Post-post-Newtonian deflection of light by the Sun

In classical mechanics, in the case of gravitational and electromagnetic interactions, the force on a particle is usually proportional to its acceleration: The force acts locally on the particle. However, there are situations possible-if the particle moves through a suitable medium, for example, in which the force depends also on the first-time derivative of its acceleration, the jerk, and on its second-time derivative, the snap, and possibly also on higher-time derivatives. Such forces are called nonlocal, and this work investigates such nonlocal forces, mainly those depending on the jerk. In particular, we implement jerk and acceleration in geodesics by means of the nonlocal-in-time kinetic energy approach to spacetime physics. We describe a framework that can be used to estimate the quantum nonlocal time parameter by studying the deflection of light around the Sun. Comparing our results with long baseline interferometry (VLBI) observations, we concluded that the nonlocal time parameter [Formula: see text] s.

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Testing general relativity with geodetic VLBI

Astronomy and Astrophysics ◽

10.1051/0004-6361/201833459 ◽

2018 ◽

Vol 618 ◽

pp. A8 ◽

Cited By ~ 4

Author(s):

O. Titov ◽

A. Girdiuk ◽

S. B. Lambert ◽

J. Lovell ◽

J. McCallum ◽

...

Keyword(s):

General Relativity ◽

Solar Corona ◽

Radio Sources ◽

The Sun ◽

Dual Frequency ◽

Single Session ◽

Tests Of General Relativity ◽

Geodetic Vlbi ◽

Deflection Of Light ◽

Group Delays

Context. We highlight the capabilities of geodetic VLBI technique to test general relativity in the classical astrometric style, i.e. measuring the deflection of light in the vicinity of the Sun.Aims. In previous studies, the parameterγwas estimated by global analyses of thousands of geodetic VLBI sessions. Here we estimateγfrom a single session where the Sun has approached two strong reference radio sources, 0229+131 and 0235+164, at an elongation angle of 1–3°.Methods. The AUA020 VLBI session of 1 May 2017 was designed to obtain more than 1000 group delays from the two radio sources. The solar corona effect was effectively calibrated with the dual-frequency observations even at small elongation.Results. We obtainedγwith a greater precision (0.9 × 10−4) than has been obtained through global analyses of thousands of standard geodetic sessions over decades. Current results demonstrate that the modern VLBI technology is capable of establishing new limits on observational tests of general relativity.

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Experiments on Frequency Dependence of the Deflection of Light in Yang-Mills Gravity

EPJ Web of Conferences ◽

10.1051/epjconf/201816802004 ◽

2018 ◽

Vol 168 ◽

pp. 02004

Author(s):

Yun Hao ◽

Yiyi Zhu ◽

Jong-Ping Hsu

Keyword(s):

Deflection Angle ◽

Systematic Errors ◽

Space Time ◽

The Sun ◽

Geometric Optics ◽

Metric Tensor ◽

Yang Mills ◽

Deflection Of Light ◽

Small Uncertainty ◽

The Deflection Angle

In Yang-Mills gravity based on flat space-time, the eikonal equation for a light ray is derived from the modified Maxwell’s wave equations in the geometric-optics limit. One obtains a Hamilton-Jacobi type equation, GLµv∂µΨ∂vΨ = 0 with an effective Riemannian metric tensor GLµv. According to Yang-Mills gravity, light rays (and macroscopic objects) move as if they were in an effective curved space-time with a metric tensor. The deflection angle of a light ray by the sun is about 1.53″ for experiments with optical frequencies ≈ 1014Hz. It is roughly 12% smaller than the usual value 1.75″. However, the experimental data in the past 100 years for the deflection of light by the sun in optical frequencies have uncertainties of (10-20)% due to large systematic errors. If one does not take the geometric-optics limit, one has the equation, GLµv[∂µΨ∂vΨcosΨ+ (∂µ∂vΨ)sinΨ] = 0, which suggests that the deflection angle could be frequency-dependent, according to Yang-Mills gravity. Nowadays, one has very accurate data in the radio frequencies ≈ 109Hz with uncertainties less than 0.1%. Thus, one can test this suggestion by using frequencies ≈ 1012 Hz, which could have a small uncertainty 0.1% due to the absence of systematic errors in the very long baseline interferometry.

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