scholarly journals A precise extragalactic test of General Relativity

Science ◽  
2018 ◽  
Vol 360 (6395) ◽  
pp. 1342-1346 ◽  
Author(s):  
Thomas E. Collett ◽  
Lindsay J. Oldham ◽  
Russell J. Smith ◽  
Matthew W. Auger ◽  
Kyle B. Westfall ◽  
...  

Einstein’s theory of gravity, General Relativity, has been precisely tested on Solar System scales, but the long-range nature of gravity is still poorly constrained. The nearby strong gravitational lens ESO 325-G004 provides a laboratory to probe the weak-field regime of gravity and measure the spatial curvature generated per unit mass, γ. By reconstructing the observed light profile of the lensed arcs and the observed spatially resolved stellar kinematics with a single self-consistent model, we conclude that γ = 0.97 ± 0.09 at 68% confidence. Our result is consistent with the prediction of 1 from General Relativity and provides a strong extragalactic constraint on the weak-field metric of gravity.

2015 ◽  
Vol 24 (08) ◽  
pp. 1550065 ◽  
Author(s):  
David R. Rowland

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.


1997 ◽  
Vol 55 (1) ◽  
pp. 395-402 ◽  
Author(s):  
Valeriy V. Ginzburg ◽  
Leo Radzihovsky ◽  
Noel A. Clark

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
J. M. Maciel ◽  
M. A. Amato ◽  
M. -C. Firpo

2008 ◽  
Vol 17 (03n04) ◽  
pp. 475-488 ◽  
Author(s):  
H. BALASIN ◽  
D. GRUMILLER

Exact stationary axially symmetric solutions to the four-dimensional Einstein equations with corotating pressureless perfect fluid sources are studied. A particular solution with an approximately flat rotation curve is discussed in some detail. We find that simple Newtonian arguments overestimate the amount of matter needed to explain such curves by more than 30%. The crucial insight gained by this model is that the Newtonian approximation breaks down in an extended rotating region, even though it is valid locally everywhere. No conflict with solar system tests arises.


2010 ◽  
Vol 25 (29) ◽  
pp. 5399-5408 ◽  
Author(s):  
L. IORIO ◽  
M. L. RUGGIERO

We focus on Hořava–Lifshitz (HL) theory of gravity, and, in particular, on the Kehagias and Sfetsos's solution that is the analog of Schwarzschild black hole of General Relativity. In the weak-field and slow-motion approximation, we analytically work out the secular precession of the longitude of the pericentre ϖ of a test particle induced by this solution. Its analytical form is different from that of the general relativistic Einstein's pericentre precession. Then, we compare it to the latest determinations of the corrections [Formula: see text] to the standard Newtonian/Einsteinian planetary perihelion precessions recently estimated by E. V. Pitjeva with the EPM2008 ephemerides. It turns out that the planets of the solar system, taken singularly one at a time, allow one to put lower bounds on the adimensional HL parameter ψ0 of the order of 10-12(Mercury)-10-24 (Pluto). They are not able to account for the Pioneer anomalous acceleration for r > 20 AU.


2002 ◽  
Vol 5 ◽  
pp. 65-65
Author(s):  
S. Liberatore ◽  
J.-P.J. Lafon ◽  
N. Berruyer

Physics ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 160-172
Author(s):  
G. Hathaway ◽  
L. L. Williams

We report test results searching for an effect of electrostatic charge on weight. For conducting test objects of mass of order 1 kg, we found no effect on weight, for potentials ranging from 10 V to 200 kV, corresponding to charge states ranging from 10−9 to over 10−5 coulombs, and for both polarities, to within a measurement precision of 2 g. While such a result may not be unexpected, this is the first unipolar, high-voltage, meter-scale, static test for electro-gravitic effects reported in the literature. Our investigation was motivated by the search for possible coupling to a long-range scalar field that could surround the planet, yet go otherwise undetected. The large buoyancy force predicted within the classical Kaluza theory involving a long-range scalar field is falsified by our results, and this appears to be the first such experimental test of the classical Kaluza theory in the weak field regime, where it was otherwise thought identical with known physics. A parameterization is suggested to organize the variety of electro-gravitic experiment designs.


1989 ◽  
Vol 104 (2) ◽  
pp. 49-52
Author(s):  
Suzanne L. Hawley

AbstractPhotometric and spectroscopic observations of a very large flare on AD Leo are presented. A self consistent model of a flare corona, transition region and chromosphere is developed; in particular the chromospheric temperature distributions resulting from X-ray and EUV irradiation by coronae of various temperatures are determined. The predicted line fluxes in Hγ are compared to the observed line fluxes to find the coronal temperature as a function of time during the flare. This run of temperature with time is then compared with the predictions of an independent theoretical flare model based on a dynamic scaling law (see paper by Fisher and Hawley, these proceedings).


2020 ◽  
Vol 132 (46) ◽  
pp. 20523-20527
Author(s):  
Oishi Sanyal ◽  
Samuel S. Hays ◽  
Nicholas E. León ◽  
Yoseph A. Guta ◽  
Arun K. Itta ◽  
...  

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