Probing Gravitational Theories with Eccentric Eclipsing Detached Binary Stars

In this paper, we compare the effects of different theories of gravitation on the apsidal motion of eccentric eclipsing detached binary stars. The comparison is performed by using the formalism of the post-Newtonian parametrization to calculate the theoretical advance at periastron and compare it to the observed one, after having considered the effects of the structure and rotation of the involved stars. A variance analysis on the results of this comparison shows that no signicant difference can be found due to the effect of the different theories under test with respect to the standard general relativity (GR). It will be possible to observe differences, as we would expect, by checking the observed period variation on a much larger lapse of time.

Download Full-text

Experimental consequences of the nonsymmetric gravitational theory including the apsidal motion of binaries

Canadian Journal of Physics ◽

10.1139/p86-031 ◽

1986 ◽

Vol 64 (2) ◽

pp. 178-184 ◽

Cited By ~ 5

Author(s):

J. W. Moffat

Keyword(s):

General Relativity ◽

Binary System ◽

Gravitational Theory ◽

Apsidal Motion ◽

Gravitational Theories

The experimental consequences of the nonsymmetric gravitational theory (NGT) are reviewed. The observed periastron motion of the binary system DI Her is compared with the predictions of general relativity and NGT. The systems NY Cep, DH Cep, and ι Ori are proposed as potentially significant candidates to test the gravitational theories.

Download Full-text

Testing Gravitational Theories in the Field of the Earth with the SaToR-G Experiment

Universe ◽

10.3390/universe7060192 ◽

2021 ◽

Vol 7 (6) ◽

pp. 192

Author(s):

David Lucchesi ◽

Luciano Anselmo ◽

Massimo Bassan ◽

Marco Lucente ◽

Carmelo Magnafico ◽

...

Keyword(s):

General Relativity ◽

State Of The Art ◽

Current Knowledge ◽

Slow Motion ◽

Weak Field ◽

New Physics ◽

The State ◽

The Earth ◽

Gravitational Theories ◽

Theories Of Gravitation

A new satellite-based experiment in the field of gravitation, SaToR-G, is presented. It aims to compare the predictions of different theories of gravitation in the limit of weak-field and slow-motion. The ultimate goal of SaToR-G is searching for possible “new physics” beyond General Relativity, which represent the state-of-the-art of our current knowledge of gravitational physics. A key role in the above perspective is the theoretical and experimental framework that confines our work. To this end, we will exploit as much as possible the classical framework suggested by R.H. Dicke over fifty years ago.

Download Full-text

Astronomical tests of relativity: beyond parameterized post-Newtonian formalism (PPN), to testing fundamental principles

Proceedings of the International Astronomical Union ◽

10.1017/s1743921309990159 ◽

2009 ◽

Vol 5 (S261) ◽

pp. 56-61 ◽

Cited By ~ 1

Author(s):

Vladik Kreinovich

Keyword(s):

General Relativity ◽

Quantum Physics ◽

Final Theory ◽

Gravitational Theories ◽

Cosmological Observations ◽

Partial Analysis ◽

Theory Of Gravitation ◽

Improved Accuracy ◽

Fundamental Physical ◽

Relativistic Gravitation

AbstractBy the early 1970s, the improved accuracy of astrometric and time measurements enabled researchers not only to experimentally compare relativistic gravity with the Newtonian predictions, but also to compare different relativistic gravitational theories (e.g., the Brans-Dicke Scalar-Tensor Theory of Gravitation). For this comparison, Kip Thorne and others developed the Parameterized Post-Newtonian Formalism (PPN), and derived the dependence of different astronomically observable effects on the values of the corresponding parameters.Since then, all the observations have confirmed General Relativity. In other words, the question of which relativistic gravitation theory is in the best accordance with the experiments has been largely settled. This does not mean that General Relativity is the final theory of gravitation: it needs to be reconciled with quantum physics (into quantum gravity), it may also need to be reconciled with numerous surprising cosmological observations, etc. It is, therefore, reasonable to prepare an extended version of the PPN formalism, that will enable us to test possible quantum-related modifications of General Relativity.In particular, we need to include the possibility of violating fundamental principles that underlie the PPN formalism but that may be violated in quantum physics, such as scale-invariance, T-invariance, P-invariance, energy conservation, spatial isotropy violations, etc. In this paper, we present the first attempt to design the corresponding extended PPN formalism, with the (partial) analysis of the relation between the corresponding fundamental physical principles.

Download Full-text

The theory of spherically symmetric thin shells in conformal gravity

International Journal of Modern Physics D ◽

10.1142/s0218271818410122 ◽

2018 ◽

Vol 27 (06) ◽

pp. 1841012 ◽

Cited By ~ 2

Author(s):

Victor Berezin ◽

Vyacheslav Dokuchaev ◽

Yury Eroshenko

Keyword(s):

General Relativity ◽

Weyl Tensor ◽

Delta Function ◽

Einstein Gravity ◽

Riemann Tensor ◽

Momentum Tensor ◽

Thin Shells ◽

Spherically Symmetric ◽

Gravitational Fields ◽

Gravitational Theories

The spherically symmetric thin shells are the nearest generalizations of the point-like particles. Moreover, they serve as the simple sources of the gravitational fields both in General Relativity and much more complex quadratic gravity theories. We are interested in the special and physically important case when all the quadratic in curvature tensor (Riemann tensor) and its contractions (Ricci tensor and scalar curvature) terms are present in the form of the square of Weyl tensor. By definition, the energy–momentum tensor of the thin shell is proportional to Diracs delta-function. We constructed the theory of the spherically symmetric thin shells for three types of gravitational theories with the shell: (1) General Relativity; (2) Pure conformal (Weyl) gravity where the gravitational part of the total Lagrangian is just the square of the Weyl tensor; (3) Weyl–Einstein gravity. The results are compared with these in General Relativity (Israel equations). We considered in detail the shells immersed in the vacuum. Some peculiar properties of such shells are found. In particular, for the traceless ([Formula: see text] massless) shell, it is shown that their dynamics cannot be derived from the matching conditions and, thus, is completely arbitrary. On the contrary, in the case of the Weyl–Einstein gravity, the trajectory of the same type of shell is completely restored even without knowledge of the outside solution.

Download Full-text

HOLLOWGRAPHY DRIVEN HOLOGRAPHY: BLACK HOLE WITH VANISHING VOLUME INTERIOR

International Journal of Modern Physics D ◽

10.1142/s0218271810018426 ◽

2010 ◽

Vol 19 (14) ◽

pp. 2345-2351 ◽

Cited By ~ 5

Author(s):

AHARON DAVIDSON ◽

ILYA GURWICH

Keyword(s):

Phase Transition ◽

General Relativity ◽

Black Hole ◽

Degrees Of Freedom ◽

Schwarzschild Solution ◽

Entropy Formula ◽

Gravitational Theories ◽

Hollow Interior ◽

Spatial Volume ◽

Self Similar

Hawking–Bekenstein entropy formula seems to tell us that no quantum degrees of freedom can reside in the interior of a black hole. We suggest that this is a consequence of the fact that the volume of any interior sphere of finite surface area simply vanishes. Obviously, this is not the case in general relativity. However, we show that such a phenomenon does occur in various gravitational theories which admit a spontaneously induced general relativity. In such theories, due to a phase transition (one-parameter family degenerates) which takes place precisely at the would-have-been horizon, the recovered exterior Schwarzschild solution connects, by means of a self-similar transition profile, with a novel "hollow" interior exhibiting a vanishing spatial volume and a locally varying Newton constant. This constitutes the so-called "hollowgraphy" driven holography.

Download Full-text

Gravitational Theories Beyond General Relativity

10.1007/978-3-030-21197-4 ◽

2019 ◽

Author(s):

Iberê Kuntz

Keyword(s):

General Relativity ◽

Gravitational Theories

Download Full-text

Berichte: Mach's Principle - A Critical Review

Zeitschrift für Naturforschung A ◽

10.1515/zna-1973-3-431 ◽

1973 ◽

Vol 28 (3-4) ◽

pp. 529-537 ◽

Cited By ~ 2

Author(s):

Michael Reinhardt

Keyword(s):

General Relativity ◽

Selection Rule ◽

Inertial Mass ◽

Physical Principle ◽

Mach's Principle ◽

Mach’S Principle ◽

Field Equations ◽

Basic Physical Principle ◽

Theories Of Gravitation

AbstractAfter a short historical introduction it is discussed how far Mach's principle is incorporated into general relativity. The possible role of Mach's principle as a selection rule for the solutions of Einstein's field equations is summarized. Then follows a discussion of Math's principle in theories of gravitation other than Einstein's, mainly the Brans-Dicke theory. Finally the experiments on the isotropy of inertial mass and their consequence for Mach's principle are described. The conclusion is that Mach's principle, though an extremely stimulating thought, has at present little claim to be a basic physical principle.

Download Full-text