The study of space-time variations of dimensionless physical constants is a necessary approach to search for mysterious phenomena beyond the Standard Model (SM) and General Relativity (GR) motivated by Grand Unification Theories (GUTs). Potentially, the variations of these constants at any location and region of the universe could be tested by using white dwarf spectra with high gravitational fields. Based on the white dwarf star spectra of G191-B2B, our study yields an estimate for the possible cosmological deviations of the proton-to-electron mass ratio, $\mathrm{\Delta }\mu /\mu =(-0.360\pm 0.864)\times {10}^{-8}$ with a gravitational redshift $z=\mathrm{\Delta }\varphi \approx 5\times {10}^{-5}$. This limit serves as an essential tool for examining the framework of the GUTs.

研究无量纲物理常数的时空变化是寻找超越大统一理论（GUT）激发的标准模型（SM）和广义相对论（GR）之外的神秘现象的必要方法。潜在地，可以通过使用具有高引力场的白矮光谱来测试这些常数在宇宙任何位置和区域的变化。基于G191-B2B的白矮星光谱，我们的研究得出了质子与电子质量比可能的宇宙学偏差的估计，$\mathrm{\Delta }\mu /\mu =（-0.360\pm 0.864）\times {10}^{-8}$ 引力红移 $ž=\mathrm{\Delta }\varphi \approx 5\times {10}^{-5}$。此限制是检查GUT框架的重要工具。