Search for variability in Newton's constant using local gravitational acceleration measurements

Abstract

In a recent work, Dai (arXiv:2103.11157) searched for a variability in Newton's constant $G$ using the IGETS based gravitational acceleration measurements. However, this analysis, obtained from $\chi^2$ minimization, did not incorporate the errors in the gravitational acceleration measurements. We carry out a similar search with one major improvement, wherein we incorporate these aforementioned errors. To model any possible variation in the gravitational acceleration, we fit the data to four models: a constant value, two sinusoidal models, and finally, a linear model for the variation of gravitational acceleration. We find that none of the four models provides a good fit to the data, showing that there is no evidence for a periodicity or a linear temporal variation in the acceleration measurements. We then redid these analyses after accounting for an unknown intrinsic scatter. After this, we find that although a constant model is still favored over the sinusoidal models, the linear variation for $G$ is marginally preferred over a constant value, using information theory-based methods.