共查询到20条相似文献,搜索用时 0 毫秒
1.
We study spherically symmetric inhomogeneous cosmological model with heat flow in higher dimensional space-time and present
a class of solutions in which the velocity field is shear-free. Some of these solutions are analogous to the known solutions
in 4-dimension while some are totally new. 相似文献
2.
Spherically symmetric solution in higher-dimensional teleparallel equivalent of general relativity 下载免费PDF全文
Gamal G.L.Nashed 《中国物理 B》2013,22(2):20401-020401
A theory of(N+1)-dimensional gravity is developed on the basis of the teleparallel equivalent of general relativity(TEGR).The fundamental gravitational field variables are the(N+1)-dimensional vector fields,defined globally on a manifold M,and the gravitational field is attributed to the torsion.The form of Lagrangian density is quadratic in torsion tensor.We then give an exact five-dimensional spherically symmetric solution(Schwarzschild(4+1)-dimensions).Finally,we calculate energy and spatial momentum using gravitational energy-momentum tensor and superpotential 2-form. 相似文献
3.
The most general time-independent spherically symmetric (in the usual three space dimensions) solution to the five-dimensional vacuum Einstein equations is found, subject to the existence of a Killing vector in the fifth direction. The significance of these solutions is discussed within the context of a previously proposed extension of the Kaluza-Klein model in which the universe, although (4+1)-dimensional, has evolved over cosmic times into an effectively (3+l)-dimensional one. 相似文献
4.
R. J. van den Hoogen 《General Relativity and Gravitation》2008,40(10):2213-2227
Schwarzschild’s solution to the Einstein Field Equations was one of the first and most important solutions that lead to the
understanding and important experimental tests of Einstein’s theory of General Relativity. However, Schwarzschild’s solution
is essentially based on an ideal theory of gravitation, where all inhomogeneities are ignored. Therefore, any generalization
of the Schwarzschild solution should take into account the effects of small perturbations that may be present in the gravitational
field. The theory of Macroscopic Gravity characterizes the effects of the inhomogeneities through a non-perturbative and covariant
averaging procedure. With similar assumptions on the geometry and matter content, a solution to the averaged field equations
as dictated by Macroscopic Gravity are derived. The resulting solution provides a possible explanation for the flattening
of galactic rotation curves, illustrating that Dark Matter is not real but may only be the result of averaging inhomogeneities
in a spherically symmetric background. 相似文献
5.
Chris Vuille 《General Relativity and Gravitation》2007,39(5):621-632
The Klein–Gordon equations are solved for the case of a plane-symmetric static massless scalar field in general relativity
with cosmological constant, generalizing the solutions found by Taub, Novotny and Horsky, and Singh. A separate class of solutions
is obtained in which the metrics reduce to flat space in the limit that .The static solutions can be used to generate time-dependent cosmological solutions, one of which exhibits rapid inflation
followed by continued exponential expansion at all later times. 相似文献
6.
D C Srivastava 《Pramana》1989,32(6):741-748
A method to obtain exact solutions characterizing spherically symmetric charged perfect fluid distributions undergoing shear-free
motion has been discussed. This method makes use of the criterion that the solution be free from movable critical points as
has been employed earlier by Shah and Vaidya. Two solutions have been obtained, one of which is new and the other is the recent
solution due to Sussman. 相似文献
7.
A.B. Arbuzov B.M. Barbashov R.G. Nazmitdinov V.N. Pervushin A. Borowiec K.N. Pichugin A.F. Zakharov 《Physics letters. [Part B]》2010
The General Relativity formulated with the aid of the spin connection coefficients is considered in the finite space geometry of similarity with the Dirac scalar dilaton. We show that the redshift evolution of the General Relativity describes the vacuum creation of the matter in the empty Universe at the electroweak epoch and the dilaton vacuum energy plays a role of the dark energy. 相似文献
8.
A magnetized cylindrically symmetric universe with two degrees of freedom in which the free gravitational field is Petrov
type I degenerate, is obtained. The magnetic field is due to an electric current produced along the x-axis. The distribution
consists of an electrically neutral perfect fluid with an infinite electrical conductivity. The behaviour of the model when
magnetic field tends to zero and other physical aspects of the model are also discussed. 相似文献
9.
Five-dimensional teleparallel theory equivalent to general relativity, the axially symmetric solution, energy and spatial momentum 下载免费PDF全文
Gamal G.L. Nashed 《中国物理 B》2011,20(11):110402-110402
A theory of (4+1)-dimensional gravity is developed on the basis of the teleparallel theory equivalent to general relativity. The fundamental gravitational field variables are the five-dimensional vector fields (pentad), defined globally on a manifold M, and gravity is attributed to the torsion. The Lagrangian density is quadratic in the torsion tensor. We then give the exact five-dimensional solution. The solution is a generalization of the familiar Schwarzschild and Kerr solutions of the four-dimensional teleparallel equivalent of general relativity. We also use the definition of the gravitational energy to calculate the energy and the spatial momentum. 相似文献
10.
A solution of the Einstein-Maxwell equations corresponding to source-free electromagnetic field plus pure radiation is obtained.
The solution is algebraically special. A particular case of the solution is considered which encompasses many known solutions.
Among them is a radiating Ruban metric. 相似文献
11.
Carlos N. KozamehEzra T. Newman Savitri V. Iyer 《Journal of Geometry and Physics》1992,8(1-4):195-209
The field equations for two non-local variables, equivalent to the Einstein vacuum equations, are presented. These variables are the holonomy operator associated with special paths and the light cone cut function.
Starting from these equations, one shows via a perturbation argument that a single, fourth-order equation for the cut function can be derived. This single equation encodes the entire conformal structure of a vacuum space—time. The same perturbation technique yields, via quadratures, solutions to the vacuum Einstein equations to any order. 相似文献
12.
Mendel Sachs 《Foundations of Physics Letters》1988,1(2):163-169
Inertial mass in relativity theory is discussed from a conceptual view. It is shown that though relativistic dynamics implies a particular dependence of the momentum of a free particle on its velocityin special relativity, which diverges as v approaches c, the inertial mass itself of a moving body remains constant, from any frame of observation. However, extension to general relativity does conceptually introduce variability of the inertial mass of a body, through a necessarily generally covariant field theory of inertia, when the Mach principle is incorporated into the theory of general relativity, as a theory of matter. 相似文献
13.
This paper illustrates the value of the Newman—Penrose complex null tetrad formalism by using it to obtain all algebraically special Einstein spaces admitting three-parameter groups of motions acting on timelike surfaces containing the repeated principal null direction. Taken together with earlier work, this enables us to give a complete list of Einstein spaces which are both algebraically special and hypersurface-homogeneous or homogeneous. 相似文献
14.
In this paper, we have investigated Bianchi type I inflationary universe in the presence of massless scalar field with a flat
potential. To get an inflationary solution, we have considered a flat region in which potential V is constant. The inflationary scenario of the model is discussed in detail. 相似文献
15.
16.
This is a summary of the presentations at the parallel session in the classical general relativity workshop of the ICGC-2004. 相似文献
17.
A R Prasanna 《Pramana》1991,36(5):445-488
In this we briefly review the discussions on accretion dynamics, the standard scenario and the ones including the effects
of electromagnetic fields. The emphasis throughout is to show the relevance of general relativistic formalism in discussing
the dynamics of magnetofluid around compact objects. 相似文献
18.
Static spherically symmetric solutions have been obtained for general projective relativity withn=0 andn0 both in isotropic and curvature coordinates. In curvature coordinates, only a restricted exact solution is possible. However, an approximate solution can always be obtained following a method similar to Vanden Bergh. In these spacetimes there is no horizon, but only a naked singularity atr=0. Thus there are no black holes. It is shown that there is no solution in static, spherically symmetric, conformally flat spacetime. 相似文献
19.
An exact solution is obtained for coupled dilaton and electromagnetic field in a cylindrically symmetric spacetime where an
axial magnetic field as well as a radial electric field both are present. Depending on the choice of the arbitrary constants
our solution reduces either to dilatonic gravity with pure electric field or to that with pure magnetic field. In the first
case we have a curvature singularity at a finite distance from the axis indicating the existence of the boundary of a charged
cylinder which may represent the source of the electric field. For the second case we have a singularity on the axis. When
the dilaton field is absent the electromagnetic field disappears in both the cases. Whereas the contrary is not true. It is
further shown that light rays except for those proceeding in the radial direction are either trapped or escape to infinity
depending on the magnitudes of certain constant parameters as well as on the nature of the electromagnetic field. Nature of
circular geodesics is also studied in the presence of dilaton field in the cylindrically symmetric spacetime. 相似文献
20.
文章介绍了爱因斯坦建立相对论,特别是广义相对论的伟大贡献。爱因斯坦提出了光速不变原理、广义相对性原理、马赫原理和等效原理。他不仅首先指出万有引力本质上是时空弯曲的几何效应,而且首先给出了广义相对论的基本方程。文章还讨论了为什么爱因斯坦是狭义相对论和广义相对论的唯一创建者。 相似文献