Further consistency tests of the stability of fundamental couplings

TL;DR

This paper updates previous tests on the stability of fundamental physical constants using recent astrophysical data, finding persistent and sometimes increased inconsistencies at high redshifts, emphasizing the need for further observational clarification.

Contribution

It provides an updated analysis of the consistency of measurements of fundamental constants, highlighting ongoing discrepancies and the importance of future high-precision observations.

Findings

Inconsistencies at about two-sigma level persist in measurements.

Discrepancies are more pronounced for high-redshift data (z>1).

Future facilities like ALMA and ESPRESSO can help clarify these issues.

Abstract

In a recent publication [Ferreira {\it et al.}, Phys. Rev. D89 (2014) 083011] we tested the consistency of current astrophysical tests of the stability of the fine-structure constant $\alpha$ and the proton-to-electron mass ratio $\mu=m_p/m_e$ (mostly obtained in the optical/ultraviolet) with combined measurements of $\alpha$, $\mu$ and the proton gyromagnetic ratio $g_p$ (mostly in the radio band). Given the significant observational progress made in the past year, we now revisit and update this analysis. We find that apparent inconsistencies, at about the two-sigma level, persist and are in some cases enhanced, especially for matter era measurements (corresponding to redshifts $z>1$). Although hidden systematics may be the more plausible explanation, we briefly highlight the importance of clarifying this issue, which is within the reach of state-of-the art observational facilities such as ALMA and ESPRESSO.