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Related papers: Conformal coordinates of a constant density star

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We present an algorithm for the construction of conformal coordinates in the interior of a spherically symmetric, collapsing matter cloud in general relativity. This algorithm is based on the numerical integration of the radial null…

General Relativity and Quantum Cosmology · Physics 2014-06-17 Néstor Ortiz , Olivier Sarbach

We consider a spherically symmetric stellar model in general relativity whose interior consists of a pressureless fluid undergoing microscopic velocity diffusion in a cosmological scalar field. We show that the diffusion dynamics compel the…

General Relativity and Quantum Cosmology · Physics 2017-08-23 Artur Alho , Simone Calogero

An identity of conformal-projective curvature tensor of a statistical manifold is studied in this paper. The relation between the constancy of curvature and conformal-projective flatness of statistical manifolds is also discussed.

Differential Geometry · Mathematics 2016-08-04 Min Cholrim , Ri Wonhak , Kwak Kumhyok

We present a spherically symmetric solution of the general relativistic field equations in isotropic coordinates for charged fluid with pressure anisotropy, compatible with a super dense star modeling. Further, we have constructed an…

General Physics · Physics 2015-02-12 Ksh. Newton Singh , Narendra Pradhan , Manuel Malaver

In this manuscript, we study the nearly flat approximation of a conformally invariant gravitational theory in metric measure space (MMS). In addition, we investigate the transformation of the energy-momentum tensor in this context and…

General Relativity and Quantum Cosmology · Physics 2023-02-28 Samaneh Oghbaiee , Nafiseh Rahmanpour , Hossein Shojaie

Cone spherical metrics are conformal metrics with constant curvature one and finitely many conical singularities on compact Riemann surfaces. A cone spherical metric is called irreducible if each developing map of the metric does not have…

Algebraic Geometry · Mathematics 2022-10-11 Lingguang Li , Jijian Song , Bin Xu

We investigate the geodesic structure of realistic static and spherically symmetric spacetimes embedding neutron stars in metric $f(R)$ gravity, focusing on the quadratic Starobinsky model $f(R)=aR^2$ with $a<0$. Neutron-star solutions are…

General Relativity and Quantum Cosmology · Physics 2026-03-10 Néstor Rivero González , Álvaro de la Cruz Dombriz , Gonzalo J. Olmo

We demonstrate that there is an inherent symmetry in the way high-overtone stellar pulsations sample the core and the envelope, which can potentially lead to an ambiguity in the asteroseismologically derived locations of internal…

Astrophysics · Physics 2009-11-07 M. H. Montgomery , T. S. Metcalfe , D. E. Winget

We consider static spherically symmetric self-gravitating configurations of the perfect fluid within the framework of the torsion-based extended theory of gravity. In particular, we use the covariant formulation of $f(T)$ gravity with $f(T)…

General Relativity and Quantum Cosmology · Physics 2018-10-03 Sasa Ilijic , Marko Sossich

A class of general relativistic solutions in isotropic spherical polar coordinates are discussed which describe compact stars in hydrostatic equilibrium. The stellar models obtained here are characterized by four parameters, namely,…

Solar and Stellar Astrophysics · Physics 2015-06-17 Rumi Deb , Bikash Chandra Paul , Ramesh Tikekar

Let $S$ be the 2-sphere and $V \subset S$ be a finite set of at least three points. We show that for each function $\kappa: V \rightarrow (0, 2\pi)$ satisfying elementary necessary conditions, in each discrete conformal class of spherical…

Metric Geometry · Mathematics 2023-11-30 Ivan Izmestiev , Roman Prosanov , Tianqi Wu

We derive the form of the metric for static, nonsingular black holes with a de Sitter core, representing a deformation of the Schwarzschild solution, by assuming that the gravitational sources describe a flow between two conformal points,…

General Relativity and Quantum Cosmology · Physics 2023-06-30 Mariano Cadoni , Andrea Pierfrancesco Sanna

In this article, an exact solution of Einstein's field equations for spherically symmetric anisotropic matter distributions in isotropic coordinates is obtained. For this, the solution has been obtained by using a generalized physically…

General Relativity and Quantum Cosmology · Physics 2025-08-25 B S Ratanpal , Bhavesh Suthar

Compact objects, like neutron stars and white dwarfs, may accrete dark matter, and then be sensitive probes of its presence. These compact stars with a dark matter component can be modeled by a perfect fluid minimally coupled to a complex…

General Relativity and Quantum Cosmology · Physics 2015-11-03 Susana Valdez-Alvarado , Carlos Palenzuela , Daniela Alic , L. Arturo Ureña-López

All possible transformations from the Robertson-Walker metric to those conformal to the Lorentz-Minkowski form are derived. It is demonstrated that the commonly known family of transformations and associated conformal factors are not…

General Relativity and Quantum Cosmology · Physics 2008-11-26 M. Ibison

A model approach to the description of static stars filled with a charged Pascal perfect fluid within the framework of general relativity is investigated. The metric is written in Bondi's radiation coordinates. The gravitational equations…

General Relativity and Quantum Cosmology · Physics 2012-01-24 A. M. Baranov

Spherically symmetric solutions in F(R) theories in astronomical systems with rising energy density are studied. The range of parameters is established for which the flat space-time approximation for the background metric is valid. For the…

General Relativity and Quantum Cosmology · Physics 2015-06-16 E. V. Arbuzova , A. D. Dolgov , L. Reverberi

Here we study some general properties of spherical shear-free collapse. Its general solution when imposing conformal flatness is reobtained [1,2] and matched to the outgoing Vaidya spacetime. We propose a simple model satisfying these…

General Relativity and Quantum Cosmology · Physics 2008-11-26 L. Herrera , G. Le Denmat , N. O. Santos , A. Wang

A highly accurate, multi-domain spectral code is used in order to construct sequences of general relativistic, differentially rotating neutron stars in axisymmetry and stationarity. For bodies with a spheroidal topology and a homogeneous or…

General Relativity and Quantum Cosmology · Physics 2016-06-01 Marcus Ansorg , Dorota Gondek-Rosińska , Loïc Villain

We study in spherical symmetry the conformal compactification for hyperboloidal foliations with nonvanishing constant mean curvature. The conformal factor and the coordinates are chosen such that null infinity is at a fixed radial…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Anil Zenginoglu , Sascha Husa