The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Matt Visser - One of the best experts on this subject based on the ideXlab platform.
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Solution generating theorems for Perfect Fluid spheres
arXiv: General Relativity and Quantum Cosmology, 2007Co-Authors: Petarpa Boonserm, Matt Visser, Silke WeinfurtnerAbstract:The first static spherically symmetric Perfect Fluid solution with constant density was found by Schwarzschild in 1918. Generically, Perfect Fluid spheres are interesting because they are first approximations to any attempt at building a realistic model for a general relativistic star. Over the past 90 years a confusing tangle of specific Perfect Fluid spheres has been discovered, with most of these examples seemingly independent from each other. To bring some order to this collection, we develop several new transformation theorems that map Perfect Fluid spheres into Perfect Fluid spheres. These transformation theorems sometimes lead to unexpected connections between previously known Perfect Fluid spheres, sometimes lead to new previously unknown Perfect Fluid spheres, and in general can be used to develop a systematic way of classifying the set of all Perfect Fluid spheres. In addition, we develop new ''solution generating'' theorems for the TOV, whereby any given solution can be ''deformed'' to a new solution. Because these TOV-based theorems work directly in terms of the pressure profile and density profile it is relatively easy to impose regularity conditions at the centre of the Fluid sphere.
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Solution generating theorems: Perfect Fluid spheres and the TOV equation
arXiv: General Relativity and Quantum Cosmology, 2006Co-Authors: Petarpa Boonserm, Matt Visser, Silke WeinfurtnerAbstract:We report several new transformation theorems that map Perfect Fluid spheres into Perfect Fluid spheres. In addition, we report new ``solution generating'' theorems for the TOV, whereby any given solution can be ``deformed'' to a new solution.
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generating Perfect Fluid spheres in general relativity
Physical Review D, 2005Co-Authors: Petarpa Boonserm, Matt Visser, Silke WeinfurtnerAbstract:Ever since Karl Schwarzschild's 1916 discovery of the spacetime geometry describing the interior of a particular idealized general relativistic star--a static spherically symmetric blob of Fluid with position-independent density--the general relativity community has continued to devote considerable time and energy to understanding the general-relativistic static Perfect Fluid sphere. Over the last 90 years a tangle of specific Perfect Fluid spheres has been discovered, with most of these specific examples seemingly independent from each other. To bring some order to this collection, in this article we develop several new transformation theorems that map Perfect Fluid spheres into Perfect Fluid spheres. These transformation theorems sometimes lead to unexpected connections between previously known Perfect Fluid spheres, sometimes lead to new previously unknown Perfect Fluid spheres, and in general can be used to develop a systematic way of classifying the set of all Perfect Fluid spheres.
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algorithmic construction of static Perfect Fluid spheres
Physical Review D, 2004Co-Authors: Damien Martin, Matt VisserAbstract:Perfect Fluid spheres, both Newtonian and relativistic, have attracted considerable attention as the first step in developing realistic stellar models (or models for Fluid planets). Whereas there have been some early hints on how one might find general solutions to the Perfect Fluid constraint in the absence of a specific equation of state, explicit and fully general solutions of the Perfect Fluid constraint have only very recently been developed. In this article we present a version of Lake's algorithm [Phys. Rev. D 67 (2003) 104015; gr-qc/0209104] wherein: (1) we re-cast the algorithm in terms of variables with a clear physical meaning -- the average density and the locally measured acceleration due to gravity, (2) we present explicit and fully general formulae for the mass profile and pressure profile, and (3) we present an explicit closed-form expression for the central pressure. Furthermore we can then use the formalism to easily understand the pattern of inter-relationships among many of the previously known exact solutions, and generate several new exact solutions.
Silke Weinfurtner - One of the best experts on this subject based on the ideXlab platform.
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Solution generating theorems for Perfect Fluid spheres
arXiv: General Relativity and Quantum Cosmology, 2007Co-Authors: Petarpa Boonserm, Matt Visser, Silke WeinfurtnerAbstract:The first static spherically symmetric Perfect Fluid solution with constant density was found by Schwarzschild in 1918. Generically, Perfect Fluid spheres are interesting because they are first approximations to any attempt at building a realistic model for a general relativistic star. Over the past 90 years a confusing tangle of specific Perfect Fluid spheres has been discovered, with most of these examples seemingly independent from each other. To bring some order to this collection, we develop several new transformation theorems that map Perfect Fluid spheres into Perfect Fluid spheres. These transformation theorems sometimes lead to unexpected connections between previously known Perfect Fluid spheres, sometimes lead to new previously unknown Perfect Fluid spheres, and in general can be used to develop a systematic way of classifying the set of all Perfect Fluid spheres. In addition, we develop new ''solution generating'' theorems for the TOV, whereby any given solution can be ''deformed'' to a new solution. Because these TOV-based theorems work directly in terms of the pressure profile and density profile it is relatively easy to impose regularity conditions at the centre of the Fluid sphere.
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Solution generating theorems: Perfect Fluid spheres and the TOV equation
arXiv: General Relativity and Quantum Cosmology, 2006Co-Authors: Petarpa Boonserm, Matt Visser, Silke WeinfurtnerAbstract:We report several new transformation theorems that map Perfect Fluid spheres into Perfect Fluid spheres. In addition, we report new ``solution generating'' theorems for the TOV, whereby any given solution can be ``deformed'' to a new solution.
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generating Perfect Fluid spheres in general relativity
Physical Review D, 2005Co-Authors: Petarpa Boonserm, Matt Visser, Silke WeinfurtnerAbstract:Ever since Karl Schwarzschild's 1916 discovery of the spacetime geometry describing the interior of a particular idealized general relativistic star--a static spherically symmetric blob of Fluid with position-independent density--the general relativity community has continued to devote considerable time and energy to understanding the general-relativistic static Perfect Fluid sphere. Over the last 90 years a tangle of specific Perfect Fluid spheres has been discovered, with most of these specific examples seemingly independent from each other. To bring some order to this collection, in this article we develop several new transformation theorems that map Perfect Fluid spheres into Perfect Fluid spheres. These transformation theorems sometimes lead to unexpected connections between previously known Perfect Fluid spheres, sometimes lead to new previously unknown Perfect Fluid spheres, and in general can be used to develop a systematic way of classifying the set of all Perfect Fluid spheres.
F J Chinea - One of the best experts on this subject based on the ideXlab platform.
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A differentially rotating Perfect Fluid
Classical and Quantum Gravity, 1993Co-Authors: F J ChineaAbstract:The interior gravitational field of a particular stationary, axially symmetric, rotating Perfect Fluid with nonvanishing vorticity and shear is given in closed form. The field is nonstatic, and possesses no further isometries.
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interior gravitational field of a stationary axially symmetric Perfect Fluid in irrotational motion
Classical and Quantum Gravity, 1990Co-Authors: F J Chinea, L M GonzalezromeroAbstract:The interior metric for a steadily rotating, axially symmetric Perfect Fluid in irrotational motion is given, up to the remaining integration of a single first-order ordinary differential equation of the Abel type.
Gyula Fodor - One of the best experts on this subject based on the ideXlab platform.
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Perfect Fluid spheres with cosmological constant
Physical Review D, 2008Co-Authors: Christian G Bohmer, Gyula FodorAbstract:We examine static Perfect Fluid spheres in the presence of a cosmological constant. Because of the cosmological constant, new classes of exact matter solutions are found. One class of solutions requires the Nariai metric in the vacuum region. Another class generalizes the Einstein static universe such that neither its energy density nor its pressure is constant throughout the spacetime. Using analytical techniques we derive conditions depending on the equation of state to locate the vanishing pressure surface. This surface can, in general, be located in regions where, going outwards, the area of the spheres associated with the group of spherical symmetry is decreasing. We use numerical methods to integrate the field equations for realistic equations of state and find consistent results.
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Rotating Perfect Fluid sources of the NUT metric
Classical and Quantum Gravity, 1999Co-Authors: Michael Bradley, Gyula Fodor, László Á. Gergely, Mattias Marklund, Zoltán PerjésAbstract:Locally rotationally symmetric Perfect Fluid solutions of Einstein's gravitational equations are matched along the hypersurface of vanishing pressure with the NUT metric. These rigidly rotating Fluids are interpreted as sources for the vacuum exterior which consists only of a stationary region of the Taub-NUT spacetime. The solution of the matching conditions leaves generally three parameters in the global solution. Examples of Perfect Fluid sources are discussed.
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Rotating incompressible Perfect Fluid source of the NUT metric
arXiv: General Relativity and Quantum Cosmology, 1998Co-Authors: László Á. Gergely, Zoltán Perjés, Gyula FodorAbstract:A global solution of the Einstein equations is given, consisting of a Perfect Fluid interior and a vacuum exterior. The rigidly rotating and incompressible Perfect Fluid is matched along the hypersurface of vanishing pressure with the stationary part of the Taub-NUT metric. The Fluid core generates a negative-mass NUT space-time. The matching procedure leaves one parameter in the global solution.
Ernani Ribeiro - One of the best experts on this subject based on the ideXlab platform.
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static Perfect Fluid space time on compact manifolds
Classical and Quantum Gravity, 2020Co-Authors: F Coutinho, R Diogenes, B Leandro, Ernani RibeiroAbstract:The purpose of this article is to investigate the geometry of static Perfect Fluid space-time metrics on compact manifolds with boundary. In the first part, we provide a boundary estimate for static Perfect Fluid space-time. In the second part, we establish a unified B\"ochner type formula for a large class of spaces that include the static Perfect Fluid space-time, critical metrics of the volume functional, static spaces and CPE metrics. Moreover, as a consequence of such a formula we obtain a gap result for a compact static Perfect Fluid space-time.
