scholarly journals Astrometric Solar-System Anomalies and Evolutionary Physical Constants

2019 ◽  
Author(s):  
Rajendra P. Gupta
Keyword(s):  
Solar System ◽  
Gravitational Constant ◽  
Hubble Constant ◽  
Secular Change ◽  
Distance Modulus ◽  
Astronomical Unit ◽  
Speed Of Light ◽  
New Approach ◽  
Orbit Eccentricity ◽  
Secular Increase

We have shown that three astrometric solar-system anomalies can be explained satisfactorily by using evolutionary gravitational constant G and speed of light c in the Einstein’s field equation. These are: a) the Pioneer acceleration anomaly; b) the anomalous secular increase of Moon-orbit eccentricity; and c) the anomalous secular change in the astronomical unit AU. The gravitational constant G and the speed of light c both increase as dG/dt = 5.4GH0 and dc/dt = 1.8cH0 with H0 as the Hubble constant. We also show that the Planck’s constant ħ increases as dħ/dt = 1.8ħH0.  Additionally, the new approach fits the supernovae Ia redshift vs distance modulus data as well as the standard ΛCDM model with just one adjustable parameter H0.

scholarly journals Varying Physical Constants, Astrometric Anomalies, Redshift and Hubble Units

Galaxies ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 55 ◽  
Author(s):  
Rajendra P. Gupta
Keyword(s):  
Hubble Constant ◽  
Astronomical Unit ◽  
Lunar Laser Ranging ◽  
Current Time ◽  
Physical Constants ◽  
Lunar Laser ◽  
Walker Metric ◽  
The One ◽  
Two Parameters ◽  
Secular Increase

We have developed a cosmological model by allowing the speed of light c, gravitational constant G and cosmological constant Λ in the Einstein filed equation to vary in time, and solved them for Robertson-Walker metric. Assuming the universe is flat and matter dominant at present, we obtain a simple model that can fit the supernovae 1a data with a single parameter almost as well as the standard ΛCDM model with two parameters, and which has the predictive capability superior to the latter. The model, together with the null results for the variation of G from the analysis of lunar laser ranging data determines that at the current time G and c both increase as dG/dt = 5.4GH0 and dc/dt = 1.8cH0 with H0 as the Hubble constant, and Λ decreases as dΛ/dt = −1.2ΛH0. This variation of G and c is all what is needed to account for the Pioneer anomaly, the anomalous secular increase of the moon eccentricity, and the anomalous secular increase of the astronomical unit. We also show that the Planck’s constant ħ increases as dħ/dt = 1.8ħH0 and the ratio D of any Hubble unit to the corresponding Planck unit increases as dD/dt = 1.5DH0. We have shown that it is essential to consider the variation of all the physical constants that may be involved directly or indirectly in a measurement rather than only the one whose variation is of interest.

scholarly journals A Priori “Imprinting” of General Relativity Itself on Some Tests of It?

2010 ◽  
Vol 2010 ◽  
pp. 1-5
Author(s):  
Lorenzo Iorio
Keyword(s):  
General Relativity ◽  
Gravitational Field ◽  
Time Delay ◽  
Solar System ◽  
Gravitational Constant ◽  
A Priori ◽  
Astronomical Unit ◽  
Space Curvature ◽  
Order Of Magnitude ◽  
Delay Tests

We investigate the effect of possible a priori “imprinting” effects of general relativity itself on satellite/spacecraft-based tests of it. We deal with some performed or proposed time-delay ranging experiments in the sun's gravitational field. It turns out that the “imprint” of general relativity on the Astronomical Unit and the solar gravitational constant , not solved for in the so far performed spacecraft-based time-delay tests, induces an a priori bias of the order of in typical solar system ranging experiments aimed to measure the space curvature PPN parameter . It is too small by one order of magnitude to be of concern for the performed Cassini experiment, but it would affect future planned or proposed tests aiming to reach a accuracy in determining .

scholarly journals Gravitational anomalies in the solar system?

2015 ◽  
Vol 24 (06) ◽  
pp. 1530015 ◽  
Author(s):  
Lorenzo Iorio
Keyword(s):  
Nineteenth Century ◽  
Solar System ◽  
Mass Parameter ◽  
Early Years ◽  
Current Status ◽  
Astronomical Unit ◽  
Theory Of Relativity ◽  
Theoretical Predictions ◽  
Secular Increase ◽  
Gravitational Anomalies

Mindful of the anomalous perihelion precession of Mercury discovered by Le Verrier in the second half of the nineteenth century and its successful explanation by Einstein with his General Theory of Relativity in the early years of the twentieth century, discrepancies among observed effects in our Solar system and their theoretical predictions on the basis of the currently accepted laws of gravitation applied to known matter-energy distributions have the potential of paving the way for remarkable advances in fundamental physics. This is particularly important now more than ever, given that most of the universe seems to be made of unknown substances dubbed Dark Matter and Dark Energy. Should this not be directly the case, Solar system's anomalies could anyhow lead to advancements in either cumulative science, as shown to us by the discovery of Neptune in the first half of the nineteenth century, and technology itself. Moreover, investigations in one of such directions can serendipitously enrich the other one as well. The current status of some alleged gravitational anomalies in the Solar system is critically reviewed. They are: (a) Possible anomalous advances of planetary perihelia. (b) Unexplained orbital residuals of a recently discovered moon of Uranus (Mab). (c) The lingering unexplained secular increase of the eccentricity of the orbit of the Moon. (d) The so-called Faint Young Sun Paradox. (e) The secular decrease of the mass parameter of the Sun. (f) The Flyby Anomaly. (g) The Pioneer Anomaly. (h) The anomalous secular increase of the astronomical unit.

scholarly journals The Flatness Problem and the Variable Physical Constants

Galaxies ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 77
Author(s):  
Rajendra P. Gupta
Keyword(s):  
Hubble Constant ◽  
Physical Constant ◽  
Big Bang ◽  
Scale Factor ◽  
Radius Of Curvature ◽  
Distance Modulus ◽  
Speed Of Light ◽  
Curvature Term ◽  
The Universe ◽  
Flatness Problem

We have used the varying physical constant approach to resolve the flatness problem in cosmology. Friedmann equations are modified to include the variability of speed of light, gravitational constant, cosmological constant, and the curvature constant. The continuity equation obtained with such modifications includes the scale factor-dependent cosmological term as well as the curvature term, along with the standard energy-momentum term. The result is that as the scale factor tends to zero (i.e., as the Big Bang is approached), the universe becomes strongly curved rather than flatter and flatter in the standard cosmology. We have used the supernovae 1a redshift versus distance modulus data to determine the curvature variation parameter of the new model, which yields a better fit to the data than the standard ΛCDM model. The universe is found to be an open type with a radius of curvature R c = 1.64   ( 1 + z ) − 3.3 c 0 / H 0 , where z is the redshift, c 0 is the current speed of light, and H 0 is the Hubble constant.

scholarly journals Determining Evolution of Cosmological Constant, Gravitational Constant and Speed of Light Using Nonadiabatic Cosmological Model and LLR Findings

Galaxies ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 67
Author(s):  
Gupta
Keyword(s):  
Dark Energy ◽  
Cosmological Constant ◽  
Gravitational Constant ◽  
Friedmann Equation ◽  
Distance Modulus ◽  
Significant Finding ◽  
Speed Of Light ◽  
Lunar Laser Ranging ◽  
Data Set ◽  
Λcdm Model

We have shown that the Hubble constant H0 embodies the information about the evolutionary nature of the cosmological constant Λ, gravitational constant G, and the speed of light c. We have derived expressions for the time evolution of G/c2 (≡K) and dark energy density εΛ related to Λ by explicitly incorporating the nonadiabatic nature of the universe in the Friedmann equation. We have found (dK/dt)/K = 1.8H0 and, for redshift z, εΛ,z/εΛ,0 = 0.4+0.61+z-1.52. Since the two expressions are related, we believe that the time variation of K (and therefore that of G and c) is manifested as dark energy in cosmological models. When we include the null finding of the lunar laser ranging (LLR) for (dG/dt)/G and relax the constraint that c is constant in LLR measurements, we get (dG/dt)/G = 5.4H0 and (dc/dt)/c = 1.8H0. Further, when we adapt the standard ΛCDM model for the z dependency of εΛ rather than it being a constant, we obtain surprisingly good results fitting the SNe Ia redshift z vs distance modulus µ data. An even more significant finding is that the new ΛCDM model, when parameterized with low redshift data set (z < 0.5), yields a significantly better fit to the data sets at high redshifts (z > 0.5) than the standard ΛCDM model. Thus, the new model may be considered robust and reliable enough for predicting distances of radiation emitting extragalactic redshift sources for which luminosity distance measurement may be difficult, unreliable, or no longer possible.

scholarly journals Varying Physical Constants, Astrometric Anomalies, Redshift and Hubble Units

2019 ◽  
Author(s):  
Rajendra P. Gupta
Keyword(s):  
Hubble Constant ◽  
Astronomical Unit ◽  
Lunar Laser Ranging ◽  
Current Time ◽  
Physical Constants ◽  
Lunar Laser ◽  
Walker Metric ◽  
The One ◽  
Two Parameters ◽  
Secular Increase

We have developed a cosmological model by allowing the speed of light c, gravitational constant G and cosmological constant Λ in the Einstein filed equation to vary in time, and solved them for Robertson-Walker metric. Assuming the universe is flat and matter dominant at present, we obtain a simple model that can fit the supernovae 1a data with a single parameter almost as well as the standard ΛCDM model with two parameters, and has the predictive capability superior to the latter. The model, together with the null results for the variation of G from the analysis of lunar laser ranging data determines that at the current time G and c both increase as dG/dt = 5.4GH0 and dc/dt = 1.8cH0 with H0 as the Hubble constant, and Λ decreases as dΛ/dt = -1.2ΛH0. This variation of G and c is all what is needed to account for the Pioneer anomaly, the anomalous secular increase of the Moon eccentricity, and the anomalous secular increase of the astronomical unit. We also show that the Planck’s constant ħ increases as dħ/dt = 1.8ħH0 and the ratio D of any Hubble unit to the corresponding Planck units increases as dD/dt = 1.5DH0. We have shown that it is essential to consider the variation of all the physical constants that may be involved directly or indirectly in a measurement rather than only the one whose variation is being considered.

scholarly journals Astrometric solar-system anomalies

2009 ◽  
Vol 5 (S261) ◽  
pp. 189-197 ◽  
Author(s):  
John D. Anderson ◽  
Michael Martin Nieto
Keyword(s):  
Solar System ◽  
Thermal Emission ◽  
New Physics ◽  
Secular Change ◽  
Orbital Energy ◽  
Astronomical Unit ◽  
The Sun ◽  
Sigma Level ◽  
The Earth ◽  
Theory Of Gravitation

AbstractThere are at least four unexplained anomalies connected with astrometric data. Perhaps the most disturbing is the fact that when a spacecraft on a flyby trajectory approaches the Earth within 2000 km or less, it often experiences a change in total orbital energy per unit mass. Next, a secular change in the astronomical unit AU is definitely a concern. It is reportedly increasing by about 15 cm yr−1. The other two anomalies are perhaps less disturbing because of known sources of nongravitational acceleration. The first is an apparent slowing of the two Pioneer spacecraft as they exit the solar system in opposite directions. Some astronomers and physicists, including us, are convinced this effect is of concern, but many others are convinced it is produced by a nearly identical thermal emission from both spacecraft, in a direction away from the Sun, thereby producing acceleration toward the Sun. The fourth anomaly is a measured increase in the eccentricity of the Moon's orbit. Here again, an increase is expected from tidal friction in both the Earth and Moon. However, there is a reported unexplained increase that is significant at the three-sigma level. It is prudent to suspect that all four anomalies have mundane explanations, or that one or more anomalies are a result of systematic error. Yet they might eventually be explained by new physics. For example, a slightly modified theory of gravitation is not ruled out, perhaps analogous to Einstein's 1916 explanation for the excess precession of Mercury's perihelion.

scholarly journals The Flatness Problem and the Varying Physical Constants

2019 ◽  
Author(s):  
Rajendra P. Gupta
Keyword(s):  
Hubble Constant ◽  
Physical Constant ◽  
Big Bang ◽  
Scale Factor ◽  
Radius Of Curvature ◽  
Distance Modulus ◽  
Speed Of Light ◽  
Curvature Term ◽  
The Universe ◽  
Flatness Problem

We have used the varying physical constant approach to resolve the flatness problem in cosmology. Friedmann equations are modified to include variability of speed of light, gravitational constant, cosmological constant and the curvature constant. The continuity equation obtained with such modifications includes scale factor dependent cosmological term as well as the curvature term along with the standard energy-momentum term. The result is that as the scale factor tends to zero (i.e. as the big-bang is approached) the universe becomes strongly curved rather than flatter and flatter in the standard cosmology. We have used the supernovae 1a redshift versus distance modulus data to determine the curvature variation parameter of the new model, which yields a better fit to the data than the standard &Lambda;CDM model. The universe is found to be open type with radius of curvature Rc = 1.64 (1+z)-3.3 c0/H0, where z is the redshift, c0 is the current speed of light and H0 is the Hubble constant.

scholarly journals "IMPRINTING" IN GENERAL RELATIVITY TESTS?

2011 ◽  
Vol 20 (10) ◽  
pp. 1945-1948
Author(s):  
LORENZO IORIO
Keyword(s):  
General Relativity ◽  
Gravitational Field ◽  
Time Delay ◽  
Solar System ◽  
Gravitational Constant ◽  
A Priori ◽  
Astronomical Unit ◽  
Delay Test ◽  
Space Curvature ◽  
Order Of Magnitude

We investigate possible a priori "imprinting" of general relativity itself on spaceraft-based tests of it. We deal with some performed or proposed time-delay ranging experiments in the Sun's gravitational field. The "imprint" of general relativity on the Astronomical Unit and the solar gravitational constant GM⊙, not solved for in the spacecraft-based time-delay test performed so far, may induce an a priori bias of the order of 10-6 in typical solar system ranging experiments aimed to measuring the space curvature PPN parameter γ. It is too small by one order of magnitude to be of concern for the performed Cassini experiment, but it would affect future planned or proposed tests aiming to reach a 10-7–10-9 accuracy in determining γ.

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