scholarly journals MODIFIED JORDAN–BRANS–DICKE THEORY WITH SCALAR CURRENT AND THE EDDINGTON–ROBERTSON γ-PARAMETER

2012 ◽  
Vol 21 (12) ◽  
pp. 1250084 ◽  
Author(s):  
J. W. MOFFAT ◽  
V. T. TOTH
Keyword(s):  
Scalar Field ◽  
Solar System ◽  
Gravitational Constant ◽  
Weak Equivalence Principle ◽  
A Value ◽  
Specific Choice ◽  
Modified Gravity Theory ◽  
General Relativistic ◽  
Theory Of Gravitation ◽  
Scalar Current

The Jordan–Brans–Dicke theory of gravitation, which promotes the gravitational constant to a dynamical scalar field, predicts a value for the Eddington–Robertson post-Newtonian parameter γ that is significantly different from the general relativistic value of unity. This contradicts precision solar system measurements that tightly constrain γ around 1. We consider a modification of the theory, in which the scalar field is sourced explicitly by matter. We find that this leads to a modified expression for the γ-parameter. In particular, a specific choice of the scalar current yields γ = 1, just as in general relativity, while the weak equivalence principle is also satisfied. This result has important implications for theories that mimic Jordan–Brans–Dicke theory in the post-Newtonian limit in the solar system, including our scalar–tensor–vector gravity (STVG) modified gravity theory (MOG).

A NEW THEORY OF GRAVITATION WITH PARITY-VIOLATING PROPAGATING TORSION

1994 ◽  
Vol 09 (22) ◽  
pp. 3959-3968 ◽  
Author(s):  
RAMANAND JHA
Keyword(s):  
Scalar Field ◽  
Solar System ◽  
Space Time ◽  
Experimental Results ◽  
Interesting Consequence ◽  
General Space ◽  
Theory Of Gravitation

A new theory of gravitation has been proposed in a more general space–time than Riemannian. It is a generalization of the ECSK and Brans–Dicke (BD) theory of gravitation. It is found that, in contrast to the standard the ECSK theory, a parity-violating propagating torsion is generated by the BD scalar field. The interesting consequence of the theory is that it can successfully predict solar system experimental results to desired accuracy.

scholarly journals Simulation of general relativistic corrections in long term numerical integrations of planetary orbits

1986 ◽  
Vol 114 ◽  
pp. 105-111
Author(s):  
Anna M. Nobili ◽  
Ian W. Roxburgh
Keyword(s):  
General Relativity ◽  
Solar System ◽  
Computer Time ◽  
Substantial Improvement ◽  
Numerical Integrations ◽  
Planetary Orbits ◽  
General Relativistic ◽  
Theory Of Gravitation ◽  
The Stability

Long term numerical integrations of planetary orbits designed to study the stability of the Solar System over timescales comparable to its age have become very promising thanks to the availability of very powerful computers and to a substantial improvement in our methods of investigating the stability of hierarchical dynamical systems. The stability of such numerical integrations relies on the ability to control all possible sources of error. Among the errors caused by the inadequacy of the physical model are those due to the fact that Newton's theory of gravitation is used instead of general relativity. We show that the secular advance of perihelia predicted by general relativity can be simulated exactly by a 1/r2 perturbing potential with almost negligible additional cost in computer time.

scholarly journals THE SCALAR ETHER-THEORY OF GRAVITATION AND ITS FIRST TEST IN CELESTIAL MECHANICS

2002 ◽  
Vol 17 (29) ◽  
pp. 4203-4208 ◽  
Author(s):  
MAYEUL ARMINJON
Keyword(s):  
General Relativity ◽  
Scalar Field ◽  
Solar System ◽  
Celestial Mechanics ◽  
Equations Of Motion ◽  
Alternative Interpretation ◽  
Crucial Point ◽  
Ether Theory ◽  
Theory Of Gravitation ◽  
Basic Equations

The motivations for investigating a theory of gravitation based on a concept of "ether" are discussed — a crucial point is the existence of an alternative interpretation of special relativity, named the Lorentz-Poincaré ether theory. The basic equations of one such theory of gravity, based on just one scalar field, are presented. To check this theory in celestial mechanics, an "asymptotic" scheme of post-Newtonian (PN) approximation is summarized and its difference with the standard PN scheme is emphasized. The derivation of PN equations of motion for the mass centers, based on the asymptotic scheme, is outlined. They are implemented for the major bodies of the solar system and the prediction for Mercury is compared with an ephemeris based on general relativity.

Higgs-like field from extended theory of gravitation

2014 ◽  
Vol 11 (02) ◽  
pp. 1460001
Author(s):  
L. Fatibene ◽  
M. Ferraris ◽  
G. Magnano ◽  
M. Palese ◽  
M. Capone ◽  
...  
Keyword(s):  
Scalar Field ◽  
Extended Theory ◽  
Theory Of Gravitation ◽  
Conformal Scalar Field

We shall consider possible potentials emerging in (purely metric) f(R)-theories for the conformal scalar field. We shall discuss possible approaches to determine models with specific potentials and show that some potentials qualitatively similar to the typical Higgs potentials are allowed.

scholarly journals CAN GENERAL RELATIVISTIC DESCRIPTION OF GRAVITATION BE CONSIDERED COMPLETE?

1998 ◽  
Vol 13 (17) ◽  
pp. 1393-1400 ◽  
Author(s):  
D. V. AHLUWALIA
Keyword(s):  
Solar System ◽  
Gravitational Potential ◽  
Invariance Properties ◽  
Planetary Orbits ◽  
Galactic Cluster ◽  
General Relativistic ◽  
Relativistic Description ◽  
Flavor Oscillation ◽  
Weak Fields ◽  
Great Attractor

The local galactic cluster, the Great attractor, embeds us in a dimensionless gravitational potential of about -3×10-5. In the solar system, this potential is constant to about 1 part in 1011. Consequently, planetary orbits, which are determined by the gradient in the gravitational potential, remain unaffected. However, this is not so for the recently introduced flavor-oscillation clocks where the new redshift-inducing phases depend on the gravitational potential itself. On these grounds, and by studying the invariance properties of the gravitational phenomenon in the weak fields, we argue that there exists an element of incompleteness in the general relativistic description of gravitation. An incompleteness-establishing inequality is derived and an experiment is outlined to test the thesis presented.

scholarly journals Reflections on a measurement of the gravitational constant using a beam balance and 13 tons of mercury

2014 ◽  
Vol 372 (2026) ◽  
pp. 20140027 ◽  
Author(s):  
S. Schlamminger ◽  
R. E. Pixley ◽  
F. Nolting ◽  
J. Schurr ◽  
U. Straumann
Keyword(s):  
Gravitational Constant ◽  
Beam Balance ◽  
A Value ◽  
University Of Zurich ◽  
The University ◽  
Experimental Effort

In 2006, a final result of a measurement of the gravi- tational constant G performed by researchers at the University of Zürich, Switzerland, was published. A value of G =6.674252(122)×10 −11  m 3  kg −1  s −2 was obtained after an experimental effort that lasted over one decade. Here, we briefly summarize the measurement and discuss the strengths and weaknesses of this approach.

scholarly journals CONSTRAINING THE PREFERRED-FRAME α1, α2 PARAMETERS FROM SOLAR SYSTEM PLANETARY PRECESSIONS

2014 ◽  
Vol 23 (01) ◽  
pp. 1450006 ◽  
Author(s):  
L. IORIO
Keyword(s):  
Binary System ◽  
Solar System ◽  
Relative Motion ◽  
A Priori ◽  
The Other ◽  
Preferred Frame ◽  
General Relativistic ◽  
Ppn Parameters ◽  
Invariable Plane ◽  
Analytical Expressions

Analytical expressions for the orbital precessions affecting the relative motion of the components of a local binary system induced by Lorentz-violating Preferred Frame Effects (PFE) are explicitly computed in terms of the Parametrized Post-Newtonian (PPN) parameters α1, α2. Preliminary constraints on α1, α2 are inferred from the latest determinations of the observationally admitted ranges [Formula: see text] for any anomalous Solar System planetary perihelion precessions. Other bounds existing in the literature are critically reviewed, with particular emphasis on the constraint [Formula: see text] based on an interpretation of the current close alignment of the Sun's equator with the invariable plane of the Solar System in terms of the action of a α2-induced torque throughout the entire Solar System's existence. Taken individually, the supplementary precessions [Formula: see text] of Earth and Mercury, recently determined with the INPOP10a ephemerides without modeling PFE, yield α1 = (0.8±4) × 10-6 and α2 = (4±6) × 10-6, respectively. A linear combination of the supplementary perihelion precessions of all the inner planets of the Solar System, able to remove the a priori bias of unmodeled/mismodeled standard effects such as the general relativistic Lense–Thirring precessions and the classical rates due to the Sun's oblateness J2, allows to infer α1 = (-1 ± 6) × 10-6, α2 = (-0.9 ± 3.5) × 10-5. Such figures are obtained by assuming that the ranges of values for the anomalous perihelion precessions are entirely due to the unmodeled effects of α1 and α2. Our bounds should be improved in the near-mid future with the MESSENGER and, especially, BepiColombo spacecrafts. Nonetheless, it is worthwhile noticing that our constraints are close to those predicted for BepiColombo in two independent studies. In further dedicated planetary analyses, PFE may be explicitly modeled to estimate α1, α2 simultaneously with the other PPN parameters as well.

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