The Constancy of the Constants of Nature: Updates

TL;DR

This paper reviews the latest observational and experimental bounds on whether fundamental constants of nature, such as alpha, G, and mu, have varied over time, highlighting current constraints and implications.

Contribution

It provides an updated review of the bounds on the time variation of fundamental constants based on recent observational and experimental data.

Findings

Current bounds strongly limit variation of constants over cosmological timescales

No definitive evidence for variation of alpha, G, or mu found

Constraints help refine theories of physics beyond the Standard Model

Abstract

The current observational and experimental bounds on the time variation of the constants of nature (the fine structure constant $\alpha$, the gravitational constant $G$ and the proton-electron mass ratio $\mu=m_p/m_e$) are reviewed.