The researches of A. A. Fridman on the Einstein theory of gravitation

1963 ◽  
Vol 80 (7) ◽  
pp. 353-356 ◽  
Author(s):  
V.A. Fok
Keyword(s):  
Einstein Theory ◽  
Theory Of Gravitation

A new theory of gravitation

1964 ◽  
Vol 282 (1389) ◽  
pp. 191-207 ◽  
Keyword(s):  
Present Theory ◽  
Field Equations ◽  
Einstein Theory ◽  
Tests Of General Relativity ◽  
Know How ◽  
Theory Of Gravitation ◽  
The Mean ◽  
Usual Theory ◽  
Number Of Particles

A new theory of gravitation is developed. The theory is equivalent to that of Einstein in the description of macroscopic phenomena, and hence the situation is the same so far as the classical tests of general relativity are concerned. The new theory differs in its global implications, however. There are two main differences of principle. In the usual theory, the negative sign of the constant of proportionality –8 πG which appears in the field equations R ik – ½ g ik R = –8 πGT ik is chosen arbitrarily. In the present theory there is no such ambiguity; the sign must be minus. Further, the magnitude of G follows from a determination of the mean density of matter, thereby enabling the cosmologist to know how hard he will hit the ground if he is unfortunate enough to fall over a cliff. The second point of principle is that the equation R ik = 0 for an empty world in Einstein theory becomes meaningless; there is no such thing as an ‘empty’ world; in the present theory emptiness demands no world at all. Nor can there be a world containing a single particle, the least number of particles is two.

A comparison between Rosen and Einstein theory of gravitation

1983 ◽  
Vol 54 (1-2) ◽  
pp. 97-99
Author(s):  
G. Callegari ◽  
L. Baroni
Keyword(s):  
Einstein Theory ◽  
Theory Of Gravitation

scholarly journals Centrifugal (centripetal) and Coriolis' velocities and accelerations in $$ (\bar L_n ,g) $$ -spaces

Open Physics ◽  
2003 ◽  
Vol 1 (4) ◽  
Author(s):  
Sawa Manoff
Keyword(s):  
Relative Velocity ◽  
Space Time ◽  
Gravitational Acceleration ◽  
Einstein Theory ◽  
Centripetal Acceleration ◽  
Affine Connections ◽  
Relative Acceleration ◽  
Kinematic Characteristics ◽  
Gravitational Theories ◽  
Theory Of Gravitation

AbstractThe notions of centrifugal (centripetal) and Coriolis' velocities and accelerations are introduced and considered in spaces with affine connections and metrics [ $$ (\bar L_n ,g) $$ -spaces] as velocities and accelerations of flows of mass elements (particles) moving in space-time. It is shown that these types of velocities and accelerations are generated by the relative motions between the mass elements. They are closely related to the kinematic characteristics of the relative velocity and relative acceleration. The centrifugal (centripetal) velocity is found to be in connection with the Hubble law. The centrifugal (centripetal) acceleration could be interpreted as gravitational acceleration as has been done in the Einstein theory of gravitation. This fact could be used as a basis for workingout new gravitational theories in spaces with affine connections and metrics.

scholarly journals Universality of the Einstein theory of gravitation

2016 ◽  
Vol 13 (08) ◽  
pp. 1640008 ◽  
Author(s):  
Jerzy Kijowski
Keyword(s):  
General Relativity ◽  
Variational Problems ◽  
Relativity Theory ◽  
General Relativity Theory ◽  
Einstein Theory ◽  
Metric Tensor ◽  
New Approach ◽  
Theory Of Gravitation ◽  
Tensor Formula ◽  
Matter Fields

We show that generalizations of general relativity theory, which consist in replacing the Hilbert Lagrangian [Formula: see text] by a generic scalar density [Formula: see text] depending upon the metric [Formula: see text] and the curvature tensor [Formula: see text], are equivalent to the conventional Einstein theory for a (possibly) different metric tensor [Formula: see text] and (possibly) a different set of matter fields. The simple proof of this theorem relies on a new approach to variational problems containing metric and connection.

Atomic and gravitational metrics in cosmology

1981 ◽  
Vol 374 (1759) ◽  
pp. 447-459 ◽  
Keyword(s):  
Relativistic Cosmology ◽  
De Sitter ◽  
Einstein Theory ◽  
Large Numbers ◽  
The Standard Model ◽  
Self Consistent ◽  
The Status ◽  
Theory Of Gravitation ◽  
S Model ◽  
Do So

Using inferences from his Large Numbers hypothesis (L. N. h.) Dirac (1979) derived a cosmological model, described by an ‘atomic’ metric, that is not in agreement with the Einstein theory of gravitation. He then showed that the same model described by a different metric appears to be the Einstein–de Sitter (E. S.) universe, and thus to agree with the Einstein theory. According to the first description, relative to electromagnetic forces, gravitation becomes weaker with advancing epoch. So long as the L. N. h. is retained, we point out how this physical feature persists no matter what metric is used. Therefore Dirac’s E. S. model is observably different from that of standard relativistic cosmology. We make this explicit by writing into the calculations a ‘Coulomb’ constant to match the gravitation constant. We show how the way we do so is internally self-consistent. In the course of the work it emerges that one of the two main inferences from the L. N. h. is automatically ensured by the E. S. model, which may call for some re-examination of the status of the hypothesis. We discuss the different cosmological redshifts predicted by Dirac’s E. S. model and by the standard model.

A Robertson–Walker Universe in the post-Einstein theory of gravitation and within a series of other theories

2012 ◽  
Vol 29 (6) ◽  
pp. 065007 ◽  
Author(s):  
V V Karbanovski ◽  
K E Beloushko ◽  
A S Tarasova ◽  
A B Makurin ◽  
M V Mironova
Keyword(s):  
Einstein Theory ◽  
Theory Of Gravitation

The Large Numbers hypothesis and the Einstein theory of gravitation

1979 ◽  
Vol 365 (1720) ◽  
pp. 19-30 ◽  
Keyword(s):  
Gravitational Theory ◽  
Conclusive Evidence ◽  
De Sitter ◽  
Dimensionless Numbers ◽  
Einstein Theory ◽  
Observable Universe ◽  
Slowing Down ◽  
Large Numbers ◽  
Theory Of Gravitation ◽  
The Universe

A study of the relations between large dimensionless numbers leads one to believe that G , expressed in atomic units, varies with the epoch. The Einstein theory requires G to be constant. One can reconcile these two requirements by supposing that the Einstein theory applies with a metric that differs from the atomic metric. The theory can be developed with conservation of mass by supposing that the continual increase in the mass of the observable universe arises from a continual slowing down of the velocity of recession of the galaxies. One is led to a model of the Universe that was first proposed jointly by Einstein & de Sitter (the E.S. model). The observations of the microwave radiation fit in with this model. The static Schwarzchild metric has to be modified to fit in with the E.S. model for large r . The modification is worked out, and also the motion of planets with the new metric. It is found that there is a difference between ephemeris time and atomic time, and also that there should be an inward spiralling of the planets, referred to atomic units, superposed on the motion given by ordinary gravitational theory. These are effects that can be checked by observation, but there is no conclusive evidence up to the present.

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