On variations of G in the geometric scalar theory of gravity

Abstract

We analyze the possible variability of the effective Newtonian gravitational constant $$G_{\mathrm{N}}$$GN in space and time in the framework of the geometric scalar theory of gravity suggested by Novello et al. (JCAP 06:014, 2013). Spatial variations of $$G_{\mathrm{N}}$$GN in the Solar system are shown to have orders of magnitude detectable by modern instruments. As to variations of $$G_{\mathrm{N}}$$GN with cosmological time, it is shown (at least for the particular formulation of the theory discussed in the original paper and the corresponding cosmological models) that these variations are more rapid than is allowed by observations.

A search for a secular variation of the gravitational constant using strong gravitational fields

“…Recently derived a set of new bound constraints < 1.6 × 10 −12 yr −1 referring to the comparison data of six telescopes while the most stringent constrained = ( − 0.6 ± 4.2) × 10 −12 yr −1 at 2σ using -mode spectra [46][47][48][49][50][51][52][53][54][55]. However, all the current studies would only estimate the -varying at a level of 10 −12 yr −1 [56][57][58][59][60].…”

Fundamental physical constants: results in search for and description of variations

“…For example, the well-known scalar-tensor theories have the Einstein limit as their parameter ω, characterizing the scalar field coupling with curvature, tends to infinity; according to the totality of measurements in the Solar system, this parameter should currently be not less than 40,000 [38]. The recently formulated scalar-metric theory of gravity [39], which gained some success, has turned out to be incompatible with observations precisely because of a too rapid change in the effective gravitational constant predicted by this theory [40].…”