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1.
On the basis of the results by Huang et al. (1990), this paper further discusses and analyses the four post-Newtonian effects in a near-Earth satellite orbit: the Schwarzschild solution, the post-Newtonian effects of the geodesic precession, the Lense-Thirring precession and the oblateness of the Earth. A full analytical solution to the effects including their direct perturbations and mixed perturbations due to the Newtonian oblateness (J
2) perturbation and the Schwarzschild solution is obtained using the quasi-mean orbital element method analogous to the Kozai's mean orbital element one. Some perturbation properties of the post-Newtonian effects are revealed. The results obtained not only can provide a sound scientific basis for the precise determination of a man-made satellite orbit but also is suitable for similar mechanics systems, such as the motions of planets, asteroids and natural satellites. 相似文献
2.
We consider a collapsing sphere and discuss its evolution under the vanishing expansion scalar in the framework of f(R) gravity. The fluid is assumed to be locally anisotropic which evolves adiabatically. To study the dynamics of the collapsing
fluid, Newtonian and post Newtonian regimes are taken into account. The field equations are investigated for a well-known
f(R) model of the form R+δR
2 admitting Schwarzschild solution. The perturbation scheme is used on the dynamical equations to explore the instability conditions
of expansionfree fluid evolution. We conclude that instability conditions depend upon pressure anisotropy, energy density
and some constraints arising from this theory. 相似文献
3.
Neeraj Pant 《Astrophysics and Space Science》2011,331(2):633-644
We present three new categories of exact and spherically symmetric Solutions with finite central parameters of the general
relativistic field equations. Two well behaved solutions in curvature coordinates first category are being studied extensively.
These solutions describe perfect fluid balls with positively finite central pressure, positively finite central density; their
ratio is less than one and causality condition is obeyed at the centre. The outmarch of pressure, density, pressure-density
ratio and the adiabatic speed of sound is monotonically decreasing for these solutions. Keeping in view of well behaved nature
of these solutions, one of the solution (I1) is studied extensively. The solution (I1) gives us wide range of Schwarzschild parameter u (0.138≤u≤0.263), for which the solution is well behaved hence, suitable for modeling of Neutron star. For this solution the mass of
Neutron star is maximized with all degree of suitability and by assuming the surface density ρ
b
=2×1014 g/cm3. Corresponding to u=0.263, the maximum mass of Neutron star comes out to be 3.369 M
Θ with linear dimension 37.77 km and central and surface redshifts are 4.858 and 0.4524 respectively. We also study some well
known regular solutions (T-4, D-1, D-2, H, A, P) of Einstein’s field equations in curvature coordinates with the feature of
constant adiabatic sound speed. We have chosen those values of Schwarzschild parameter u for which, these solutions describe perfect fluid balls realistic equations of state. However, except (P) solution, all these
solutions have monotonically non-decreasing feature of adiabatic sound speed. Hence (P) solution is having a well behaved
model for uniform radial motion of sound. Keeping in view of well behaved nature of the solution for this feature and assuming
the surface density; ρ
b
=2×1014 g/cm3, the maximum mass of Neutron star comes out to be 1.34 M
Θ with linear dimension 28.74 km. Corresponding central and surface redshifts are 1.002 and 0.1752 respectively. 相似文献
4.
Gamal G. L. Nashed 《Astrophysics and Space Science》2011,335(2):593-598
We give a class of spherically symmetric-Anti de Sitter (Ads), exact solution in the teleparallel equivalent of general relativity
(TEGR). The solution depends on an arbitrary function F(R)\mathcal{F}(R) and reproduce the metric of Schwarzschild Ads space-time. In the context of the Hamiltonian formulation of the TEGR we compute
the gravitational energy of this class. The calculation is carried out by means of an expression for the energy of the gravitational
field that naturally arises from the integral form of the constraint equations of the formalism. We show that the form of
the energy depends on the arbitrary function. We make a constrain on this arbitrary function to give the correct form of energy. 相似文献
5.
Solutions of field equations of the generalized theory of gravitation for neutral and charged point masses are found. The problem is formulated so that the solution may be expressed in harmonic, isotropic, Schwarzschild and, if necessary, any other coordinates. A method for the solution of the static axisymmetric problem (an analogue of a well-known Weyl's solution) is also proposed. 相似文献
6.
S. I. Chermyanin 《Astrophysics and Space Science》1992,197(2):233-235
A new type of a solution of the Schwarzschild problem for a point particle has been obtained. In contrast to the standard forms of solutions, the Schwarzschild singularity in the given solution coincides with the central singularity. 相似文献
7.
A.F. Zakharov 《Astronomische Nachrichten》2002,323(6):538-541
We discuss basic ideas which were fundamental for the black hole concept. The major goal of the historical part is an attempt to explain the long way to the birth of the black hole concept, since the black hole solution was already found in 1916 by K. Schwarzschild, but the black hole concept was only introduced in 1967 by J.A. Wheeler. We discuss the basic notations of the black hole theory and observational manifestations of black holes. We analyse the possibility to interpret the very peculiar distortion of the Fe Kα‐line in such a way. 相似文献
8.
In this paper, we study quantum corrections to the temperature and entropy of a regular Ayón-Beato-García-Bronnikov black
hole solution by using tunneling approach beyond semiclassical approximation. We use the first law of black hole thermodynamics
as a differential of entropy with two parameters, mass and charge. It is found that the leading order correction to the entropy
is of logarithmic form. In the absence of the charge, i.e., e=0, these corrections approximate the corresponding corrections for the Schwarzschild black hole. 相似文献
9.
Ngangbam Ishwarchandra N. Ibohal K. Yugindro Singh 《Astrophysics and Space Science》2014,353(2):633-639
In this paper we present an exact solution of Einstein’s field equations describing the Schwarzschild black hole in dark energy background. It is also regarded as an embedded solution that the Schwarzschild black hole is embedded into the dark energy space producing Schwarzschild-dark energy black hole. It is found that the space-time geometry of Schwarzschild-dark energy solution is non-vacuum Petrov type D in the classification of space-times. We study the energy conditions (like weak, strong and dominant conditions) for the energy-momentum tensor of the Schwarzschild-dark energy solution. We also find that the energy-momentum tensor of the Schwarzschild-dark energy solution violates the strong energy condition due to the negative pressure leading to a repulsive gravitational force of the matter field in the space-time. It is shown that the time-like vector field for an observer in the Schwarzschild-dark energy space is expanding, accelerating, shearing and non-rotating. We investigate the surface gravity and the area of the horizons for the Schwarzschild-dark energy black hole. 相似文献
10.
11.
Henning Knutsen 《Astrophysics and Space Science》1989,162(2):315-336
An exact solution of Einstein's equations for a static isentropic perfect fluid sphere is examined in detail. The analysis yields a strong indication that the model isstable with respect to infinitesimal radial pulsations. This means that the temperature is decreasing outwards. We prove that the adiabatic speed of sound is everywhere less than the speed of light if and only if the radius of the sphere is larger than 1.61 times its Schwarzschild radius. We further show that the strong energy condition is fulfilled everywhere if and only if the radius is larger than 1.76 times the Schwarzschild radius. The necessary and sufficient condition for the speed of sound to be decreasing outwards is given, and we find that this criterion is fulfilled if the fluid is causal. Taking the values of the pressure and the density to be somewhere given by the maximum values from Baymet al.'s equation of state, i.e., 0=5.1×1014 g cm–3 andp
0=7.4×1033 dyne cm–2, we find the maximum mass of the fluid sphere to be 2.5 solar masses.Dedicated to the memory of the late George Cunliffe McVittie (1904–1988). 相似文献
12.
R. Broucke 《Astrophysics and Space Science》1971,12(2):366-377
A method of solution of the equations of planetary motion is described. It consists of the use of numerical general perturbations in orbital elements and in rectangular coordinates. The solution is expanded in Fourier series in the mean anomaly with the aid of harmonic analysis and computerized series manipulation techniques. A detailed application to the relativistic motion of the planet Mercury is described both for Schwarzschild and isotropic coordinates.Receipt delayed by the postal strike in Great Britain. 相似文献
13.
本文介绍五维广义相对论及Schwarzschild外部解,然后推导Schwarzschild内部解,最后着重采用五维引力理论计算水星近日点进动,光线在太阳附近的偏折,无线电信号延迟三个问题。结果表明,在现在实验条件下,五维理论对四维理论的修正是极其微小的,在与宇宙年龄相比拟情况下,两个理论的差别能显示出来。 相似文献
14.
The problem of determining the gravitational field of a static, spherically symmetric, self-gravitating object is formulated. The small number of physically applicable exact solutions of the equations in Jordan—Brans—Dicke theory is augmented with new exact solutions describing the external gravitational field of the given body. Once a solution has been found, it can be rewritten in modified curvature, homogeneous, and other coordinates by appropriate gauging. In a special case the solution coincides with the well-known Schwarzschild solution.Translated from Astrofizika, Vol. 37, No. 2, pp. 339–350, April–June, 1994.The authors are grateful to members of seminars convened by the Theoretical Physics Department of Erevan State University and the Space, Time, and Gravitation LTF of the Joint Institute for Nuclear Research for discussions.This work has received partial support from a Meyer Foundation Grant awarded by the American Physical Society. 相似文献
15.
We analyse the Schwarzschild solution in the context of the historical development of its present use, and explain the invariant definition of the Schwarzschild's radius as a singular surface, that can be applied to the Kerr‐Newman solution too. 相似文献
16.
In this paper we consider the equilibrium of a magnetofluid disc in Schwarzschild background with an external magnetic field,
having the azimuthal and the radial components of the flow velocity nonzero. The electrical conductivityσ of the fluid is taken to be finite and thus the solution for the electromagnetic field is required to satisfy the Ohm’s law
too with the four-current having onlyJ
ϕ andJ
t nonzero. The various physical parameters that have to correlate for possible equilibrium configurations are identified and
their respective magnitudes estimated. It is found that for a given angular momentum distribution the inner edge of the disc
can reach well within the usual6m limit only when the surface magnetic field of the central object is not too high when the matter density at the outer edge
of the disc and the accretion rate are taken with reasonable limits 相似文献
17.
I. I. Salukvadze 《Astrophysics and Space Science》1994,215(2):159-165
The electromagnetic radiation process of a Schwarzschild black hole moving in the nonuniform magnetic field is investigated. The total flux of radiation was obtained. A theoretical calculation has been carried out under the test magnetic field assumption, i.e., energy-momentum tensor does not disturb Schwarzschild background metric. The technique of the Teukolsky equation has been used. The Greens function from the low-frequency solution following Starobinsky and Churilov (1973) has been derived. It was found that black hole radiates nearly 60 per cent of conducting sphere under the same conditions. 相似文献
18.
B. Kuchowicz 《Astrophysics and Space Science》1975,33(1):L13-L14
A new exact solution of Einstein's equations is derived, which constitutes a generalization of the well-known internal Schwarzschild solution, and may be applied to relativistic spheres with a finite density increase toward the centre. 相似文献
19.
The so called gamma metric corresponds to a two‐parameter family of axially symmetric, static solutions of Einstein's equations found by Bach. It contains the Schwarzschild solution for a particular value of one of the parameters, that rules a deviation from spherical symmetry. It is shown that there is invariantly definable singular behaviour beyond the one displayed by the Kretschmann scalar when a unique, hypersurface orthogonal, timelike Killing vector exists. In this case, a particle can be defined to be at rest when its world‐line is a corresponding Killing orbit. The norm of the acceleration on such an orbit proves to be singular not only for metrics that deviate from Schwarzschild's metric, but also on approaching the horizon of Schwarzschild metric itself, in contrast to the discontinuous behaviour of the curvature scalar. 相似文献
20.
Mahamat Saleh Bouetou Bouetou Thomas Timoleon Crepin Kofane 《Astrophysics and Space Science》2014,350(2):721-726
In this paper, we evaluate quasinormal modes (QNMs) of scalar perturbations around a quantum-corrected Schwarzschild black hole by using the third order Wentzel-Kramers-Brillouin (WKB) approximation method. The results show that due to the quantum fluctuations in the background of the Schwarzschild black hole, the QNMs of the black hole damp more slowly when increasing the quantum correction factor (a), and oscillate more slowly. 相似文献