Consistency tests of the stability of fundamental couplings and unification scenarios

TL;DR

This paper assesses the consistency of astrophysical measurements of fundamental constants, revealing potential systematic issues and discussing implications for unification theories, emphasizing the need for more precise future observations.

Contribution

It compares different astrophysical measurements of fundamental constants and highlights possible inconsistencies, informing future experimental and theoretical work in fundamental physics.

Findings

Potential inconsistencies in measurements suggest hidden systematics.

Future observations with advanced telescopes are crucial.

Current data impact unification scenario constraints.

Abstract

We test the consistency of several independent astrophysical measurements of fundamental dimensionless constants. In particular, we compare direct measurements of the fine-structure constant $\alpha$ and the proton-to-electron mass ratio $\mu=m_p/m_e$ (mostly in the optical/ultraviolet) with combined measurements of $\alpha$, $\mu$ and the proton gyromagnetic ratio $g_p$ (mostly in the radio band). We point out some apparent inconsistencies, which suggest that hidden systematics may be affecting some of the measurements. These findings demonstrate the importance of future more precise measurements with ALMA, ESPRESSO and ELT-HIRES. We also highlight some of the implications of the currently available measurements for fundamental physics, specifically for unification scenarios.