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1.
The field equations of Barber's (1982) second self-creation theory of gravitation are solved for 5D Friedmann-Robertson-Walker
space time using perfect fluid energy momentum tensor. By assuming an equation of state p= ε ρ, (0 ≤ ε ≤ 1), the solutions of the field equations, in different scenarios, in Barber's second self-creation theory
are presented and discussed. Some properties of these models are also discussed. 相似文献
2.
Spatially-homogeneous and anisotropic Bianchi type-I cosmological models are obtained, in Barber's second self-creation theory of gravitation, when the source of the gravitational field is a perfect fluid. Some physical and geometrical properties of the models are discussed. 相似文献
3.
Hugo Levato Stella Malaroda Beatriz García Nidia Morrell Gladys Solivella Monica Grosso 《Astrophysics and Space Science》1991,183(1):147-153
Spatially-homogenous and anisotropic Bianchi type-II and III cosmological models are obtained in Barber's second self-creation theory of gravitation both in vacuum and in the presence of perfect fluid with pressure equal to energy density. Some properties of the models are discussed. 相似文献
4.
Spatially-homogenous and anisotropic Bianchi type-VI0 cosmological models are obtained, in Barber's second self-creation theory of gravitation, both in vacuum and in the presence of perfect fluid with pressure equal to energy density. Some properties of the model are discussed. 相似文献
5.
An anisotropic, homogeneous Bianchi type-I cosmological micro model is obtained in Barber's modified theory of general relativity.
Some properties of the model are discussed. Further, it is found that this theory leads to Einstein theory as the coupling
parameterλ → 0 in micro level (i.e., quantum level) in general.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
6.
Totally anisotropic Bianchi type-II cosmological solutions are presented in Barber's second self-creation theory of gravitation
both in vacuum and in the presence of stiff-matter. The corresponding cosmological models have no finite singularity. The
stiff-matter model gives essentially an empty universe for large time. Some physical and kinematical properties of the models
are discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
7.
Vacuumk=0 Friedmann-type solutions in the continuous creation theory of gravitation proposed by Barber have recently been found by Reddy (1987). Here we obtain thek=±1 Friedmann solutions in Barber's theory. Also, we show that these models are, in fact, vacuum Brans-Dicke solutions that have been studied earlier by Lorenz-Petzold (1984). 相似文献
8.
A spatially homogeneous anisotropic Bianchi type-I cosmological model in the Barber's second self-creation theory is constructed
when the gravitational field is generated by a mixture of micro and macro matter fields represented by meson field and perfect
fluid respectively. The physical and geometrical features of the micro and macro cosmological model are discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
9.
Exact Bianchi-type VIII and IX models in the presence of Barber's second self-creation theory of cosmology are presented, when the source of the gravitational field is a perfect fluid withP=. Some physical and geometrical properties of the models are discussed. 相似文献
10.
In this paper, the problem of spatially homogeneous and an isotropic Bianchi type-1 space time with perfect fluid distribution
is considered in Barber's second theory of gravitation. To obtain determinate solutions, we have assumed the equation of statep= γρ, 0 ≤ γ ≤ 1. It is observed that the general fluid distribution degenerates isotropic vacuum model whenγ = 1 and Λ < 0.
Further it is observed that the vacuum model obtained in case of γ = 0, ρ = 0 andΛ = 0, reduces to well known Kasner model
in Einstein's theory. Some physical and geometrical aspects of the models together with singularities in the models are also
discussed
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
11.
Spatially homogeneous and isotropic Robertson-Walker model of the universe is studied in Barber's second self-creation theory of gravitation in the presence of perfect fluid by using gamma-law equation of state p =(-1). The parameter gamma varies continuously with cosmological time. Exact solutions of the field equations are obtained for inflationary period and radiation-dominated era by using the power law relation Rn-3 = B. Some physical properties of the models are also discussed. 相似文献
12.
An attempt has been made to solve the field equations with perfect fluid in an inhomogeneous space-time governed by the metric
in both Einstein and Barber's theories of gravitation. It is shown here that in both the theories the field equations are
reducible to a Laplace equation and the perfect fluid distribution does not survive. Moreover all the solutions represent
plane gravitational wave and the vacuum models in both the theories can be constructed by an arbitrary harmonic function iny and z coordinates.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
13.
李林森 《中国天文和天体物理学报》1997,(4)
利用双星自转同步性理论给出了６９个三类密近双星系统中９３个子星的临界同步自转参量和临界自转周期．并把利用临界自转同步参量所计算的临界自转周期与由气体星自转不稳定理论所计算的临界自转周期做了比较，其结果是两者均属同一量级． 相似文献
14.
15.
A form of planetary perturbation theory based on canonical equations of motion, rather than on the use of osculating orbital elements, is developed and applied to several problems of interest. It is proved that, with appropriately selected initial conditions on the orbital elements, the two forms of perturbation theory give rise to identical predictions for the observable coordinates and velocities, while the orbital elements themselves may be strikingly different. Differences between the canonical form of perturbation theory and the classical Lagrange planetary perturbation equations are discussed. The canonical form of perturbation theory in some cases has advantages when the perturbing forces are velocity-dependent, but the two forms of perturbation theory are equivalent if the perturbing forces are dependent only on position and not on velocity. The canonical form of the planetary perturbation equations are derived and applied to the Lense Thirring precession of a test body in a Keplerian orbit around a rotating mass source. 相似文献
16.
A. I. Shapiro 《Astrophysics》2002,45(2):215-222
A model problem in the theory of line formation in an optically thick, purely scattering, stellar atmosphere is considered. The integral equation of radiation transfer at line frequencies is solved numerically for a two-level atom in the approximation of complete frequency redistribution in scattering. The numerical results are compared with those calculated from equations of the asymptotic theory. On the basis of the asymptotic theory, the positions of intensity maxima in a line are found for different absorption profiles. 相似文献
17.
The Newtonian theory of gravitation is modified to include the gravitational energy as a source of gravitational potential,
thus making the theory self-coupled and nonlinear. The modified theory can be derived from a Lorentz-invariant action principle.
The Kepler problem is discussed in this theory and it is shown that the perihelion of the orbit steadily precesses. The rate
of precession is, however, insufficient to account for the observed precession of the perihelion of Mercury. The differences
from the Newtonian theory for the bending of light and the gravitational redshift of spectral lines are shown to be marginal. 相似文献
18.
Luni-solar perturbations of an Earth satellite 总被引：1，自引：0，他引：1
A. E. Roy 《Astrophysics and Space Science》1969,4(4):375-386
Luni-solar perturbations of the orbit of an artificial Earth satellite are given by modifying the analytical theory of an artificial lunar satellite derived by the author in recent papers. Expressions for the first-order changes, both secular and periodic, in the elements of the geocentric Keplerian orbit of the earth satellite are given, the moon's geocentric orbit, including solar perturbations in it, being found by using Brown's lunar theory.The effects of Sun and Moon on the satellite orbit are described to a high order of accuracy so that the theory may be used for distant earth satellites. 相似文献
19.
Vladimír Majerník 《Astrophysics and Space Science》1985,113(1):199-203
In the framework of Rastall's conservative program for the construction of gravitation theory we present a variant of modified classical gravitation theory based on Einstein's energy-mass equivalence principle. We pursue further the special-relativistic arguments and obtain a theory for the static spherically-symmetric gravitation field that is based only on the well-established physical principles and accounts for all experimental tests known in gravitation. Some astrophysical consequences of the modified classical gravitation theory (e.g., the non-existence of black holes, the creation of real particles in a strong gravitation field) are also discussed. 相似文献
20.
1引言尽管有诸多的不满之处,由于其物理上的直观性和应用上的简单性,至今混合长理论仍几乎是唯一一个广泛用于恒星结构、演化和脉动计算的恒星对流理论.混合长理论预言,在红、黄巨星和超巨星大气中,对流是超声速的.我们曾指出,混合长理论隐含了一个假定,对流是亚声速的.对于超声速对流,无论从物理的真实性,还是从混合长公式的数学表述来看,混合长理论都是不正确的.因此超声对流的真实性是存在问题 相似文献