Tests of strong-field gravity and gravitational radiation damping in binary-pulsar systems
2
Citation
1
Reference
10
Related Paper
Citation Trend
Abstract:
This talk reviews the constraints imposed by binary-pulsar data on gravity theories, and notably on "scalar-tensor" theories which are the most natural alternatives to general relativity. Because neutron stars have a strong gravitational binding energy, binary-pulsar tests are qualitatively different from solar-system experiments: They have the capability of probing models which are indistinguishable from general relativity in weak gravitational field conditions. Besides the two most precise binary-pulsar experiments, in the systems B1913+16 and B1534+12, we also present the results of the various "null" tests of general relativity provided by several neutron star-white dwarf binaries, notably those of gravitational radiation damping. [The main interest of this very short paper is its figure, which also takes into account the "strong equivalence principle" tests.]Keywords:
Equivalence principle (geometric)
Speed of gravity
Gravity Probe A
Abstract The article contains sections titled: Introduction General Relativity and Relativistic Gravity Gravitation Theory: An Overview Relativistic Gravity in Physics Where Relativistic Gravity Is Important Fundamental Ideas and New Concepts of General Relativity The Incorporation of Newtonian Gravity Basic Ingredients of General Relativity General Relativity: Gravity as Geometry Sources of Gravity: How Matter Creates the Geometry Other Theories of Gravity A Cosmological Term in E instein's Equations Some Consequences of Einstein's Field Equations Momentum and Stress Also Make Gravity Gravitomagnetism Gravitational Collapse Black‐Hole Theory Black Holes in the Eighteenth Century Black Holes in General Relativity Singularities Inside the Hole Black Holes Have No Hair Black‐Hole Thermodynamics Wormholes Gravitational Waves The Necessity of Gravitational Waves The Interaction of Gravitational Waves with Matter Wave Emission: The Quadrupole Formula Applications of General Relativity Relativistic Stars (Pulsars) and Gravitational Collapse Black Holes in X ‐Ray Binaries and in Galactic Centers Gravitational Lensing Solar System and Stellar Orbits Cosmology, Inflation, and the Origins of the Universe Tests of Gravitational Theories and Their Technological Demands Tests of the E instein Equivalence Principle Tests of Special Relativity The E ötvös Experiment, the Weak Equivalence Principle, and the Fifth Force Gravitational Redshift Solar‐System Tests of General Relativity The Deflection and Retardation of Light M ercury's Perihelion Advance Test of the Strong Equivalence Principle The Binary Pulsar: An Astronomical Relativity Laboratory Future Work in Experimental Gravitation Search for Gravitomagnetic Effects Tests of the E instein Equivalence Principle Further Fifth‐Force Searches Gravitational‐wave Detection: A Technological Frontier Likely Sources of Detectable Waves Supernovae Coalescing Binaries Pulsars Ordinary Binaries Cosmological Background Unexpected Sources Detectors Bar‐Type Detectors Laser‐Interferometric Detectors Space‐Based Detectors
Equivalence principle (geometric)
Black hole (networking)
Gravitational time dilation
Speed of gravity
Gravity Probe A
Cite
Citations (2)
Gravitational field is a kind of vector field,and the description of general relativity to gravitational force problem is very effective.This paper deals with the equivalence principle and the principle of general covariance in general relativity,discusses Einstein’s gravitational field equations,researches on the principle of relativity,time dilation,contraction of length in gravitational field.
Gravitational time dilation
Equivalence principle (geometric)
General Covariance
Gravity Probe A
Speed of gravity
Cite
Citations (0)
A proper discussion of the various philosophical views of the nature of time and gravitational field and the different issues related to time as such would take us far beyond the scope of this article. For our purposes, time and gravitational field are related somehow. In any case, especially due to Einstein’s relativity theory, there is a very close relationship between time the gravitational field and vice versa. The aim of this publication is to work out the interior logic between gravitational field and time. As we will see, the gravitational field is equivalent to time and vice versa, both are equivalent or identical.
Gravity Probe A
Gravitational time dilation
Speed of gravity
Equivalence principle (geometric)
Gravitational constant
Versa
Cite
Citations (0)
Equivalence principle (geometric)
Gravity Probe A
Speed of gravity
Cite
Citations (0)
This history of experimentation relevant to general relativity covers the time post-1928. Classes of investigation are the weak equivalence principle (equivalence of inertial and gravitational mass and gravitational redshift), orbital precession of a body in gravitational fields (the relativistic perihelion advance of the planets, the relativistic periastron advance of binary pulsars, geodetic precession and Lense-Thirring effect), light propagation in gravitational fields (gravitational optical light deflection, gravitational radio deflection due to the Sun, gravitational lensing, time dilation and atomic clocks) and strong gravity implications (Nordtved effect and potential gravitational waves). The results of experiments are analysed to conclude to what extent they support general relativity. A number of questions are then answered: (a) how much evidence exists to support general relativity, (b) is it a reasonable way of thinking and (c) what is the niche it may occupy? Key words: general relativity, equivalence principle, orbital precession, gravitational fields.
Gravity Probe A
Equivalence principle (geometric)
Gravitational time dilation
Speed of gravity
Cite
Citations (4)
A simple general relativity theory for objects moving in gravitational fields is developed based on studying the behavior of an atom in a gravitational field. The theory is applied to calculate the satellite time dilation, light deflection by the sun, and Mercury's precession with an error of less than 1%. The approach to the new theory introduced here is radically different from the geometric approach used by Einstein's general relativity. The theory is field based where the potential energy of a system of masses can be easily calculated and the force can be found as the gradient of the potential field in analogy to the Newtonian mechanics. The resulting field equations become the traditional Newton's equations when week gravitational effects are present. The theory complies with all the known experimental results such as the gravitational time dilation and faster light speeds higher in the gravitational field. The special relativity theory of an object moving without experiencing gravitational fields can be derived directly from the gravitational field equations introduced here. The theory introduced here has crucial differences to Einstein's general relativity theory. For example, the gravitational field cannot accelerate an object to higher than the speed of light and the event horizon of a black hole (where light cannot escape) has to be of zero radius, essentially meaning that light can escape any object unless the object has infinite density. Another primary consequence of this study is that the principle of equivalence of gravitational and inertial mass has only limited validity and a new definition of gravitational mass is given here.
Gravitational time dilation
Gravity Probe A
Speed of gravity
Equivalence principle (geometric)
Linearized gravity
Gravitational binding energy
Cite
Citations (0)
Equivalence principle (geometric)
Speed of gravity
Gravitational time dilation
Gravity Probe A
Cite
Citations (5)
This paper has been withdrawn by the author after further work showed the proposed theoretical approach cannot fit planetary perihelion precession data. As presented, the theory doesn't fit gravitational light deflection by the sun either, but a straightforward theoretical change does remedy that; however a proper fit to planetary perihelion precession data is not thus obtained. The author's stated philosophical objections to the Einstein equation can be dealt with in a markedly different way -- a new paper entitled "Unique Einstein Gravity from Feynman's Lorentz Condition" has been submitted. Einstein's equivalence principle implies that the acceleration of a particle in a "specified" gravitational field is independent of its mass. While this is certainly true to great accuracy for bodies we observe in the Earth's gravitational field, a hypothetical body of mass comparable to the Earth's would perceptibly cause the Earth to fall toward it, which would feed back into the strength as a function of time of the Earth's gravitational field affecting that body. In short, Einstein's equivalence principle isn't exact, but is an approximation that ignores recoil of the "specified" gravitational field, which sheds light on why general relativity has no clearly delineated native embodiment of conserved four-momentum. Einstein's 1905 relativity of course doesn't have the inexactitudes he unwittingly built into GR, so it is natural to explore a Lorentz-covariant gravitational theory patterned directly on electromagnetism, wherein a system's zero-divergence overall stress-energy, including all gravitational feedback contributions, is the source of its gravitational tensor potential. Remarkably, that alone completely determines Lorentz-covariant gravity's interaction with any conservative system of locally interacting classical fields; no additional "principles" of any kind are required. The highly intricate equation for the gravitational interaction contribution to such a system's Lagrangian density is only amenable to solution by successively refined approximation, however.
Gravity Probe A
Speed of gravity
Equivalence principle (geometric)
Linearized gravity
Cite
Citations (0)
Time and space are important for relativity study in physics. In matter space exists a gravitational field, owning to which time is varied, space is bent, and light trace is changed.It discusses theory of relativity featuring the characteristics of time and space, the principles of equivalence and general covariance in general relativity, gravitational field equations, the principle of relativity, time dilation, contraction of length, and gravitational waves in gravitational field.
Gravitational time dilation
Gravity Probe A
Equivalence principle (geometric)
General Covariance
Speed of gravity
Cite
Citations (0)
The international gravitational community should hold in high esteem the efforts of experimentalists during the period from the middle of the 60's until the beginning of the 90's. The list of remarkable achievements during this period should include the following. (i) The high precision measurements of the deflection and of the delay of EM radiation in gravitational fields as well as the red-blue frequency shift. These experiments confirmed the validity of Einstein's theory of general relativity at the relative error level of N in the non-wavezone for the weak gravitational field (in other words for 9/c2 <( 1). (ii) The detection of nonlinear gravitational interaction of masses (also predicted by general relativity) which was observed in the change of the shape of EM pulses from a pulsar delayed in the gravitational field of a companion neutron star. (iii)The indirect confirmation of the existence of gravitational radiation by the precise measurement of the motion of two close neutron stars. In this experiment the prediction of general relativity was confirmed to the level of N lo-'. (iv)Several attempts to find violation of the principle of equivalence or the existence of a fifth force have given null results to high levels of precision. Summing up these experimental results one can conclude that during this thii year interval general relativity has obtained a solid experimental basis for the case of a weak gravitational field. Readers may find reviews of these results in the article by Will [I], in [2,3] and in the articles quoted in these publications. These experimental results must be regarded as a direct product of the newly developed scientific technologies which include high-precision space measurements, stable highfrequency sources and several others. It is reasonable to expect that until the end of this century, space and terrestrial experiments [4,5] aimed at observing the gravitomagoetical interaction will be realized. Parallel to the above listed research, during almost the same interval of time, the experimentalists have created a technological foundation for gravitational wave astronomy. Starting with the pioneering works of Weber several versions of the cryogenical bar-antennae and the so-called laser interferometric antennae on free masses have been tested. The progress in this area may be described by two numerical results: at the start of the 70's the sensitivity of the bar antennae was h N (3 + 1) x (in the dimensionless units of the amplitude of the perturbation of metric), while by the beginning of the 90's the sensitivity of bar-antennae and of the prototypes of full-scale laser antennae was better than h N 1 x It is important to note that the development of this technique was associated with the theoretical analysis of the sensitivity of the antennae, in particular, ind of the
Equivalence principle (geometric)
Speed of gravity
Gravity Probe A
Cite
Citations (6)