2025/02/20 by Renzhi Su, Su, Renzhi, Tao An +11 · 1 voice · 1 citation
Earth and Planetary Sciences · Engineering · Physics and Astronomy · #Astrophysics of Galaxies (astro-ph.GA) #Calibration and Measurement Techniques #FOS: Physical sciences #Geophysics and Gravity Measurements #astro-ph.GA
paper · pdf · doi:10.48550/arxiv.2502.14576
openalex publication_date 2025/02/20 · arxiv published 2025/02/20 · arxiv updated 2025/02/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The quantum nature of gravity remains one of the greatest mysteries of modern physics, with many unified theories predicting variations in fundamental constants across space and time. Here we present precise measurements of these variations at galactic dynamical timescales - a critical but previously unexplored regime. Using simultaneous observations of H i and OH lines in M31, we probe potential variations of fundamental constants at a lookback time of 2.5 million years. We obtained Δ(μα2gp0.64)/(μα2gp0.64) < 3.6 × 10-6, with complementary constraints on Δ(μα2)/(μα2) < 4.6 × 10-3, and Δgp/gp < 7.2 × 10-3, where α is the fine structure constant, μ is the proton-electron mass ratio, and gp is the proton g-factor. These results bridge the gap between laboratory tests and cosmological observations, providing unique insights into the coupling between local dynamics and fundamental physics. Our findings challenge theories predicting significant variations over galactic timescales, while demonstrating a powerful new probe of quantum gravity models.