A test of unification towards the radio source PKS1413+135

TL;DR

This paper demonstrates how astrophysical measurements towards PKS1413+135 can constrain fundamental physical constants and unification theories, serving as a proof of concept for future more precise tests with upcoming observational facilities.

Contribution

It shows that existing measurements can individually constrain fundamental couplings and compare these constraints with local atomic clock results, highlighting potential for future tests.

Findings

Current measurements are not yet precise enough to test the spatial dipole scenario.

Measurements can constrain unification scenarios.

Comparison with atomic clock constraints is possible.

Abstract

We point out that existing astrophysical measurements of combinations of the fine-structure constant $\alpha$, the proton-to-electron mass ratio $\mu$ and the proton gyromagnetic ratio $g_p$ towards the radio source PKS1413+135 can be used to individually constrain each of these fundamental couplings. While the accuracy of the available measurements is not yet sufficient to test the spatial dipole scenario, our analysis serves as a proof of concept as new observational facilities will soon allow significantly more robust tests. Moreover, these measurements can also be used to obtain constraints on certain classes of unification scenarios, and we compare the constraints obtained for PKS1413+135 with those previously obtained from local atomic clock measurements.