Constraints on the spatial and temporal variations of the gravitational constant from quasar spectra

Abstract

The possible variations of fundamental physical constants present a critical examination of grand unification theories (GUTs). The most useful way to investigate these variations could be based on observations that directly test them with a deep-look back in time in the universe. Using combinations of high-resolution spectra of quasars and Ritz wavelengths in the laboratory, we found an upper limit on a possible cosmological deviation of the gravitational ̇ ⁄ = (0.918 ± 2.830) × 10 yr over cosmic timescales.. This result may be considered as a new tool for checking the physical phenomena of the GUTs.