Can (dG/dt)/G Bound the Local Cosmological Dynamics?

TL;DR

This paper discusses the limitations of using local measurements of gravitational constant variation to constrain the broader cosmological expansion, highlighting the disconnect between planetary-scale and cosmological-scale dynamics.

Contribution

It clarifies that local (dG/dt)/G constraints cannot be directly applied to cosmological expansion, challenging previous assumptions.

Findings

Local (dG/dt)/G limits do not directly restrict cosmological expansion

Planetary-scale measurements cannot be straightforwardly extrapolated to cosmological scales

The paper emphasizes the need for separate considerations in cosmological constraints

Abstract

It is argued that constraints on time variation of the gravitational constant (dG/dt)/G, e.g. derived from the lunar laser ranging, cannot be immediately applied to restrict the cosmological expansion at planetary scales, as it was done by Williams, Turyshev, and Boggs [PRL, 93, 261101 (2004), arXiv:gr-qc/0411113].