Breakdown of the NewtonEinstein Standard Gravity at Low Acceleration in Internal Dynamics of Wide Binary Stars
Abstract
A gravitational anomaly is found at weak gravitational acceleration g _{N} ≲ 10^{9} m s^{2} from analyses of the dynamics of wide binary stars selected from the Gaia DR3 database that have accurate distances, proper motions, and reliably inferred stellar masses. Implicit highorder multiplicities are required and the multiplicity fraction is calibrated so that binary internal motions agree statistically with Newtonian dynamics at a high enough acceleration of ≈10^{8} m s^{2}. The observed skyprojected motions and separation are deprojected to the 3D relative velocity v and separation r through a Monte Carlo method, and a statistical relation between the Newtonian acceleration g _{N} ≡ GM/r ^{2} (where M is the total mass of the binary system) and a kinematic acceleration g ≡ v ^{2}/r is compared with the corresponding relation predicted by Newtonian dynamics. The empirical acceleration relation at ≲10^{9} m s^{2} systematically deviates from the Newtonian expectation. A gravitational anomaly parameter δ _{obsnewt} between the observed acceleration at g _{N} and the Newtonian prediction is measured to be: δ _{obsnewt} = 0.034 ± 0.007 and 0.109 ± 0.013 at g _{N} ≈ 10^{8.91} and 10^{10.15} m s^{2}, from the main sample of 26,615 wide binaries within 200 pc. These two deviations in the same direction represent a 10σ significance. The deviation represents a direct evidence for the breakdown of standard gravity at weak acceleration. At g _{N} = 10^{10.15} m s^{2}, the observed to Newtonpredicted acceleration ratio is ${g}_{\mathrm{obs}}/{g}_{\mathrm{pred}}={10}^{\sqrt{2}{\delta }_{\mathrm{obs}\mathrm{newt}}}=1.43\pm 0.06$ . This systematic deviation agrees with the boost factor that the AQUAL theory predicts for kinematic accelerations in circular orbits under the Galactic external field.
 Publication:

The Astrophysical Journal
 Pub Date:
 August 2023
 DOI:
 10.3847/15384357/ace101
 arXiv:
 arXiv:2305.04613
 Bibcode:
 2023ApJ...952..128C
 Keywords:

 Binary stars;
 Gravitation;
 Modified Newtonian dynamics;
 Nonstandard theories of gravity;
 154;
 661;
 1069;
 1118;
 Astrophysics  Astrophysics of Galaxies;
 Astrophysics  Solar and Stellar Astrophysics;
 General Relativity and Quantum Cosmology;
 High Energy Physics  Theory
 EPrint:
 A revised version of the published ApJ paper (2023, 952, 128) including corrections of Figures 12, 18, 20, and Equation (4) to be published in an erratum in press: all corrections are minor and have no impact on the contents or conclusion of the paper