montero-Camacho

In this article we present some recent results on identifying correctly the relativistic multipole moments of numerically constructed spacetimes, and the consequences that this correction has on searching for appropriate analytic spacetimes…

General Relativity and Quantum Cosmology · Physics 2012-11-28 George Pappas , Theocharis A Apostolatos

A new approximate metric representing the spacetime of a rotating deformed body is obtained by perturbing the Kerr metric to include til the second order of the quadrupole moment. It has a simple form, because is Kerr-like. Its Taylor…

General Relativity and Quantum Cosmology · Physics 2018-11-30 Francisco Frutos-Alfaro

Measurement of at least three independent parameters, for example, mass, radius and spin frequency, of a neutron star is probably the only way to understand the nature of its supranuclear core matter. Such a measurement is extremely…

High Energy Astrophysical Phenomena · Physics 2015-05-14 Sudip Bhattacharyya

A moderately spinning neutron star acquires an oblate shape and a spacetime with a significant quadrupole moment. These two properties affect its apparent surface area for an observer at infinity, as well as the lightcurve arising from a…

High Energy Astrophysical Phenomena · Physics 2015-05-30 Michi Baubock , Dimitrios Psaltis , Feryal Ozel , Tim Johannsen

The exterior geometry of a neutron star can be approximated by relativistic multipole moments of a parametrized metric using Ernst potential formalism. This spacetime can be tested with electromagnetic wave observation of astrophysical…

General Relativity and Quantum Cosmology · Physics 2018-02-06 M. Ghasemi-Nodehi

We calculate the total mass, radius, moment of inertia and surface gravitational redshift for neutron stars using various equations of state. The latter are derived from recent meson-exchange potential models, employing both a relativistic…

Nuclear Theory · Physics 2009-10-22 Bao , Engvik , Hjorth-Jensen , Osnes , Oestgaard

We derive the empirical formulas for the neutron star mass and gravitational redshift as a function of the central density and specific combination of the nuclear saturation parameters, which are applicable to the stellar models constructed…

Nuclear Theory · Physics 2022-03-23 Hajime Sotani , Hajime Togashi

Neutron stars are compact and dense celestial objects that offer the unique opportunity to explore matter and its interactions under conditions that cannot be reproduced elsewhere in the Universe. Their extreme gravitational, rotational and…

High Energy Astrophysical Phenomena · Physics 2024-01-29 Stefano Ascenzi , Vanessa Graber , Nanda Rea

The 4-parameter exact solution presumably describing the exterior gravitational field of a generic neutron star is presented in a concise explicit form defined by only three potentials. In the equatorial plane, the metric functions of the…

General Relativity and Quantum Cosmology · Physics 2016-06-01 V. S. Manko , E. Ruiz

We propose to determine the mass and the radius of a neutron star (NS) using three measurable mass-radius relationships, namely the ``apparent'' radius inferred from neutron star thermal emission, the gravitational redshift inferred from…

Astrophysics · Physics 2008-11-26 C. M. Zhang , H. X. Yin , Y. Kojima , H. K. Chang , R. X. Xu , X. D. Li , B. Zhang , B. Kiziltan

We consider a universal relation between moment of inertia and quadrupole moment of arbitrarily fast rotating neutron stars. Recent studies suggest that this relation breaks down for fast rotation. We find that it is still universal among…

General Relativity and Quantum Cosmology · Physics 2014-06-30 Sayan Chakrabarti , Térence Delsate , Norman Gürlebeck , Jan Steinhoff

Different forms of the metric for the Kerr-NUT-(anti-)de Sitter space-time are being widely used in its extension to higher dimensions. The purpose of this note is to relate the parameters that are being used to the physical parameters…

General Relativity and Quantum Cosmology · Physics 2008-11-26 J. B. Griffiths , J. Podolsky

We compare three different models of rotating neutron star spacetimes: the Hartle-Thorne (HT) slow-rotation approximation at second order in rotation, the exact analytic vacuum solution of Manko et al. and a numerical solution of the full…

General Relativity and Quantum Cosmology · Physics 2011-05-23 Emanuele Berti , Frances White , Asimina Maniopoulou , Marco Bruni

We present results for models of neutron stars and strange stars constructed using the Hartle-Thorne slow-rotation method with a wide range of equations of state, focusing on the values obtained for the angular momentum $J$ and the…

Solar and Stellar Astrophysics · Physics 2015-06-12 Martin Urbanec , John C. Miller , Zdenek Stuchlik
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