scholarly journals RELATIVISTIC EFFECTS IN EXTRASOLAR PLANETARY SYSTEMS

2006 ◽  
Vol 15 (12) ◽  
pp. 2133-2140 ◽  
Author(s):  
FRED C. ADAMS ◽  
GREGORY LAUGHLIN
Keyword(s):  
General Relativity ◽  
Solar System ◽  
Planetary Systems ◽  
Relativistic Effects ◽  
Interaction Theory ◽  
Orbital Elements ◽  
Secular Resonance ◽  
The Future ◽  
General Relativistic ◽  
Temporal Coverage

This paper considers general relativistic (GR) effects in currently observed extrasolar planetary systems. Although GR corrections are small, they can compete with secular interactions in these systems and thereby play an important role. Specifically, some of the observed multiple planet systems are close to secular resonance, where the dynamics is extremely sensitive to GR corrections, and these systems can be used as laboratories to test general relativity. For the three-planet solar system Upsilon Andromedae, secular interaction theory implies an 80% probability of finding the system with its observed orbital elements if GR is correct, compared with only a 2% probability in the absence of GR. In the future, tighter constraints can be obtained with increased temporal coverage.

On claims that general relativity differs from Newtonian physics for self-gravitating dusts in the low velocity, weak field limit

2015 ◽  
Vol 24 (08) ◽  
pp. 1550065 ◽  
Author(s):  
David R. Rowland
Keyword(s):  
General Relativity ◽  
Solar System ◽  
Relativistic Effects ◽  
Weak Field ◽  
Newtonian Gravity ◽  
Galactic Rotation ◽  
Low Velocity ◽  
Rotation Curves ◽  
Newtonian Physics ◽  
General Relativistic

Galaxy rotation curves are generally analyzed theoretically using Newtonian physics; however, two groups of authors have claimed that for self-gravitating dusts, general relativity (GR) makes significantly different predictions to Newtonian physics, even in the weak field, low velocity limit. One group has even gone so far as to claim that nonlinear general relativistic effects can explain flat galactic rotation curves without the need for cold dark matter. These claims seem to contradict the well-known fact that the weak field, low velocity, low pressure correspondence limit of GR is Newtonian gravity, as evidenced by solar system tests. Both groups of authors claim that their conclusions do not contradict this fact, with Cooperstock and Tieu arguing that the reason is that for the solar system, we have test particles orbiting a central gravitating body, whereas for a galaxy, each star is both an orbiting body and a contributor to the net gravitational field, and this supposedly makes a difference due to nonlinear general relativistic effects. Given the significance of these claims for analyses of the flat galactic rotation curve problem, this article compares the predictions of GR and Newtonian gravity for three cases of self-gravitating dusts for which the exact general relativistic solutions are known. These investigations reveal that GR and Newtonian gravity are in excellent agreement in the appropriate limits, thus supporting the conventional use of Newtonian physics to analyze galactic rotation curves. These analyses also reveal some sources of error in the referred to works.

Beyond the Schwarzschild Metric

2018 ◽  
Author(s):  
David M. Wittman
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Gravitational Waves ◽  
Test Particle ◽  
Direct Detection ◽  
Relativistic Effects ◽  
Big Bang ◽  
Clusters Of Galaxies ◽  
General Relativistic ◽  
The Universe

General relativity explains much more than the spacetime around static spherical masses.We briefly assess general relativity in the larger context of physical theories, then explore various general relativistic effects that have no Newtonian analog. First, source massmotion gives rise to gravitomagnetic effects on test particles.These effects also depend on the velocity of the test particle, which has substantial implications for orbits around black holes to be further explored in Chapter 20. Second, any changes in the sourcemass ripple outward as gravitational waves, and we tell the century‐long story from the prediction of gravitational waves to their first direct detection in 2015. Third, the deflection of light by galaxies and clusters of galaxies allows us to map the amount and distribution of mass in the universe in astonishing detail. Finally, general relativity enables modeling the universe as a whole, and we explore the resulting Big Bang cosmology.

scholarly journals On the 2PN Periastron Precession of the Double Pulsar PSR J0737–3039A/B

Universe ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 443
Author(s):  
Lorenzo Iorio
Keyword(s):  
General Relativity ◽  
Present Author ◽  
Moment Of Inertia ◽  
The Other ◽  
Orbital Elements ◽  
Binary Pulsars ◽  
Orbital Phase ◽  
Order Of Magnitude ◽  
General Relativistic ◽  
The Moment

One of the post-Keplerian (PK) parameters determined in timing analyses of several binary pulsars is the fractional periastron advance per orbit kPK. Along with other PK parameters, it is used in testing general relativity once it is translated into the periastron precession ω˙PK. It was recently remarked that the periastron ω of PSR J0737–3039A/B may be used to measure/constrain the moment of inertia of A through the extraction of the general relativistic Lense–Thirring precession ω˙LT,A≃−0.00060∘yr−1 from the experimentally determined periastron rate ω˙obs provided that the other post-Newtonian (PN) contributions to ω˙exp can be accurately modeled. Among them, the 2PN seems to be of the same order of magnitude of ω˙LT,A. An analytical expression of the total 2PN periastron precession ω˙2PN in terms of the osculating Keplerian orbital elements, valid not only for binary pulsars, is provided, thereby elucidating the subtleties implied in correctly calculating it from k1PN+k2PN and correcting some past errors by the present author. The formula for ω˙2PN is demonstrated to be equivalent to that obtainable from k1PN+k2PN by Damour and Schäfer expressed in the Damour–Deruelle (DD) parameterization. ω˙2PN actually depends on the initial orbital phase, hidden in the DD picture, so that −0.00080∘yr−1≤ω˙2PN≤−0.00045∘yr−1. A recently released prediction of ω˙2PN for PSR J0737–3039A/B is discussed.

scholarly journals RELXILL_NK: A Black Hole Relativistic Reflection Model for Testing General Relativity

Proceedings ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 7 ◽  
Author(s):  
Askar B. Abdikamalov ◽  
Dimitry Ayzenberg ◽  
Cosimo Bambi  ◽  
Sourabh Nampalliwar
Keyword(s):  
General Relativity ◽  
Black Hole ◽  
Relativistic Effects ◽  
Asymptotically Flat ◽  
X Ray ◽  
Black Hole Accretion ◽  
Reflection Model ◽  
Black Hole Spacetime ◽  
General Relativistic ◽  
Hole Accretion

In this paper, we briefly present RELXILL_NK, the first and currently only readily available model of the relativistic reflection spectrum of black hole accretion disks that includes non-Kerr solutions for the black hole spacetime, thus allowing for tests of the Kerr hypothesis and general relativity (GR). RELXILL_NK makes use of a general relativistic ray-tracing code to calculate the relativistic effects of any well-behaved, stationary, axisymmetric, and asymptotically flat black hole spacetime, while the disk physics is handled through the non-relativistic X-ray reflection code XILLVER. A number of different flavors are available within RELXILL_NK; we summarize and compare these flavors using the Johannsen metric for the black hole spacetime.

scholarly journals On the foundations of general relativistic celestial mechanics

2017 ◽  
Vol 32 (26) ◽  
pp. 1730022 ◽  
Author(s):  
Emmanuele Battista ◽  
Giampiero Esposito ◽  
Simone Dell’Agnello
Keyword(s):  
General Relativity ◽  
Solar System ◽  
Celestial Mechanics ◽  
Body Problem ◽  
Equations Of Motion ◽  
Modern Science ◽  
N Body Problem ◽  
General Relativistic ◽  
New Perspective ◽  
Three Body

Towards the end of nineteenth century, Celestial Mechanics provided the most powerful tools to test Newtonian gravity in the solar system and also led to the discovery of chaos in modern science. Nowadays, in light of general relativity, Celestial Mechanics leads to a new perspective on the motion of satellites and planets. The reader is here introduced to the modern formulation of the problem of motion, following what the leaders in the field have been teaching since the nineties, in particular, the use of a global chart for the overall dynamics of N bodies and N local charts describing the internal dynamics of each body. The next logical step studies in detail how to split the N-body problem into two sub-problems concerning the internal and external dynamics, how to achieve the effacement properties that would allow a decoupling of the two sub-problems, how to define external-potential-effacing coordinates and how to generalize the Newtonian multipole and tidal moments. The review paper ends with an assessment of the nonlocal equations of motion obtained within such a framework, a description of the modifications induced by general relativity on the theoretical analysis of the Newtonian three-body problem, and a mention of the potentialities of the analysis of solar-system metric data carried out with the Planetary Ephemeris Program.

scholarly journals Prospects for observations of relativistic effects in the solar system

1986 ◽  
Vol 114 ◽  
pp. 383-391
Author(s):  
R. D. Reasenberg ◽  
I. I. Shapiro
Keyword(s):  
General Relativity ◽  
Solar System ◽  
Space Shuttle ◽  
Space Station ◽  
Relativistic Effects ◽  
Dramatic Improvement ◽  
Optical Interferometer ◽  
Theory Of Gravitation ◽  
Theories Of Gravitation ◽  
Solar Gravity

The solar system is the traditional laboratory for testing theories of gravitation. The results of all tests are consistent with the predictions of general relativity. The differences between these predictions and those of Newton's theory of gravitation have been confirmed with uncertainties as small as one part in a thousand. To enhance significantly the accuracy of such tests, one must investigate novel techniques. In this paper we concentrate on an experiment that promises a dramatic improvement in a classical test of general relativity – the deflection of light by solar gravity. The goal is to measure the post-post-Newtonian contribution of nearly 11 microarcseconds to this deflection. The technique we propose is based on use of an astrometric optical interferometer, POINTS, which could be operated from the bay of the Space Shuttle, mounted on the proposed Space Station, or supported by an independent spacecraft. POINTS should be able to measure the separation of stars about 90° apart with an uncertainty of only a few microarcseconds.

scholarly journals Detecting the general relativistic orbital precession of the exoplanet HD 80606b

2019 ◽  
Vol 628 ◽  
pp. A80 ◽  
Author(s):  
Luc Blanchet ◽  
Guillaume Hébrard ◽  
François Larrouturou
Keyword(s):  
Orbital Motion ◽  
Relativistic Effects ◽  
Time Difference ◽  
High Eccentricity ◽  
Space Telescope ◽  
Transit Times ◽  
The Future ◽  
General Relativistic ◽  
Orbital Precession

We investigate the relativistic effects in the orbital motion of the exoplanet HD 80606b with a high eccentricity of e ≃ 0.93. We propose a method to detect these effects (notably the orbital precession) based on measuring the successive eclipse and transit times of the exoplanet. In the case of HD 80606b, we find that in ten years (after approximately 33 periods) the instants of transits and eclipses are delayed with respect to the Newtonian prediction by about three minutes due to relativistic effects. These effects can be detected by comparing at different epochs the time difference between a transit and the preceding eclipse, and should be measurable by comparing events already observed on HD 80606 in 2010 with the Spitzer satellite together with those to be observed in the future with the James Webb Space Telescope.

scholarly journals Radar time delays in the dynamic theory of gravity

2004 ◽  
pp. 49-54
Author(s):  
I.I. Haranas
Keyword(s):  
General Relativity ◽  
Solar System ◽  
Time Delays ◽  
Dynamic Theory ◽  
Dimensional Space ◽  
Gravity Potential ◽  
Spherically Symmetric ◽  
Time Element ◽  
General Relativistic ◽  
Theory Of Gravity

There is a new theory gravity called the dynamic theory, which is derived from thermodynamic principles in a five dimensional space, radar signals traveling times and delays are calculated for the major planets in the solar system, and compared to those of general relativity. This is done by using the usual four dimensional spherically symmetric space-time element of classical general relativistic gravity which has now been slightly modified by a negative inverse radial exponential term due to the dynamic theory of gravity potential.

scholarly journals General Relativistic Theory of Rotating Neutron Stars – A Review

1971 ◽  
Vol 46 ◽  
pp. 334-340
Author(s):  
Jeffrey M. Cohen
Keyword(s):  
General Relativity ◽  
Neutron Stars ◽  
Relativistic Theory ◽  
White Dwarfs ◽  
Relativistic Effects ◽  
Red Shift ◽  
Light Bending ◽  
Perihelion Advance ◽  
General Relativistic

Except in cosmology, astrophysicists are used to thinking of general relativistic effects as small (e.g., light bending, perihelion advance, red shift) and have generally left such problems to general relativists. However, the discovery of pulsars (Hewish et al., 1968) may have changed this. Not only is general relativity necessary to treat rotating neutron stars, but relativity was also partly responsible for the elimination of pulsating white dwarfs as pulsar models.

scholarly journals Relativistic effects in Earth based and cosmic long baseline interferometry

1986 ◽  
Vol 114 ◽  
pp. 255-268
Author(s):  
W. H. Cannon ◽  
D. Lisewski ◽  
A. M. Finkelstein ◽  
V. Ya Kreinovich
Keyword(s):  
General Relativity ◽  
Future Development ◽  
Very Long Baseline Interferometry ◽  
Relativistic Effects ◽  
Wide Band ◽  
Optical Observations ◽  
Geodetic Measurement ◽  
Global Networks ◽  
Long Baseline ◽  
The Future

With present day technology the technique which provides the greatest precision in astrometric and geodetic measurement is Very Long Baseline Interferometry (VLBI) (Robertson, 1975; Dravskykh, 1981; Gubanov, 1983). The precision of present day astrometrical measurements by VLBI exceeds those of the best modern optical observations by an order and a half of magnitude and is capable of further improvement by the future development of phase stable, wide band, global networks and by the future deployment of VLBI antennas in space. Such precision of observation places the technique of VLBI well within the regime of special and general relativity. The present paper presents an analysis of relativistic effects on VLBI measurements with an accuracy of 0.0001 arc seconds.

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