External gravitational field of a non-static spherically symmetric body

It is shown that in the field theory of gravitation, the external gravitational field of a non-static spherically symmetric source described by a diagonal metric tensor can be static only.     

The gravitational field of static spherically symmetric bodies

The study of a previously proposed theory of gravitation [Petry, W. (1979).Gen. Rel. Grav.,10, 599; (1981).Ibid,13, 865] is continued. The field equations are given in a simple covariant form. For a perfect fluid with pressure the static spherically symmetric solutions of the gravitation theory are studied. Inertial and gravitational mass are identical. The solutions agree with the corresponding results of the theory of general relativity up to high order in the coupling constant. Under some natural conditions the solutions of a static spherically symmetric body are not singular.     

The electrostatic and gravitational field of spherically symmetric objects

The electrostatic and gravitational fields of an extended spherically symmetric object is presented. The limit to a point-like object is discussed for Born-Infeld type of electrodynamics and it is shown, that the extreme Reissner-Nordstrøm field, where no event horizon occurs, is unphysical.     

Neutrino oscillations in the general spherically symmetric gravitational field

The results for neutrino oscillations in the gravitational field described by the Schwarzschild metric are generalized to the general spherically symmetric gravitational field.     

Generation and construction of statistical spherically symmetric solutions of the gravitational equations

We show that the possibility of reducing the Einstein equations in isotropic Bondi coordinates for a spherically symmetric statistical case to two forms of a linear differential equation allows one to introduce procedures for generating a fortiori exact solutions of the gravitational equations from the known ones. A superposition of solutions is defined in a special way. Examples are given of the known solutions obtained in this way from flat space-time. The use of the proposed generating procedures allows one to find all exact solutions of the gravitational equations for neutral sources in the statistical, spherically symmetric case.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 5–9, June, 1990.     

Singularities in solutions of the Einstein equations for a static spherically symmetric field

Russian Physics Journal - The nature of the singularities in the solutions of Einstein's equations for a static spherically symmetric field is investigated as a function of the choice of...     

Equations of motion of test bodies in a spherically symmetric,static gravitational field

We consider a class of theories of gravity in which the motion of test particles is governed by the path equation (with respect to a general affine connection Г). When we restrict attention to a spherically symmetric, static gravitational field, the path equation is characterized by three arbitrary functions of the gravitational field (as opposed to two in the case of metric theories where Г={ }). We find that there are essentially only two constraints on the three functions by appealing to solar system experiments. Therefore, we must supplement the equation of motion with other physical laws to obtain a value for the third arbitrary function (this, of course, is not necessary in the case of metric theories). If we consider theories in which both Г andg play a physical role we find in certain circumstances that this “third” condition is sufficient to prove that the theories under investigation reduce to their “metric” form.     

A spherically symmetric gravitational collapse-field with radiation

An interior spherically symmetric solution of Einstein’s field equations corresponding to perfect fluid plus a flowing radiation-field is presented. The physical 3-spacet=constant of our solution is spheroidal. Vaidya’s pure radiation field is taken as the exterior solution. The inward motion of the collapsing boundary surface follows from the equations of fit. An approximation procedure is used to get a generalization of the standard Oppenheimer-Snyder model of collapse with outflow of radiation. One such explicit solution has been given correct to second power of eccentricity of the spheroidal 3-space.     

静态球对称引力场中光线偏折的几何算法

光线的引力偏折和光在介质中的折射有统一的地方,本文采用几何光学的方法讨论星光掠过太阳时的偏折角度,所得结果和经典文献一致.     

Exact solutions for the spherically symmetric vacuum field in the general scalar tensor theory

A conformai technique is given for the generation of exact solutions for the spherically symmetric vacuum field in the general Bergmann-Wagoner-Nordtvedt scalar-tensory theory with vanishing cosmological constant. We discuss in particular the solution for Schwinger's theory and for models with ⁿ coupling or with curvature coupling. It appears that all theories with vanishing cosmological term lead to the presence of naked singularities.     

The gravitational field of spherically symmetric matter distributions in the Yang-Mills gauge theory of gravity

In the new SO(1,3)-gauge theory of gravity, the exterior gravitational field of any spherically symmetric equilibrium distribution of matter and non-gravitational force fields is determined by two parameters, the gravitational mass M and the structure parameter γ. We discuss the physical interpretation of the parametrized post-Newtonian parameter γ in this theory of gravity. The boundary conditions fix uniquely the values of M and γ; it turns out that γ ? 1 is a measure for the gravitational binding of the source. In the Newtonian limit, stars with negligible radiation pressure are characterized by $\text{γ=1?}\text{2}\text{3}\text{M}\text{R}$, while radiation-dominated stellar structures may even have γ > 1; the value of γ for tightly bound neutron stars of one solar mass is about 0.9.     

Shear-free spherically symmetric solutions with conformal symmetry

Dyer, McVittie and Oattes (1987) presented the field equations for shearfree perfect fluid spacetimes which are spherically symmetric and admit a conformal symmetry. Two special solutions of these equations are found. Furthermore, in the general case, one field equation is solved in terms of a Painlevé transcendent, while the remaining equation is reduced to an Emden-Fowler equation.     

Local Hamiltonian for spherically symmetric gravity coupled to a scalar field

We present a gauge fixing of gravity coupled to a scalar field in spherical symmetry such that the Hamiltonian is an integral over space of a local density. Such a formulation had proved elusive over the years. As in any gauge fixing, it works for a restricted set of initial data. We argue that the set could be large enough to attempt a quantization the could include the important case of an evaporating black hole.