Practical Limitations on Astrophysical Observations of Methanol to Investigate Variations in the Proton-to-Electron Mass Ratio

TL;DR

This paper discusses the practical challenges and limitations of using astrophysical methanol observations to detect variations in the proton-to-electron mass ratio, concluding that current methods cannot significantly improve existing constraints.

Contribution

It provides a detailed analysis of instrumental and astrophysical limitations affecting the use of methanol observations for measuring fundamental constant variations.

Findings

Current observational limitations prevent significant improvements in constraints.

Astrophysical and instrumental factors limit the sensitivity of methanol-based measurements.

Observations are unlikely to surpass existing bounds on proton-to-electron mass ratio variations.

Abstract

The possibility of using astrophysical observations of rotational transitions in the methanol molecule to measure, or constrain temporal and spatial variations in the proton-to-electron mass ratio (mu) has recently been investigated by several groups. Here we outline some of the practical considerations of making such observations, including both the instrumental and astrophysical limitations which exist at present. This leads us to conclude that such observations are unlikely to be able to improve evidence either for, or against the presence of variations in the proton-to-electron mass ratio by more than an order of magnitude beyond current limits.