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1.
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
2.
Classification of all electrovac specetimes permitting the separation of variables in the Hamilton-Jacobi equation for a charged
test particle is carried out. This separation requires the existence of a complete set consisting of Killing’s vectors and
tensors of a special kind. Every complete set defines its own type of metric and electromagnetic potential in the separable
coordinate system. There exist seven types of separation of variables for electromagnetic spaces. For every type an additional
classification is carried out by transformation of coordinates without any disturbance of the separation conditions, the gradient
transformation of electromagnetic potential and the conformal-constant transformation of metric.
The key step in solving the problem is the extraction of an autonomous subsystem which determines the metric from only the
Einstein-Maxwell equations for every type of separation of variables.
Representatives of all classes of metrics and electromagnetic potential are given for every type of separation of variables
with the exception of the spaces found in the well-known work by Carter.
The problem is solved in terms of metric formalism. The classes of electrovac spacetimes obtained are found to be related
to Petrov’s classification. 相似文献
3.
Wenbiao Han 《General Relativity and Gravitation》2008,40(9):1831-1847
We study chaos dynamics of spinning particles in Kerr spacetime of rotating black holes use the Papapetrou equations by numerical
integration. Because of spin, this system exists many chaos solutions, and exhibits some exceptional dynamic character. We
investigate the relations between the orbits chaos and the spin magnitude S, pericenter, polar angle and Kerr rotation parameter a by means of a kind of brand new Fast Lyapulov Indicator (FLI) which is defined in general relativity. The classical definition
of Lyapulov exponent (LE) perhaps fails in curve spacetime. And we emphasize that the Poincaré sections cannot be used to
detect chaos for this case. Via calculations, some new interesting conclusions are found: though chaos is easier to emerge
with bigger S, but not always depends on S monotonically; the Kerr parameter a has a contrary action on the chaos occurrence. Furthermore, the spin of particles can destroy the symmetry of the orbits
about the equatorial plane. And for some special initial conditions, the orbits have equilibrium points. 相似文献
4.
We discuss transformation laws of electric and magnetic fields under Lorentz transformations, deduced from the classical field
theory. It is found that we can connect the resulting expression for a bivector formed with those fields, with the expression
deduced from the Wigner transformation rules for spin-1 functions of massive particles. This mass parameter should be interpreted because the constancy of speed of light forbids the existence of the
photon mass. 相似文献
5.
Valeri V. Dvoeglazov 《Foundations of Physics Letters》1997,10(4):383-391
It is shown that the Evans-Vigier modified electrodynamics is compatible with relativity theory. 相似文献
6.
分析了在相对论体系中狭义相对性原理和宇宙学原理之间的关系以及Beltrami-de Sitter -陆启铿疑难.指出可以把狭义相对性原理推广到非零常曲率时空,在具有Beltrami度规 的de Sitter/反de Sitter时空中建立狭义相对论的运动学和粒子动力学. 在这类狭义相对 论中,相对于Beltrami坐标同时性,Beltrami坐标系就是惯性坐标系,相应的观测者为惯 性观测者; 对于自由粒子和光讯号, 惯性定律成立;可以定义可观测量,它们不但守恒而且还 满足推广的爱因斯坦关系.除了Beltrami坐标时同时性之外,对于共动观测, 还可以取固 有时同时性;此时,Beltrami度规成为Robertson-Walker型的度规,其3维空间是闭的,对 于平坦的偏离为宇宙学常数的量级.这表明,在这类狭义相对论中,相对性原理与“完美”宇 宙学原理之间存在内在联系,并不存在那些问题.进而,基于最新观测事实,重述了Mach原 理;指出对于Beltrami-de Sitter/反de Sitter时空,宇宙学常数恰恰给出惯性运动的起 源.
关键词:
狭义相对性原理
宇宙学原理
de Sitter不变的狭义相对论
Beltrami-de Sitter时空
同时性
Mach原理 相似文献
7.
In flat spacetime, the fourth space coordinate in special relativity (SR) is equivalent to the coordinate time tE. We will show, however, that this definition of physical time is not unique. Another natural choice of coordinate time, tA, with absolute synchronization is allowed. Spacetime would exhibit dual properties, namely relativistic and absolute. In an arbitrary inertial frame, the relationship of the above two kinds of coordinate time corresponds to a resynchronization, and the Lorentz transformations can be written in an alternative form, which is called the generalized Galilean transformation (GGT). Although the absolute property is still hidden in nearly all types of experiments, the advantages of the above approach are as follows: (1) It will give us a deeper understanding of SR, including the basis of length contraction, time dilation and the interaction between moving objects and the physical vacuum. (2) It will provide a wider research domain than SR; for example, superluminal motion is predicted and has obtained growing experimental support. 相似文献
8.
9.
By assuming "p = Aρ" and the total intrinsic energy density εrk (k + D - 1 > 0), we strictly solve the higher dimensional Einstein-Maxwell field equations in a static charged sphere, resulting in an exact interior solution of the equations. 相似文献
10.
S. Mignemi 《Annalen der Physik》2010,522(12):924-940
We discuss the generalization of Doubly Special Relativity to a curved de Sitter background. The model has three fundamental observer‐independent scales, the velocity of light c, the de Sitter radius α, and the Planck energy κ, and can be realized through a nonlinear action of the de Sitter group on a noncommutative position space. We consider different choices of coordinates on the de Sitter hyperboloid that, although equivalent, may be more suitable for treating different problems. Also the momentum space can be described as a hyperboloid embedded in a five‐dimensional space, but in this case different choices of coordinates lead to inequivalent models. We investigate the kinematics and the Hamiltonian dynamics of some specific models and describe some of their phenomenological consequences. Finally, we show that it is possible to construct a model exhibiting a duality for the interchange of positions and momenta together with the interchange of α and κ. 相似文献
11.
Three exact non-static solutions of Einstein-Maxwell equations corresponding to a field of flowing null radiation plus an
electromagnetic field are presented. These solutions are non-static generalizations of the well known Kerr-Newman solution.
The current vector is null in all the three solutions. These solutions are the electromagnetic generalizations of the three
generalized radiating Kerr solutions discussed by Vaidya and Patel. The solutions discussed by us describe the exterior gravitational
fields of rotating radiating charged bodies. Many known solutions are derived as particular cases. 相似文献
12.
The equation is the charged generalization of the Emden-Fowler equation that is crucial in the study of spherically symmetric shear-free spacetimes. This version arises from the Einstein–Maxwell system for a charged shear-free matter distribution. We integrate this equation and find a new first integral. For this solution to exist, two integral equations arise as integrability conditions. The integrability conditions can be transformed to nonlinear differential equations, which give explicit forms for and in terms of elementary and special functions. The explicit forms and arise as repeated roots of a fourth order polynomial. This is a new solution to the Einstein-Maxwell equations. Our result complements earlier work in neutral and charged matter showing that the complexity of a charged self-gravitating fluid is connected to the existence of a first integral. 相似文献
13.
14.
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
15.
提出了有限精度函数理论,并基于该理论求出了有限精度的Einstein-Maxwell方程的光子解,揭示了经典光子的电磁、引力与时空几何的重要性质.
关键词:
有限精度函数理论
Einstein-Maxwell方程
光子解 相似文献
16.
A non-static exact solution of Einstein’s equations corresponding to a field of flowing null radiation plus an electromagnetic
field is presented. The geometry of the solution is described by the Kerr-Schild metric. The solution admits a shear-free,
geodetic null congruence. It has the symmetry of the Kerr-Newman solution and when a certain parameter is put equal to zero
the solution becomes static and reduces to the Kerr-Newman solution. 相似文献
17.
采用在牛顿力学中常用的方法,用一种简洁的数学形式给出了一维运动情形下受恒力作用的粒子的相对论动力学方程的一个例解,详细讨论了相对论粒子的加速度、速度和运动方程与牛顿力学中对应物理量的区别和联系. 相似文献
19.
引进了实数的层次性与离散化,将连续函数理论加以改进和推广为离散函数理论,并基于由离散函数理论所表示的经典广义相对论来讨论尘埃物质的引力塌缩问题,指出了关于这个问题的连续体系的Oppenheimer 和Snyder解中的Friedmann内解与Schwarzschild外解的不完整性并加以拓展和离散化,导出了一种非塌缩的尘埃物质结构,消除了引力奇性并揭示了时空离散化的深刻性质.
关键词:
离散实数
离散时空
广义相对论
Oppenheimer 和Snyder解
奇性自由 相似文献
20.
We find a solution of the Einstein-Maxwell system of field equations for a class of accelerating, expanding and shearing spherically
symmetric metrics. This solution depends on a particularansatz for the line element. The radial behaviour of the solution is fully specified while the temporal behaviour is given in terms
of a quadrature. By setting the charge contribution to zero we regain an (uncharged) perfect fluid solution found previously
with the equation of statep = μ + constant, which is a generalisation of a stiff equation of state. Our class of charged shearing solutions is characterised
geometrically by a conformal Killing vector. 相似文献