AI 中文总结
该研究利用HST/STIS获取的白矮星G191-B2B的Ni V吸收线光谱，高精度测试强引力场中牛顿常数G的时间变化，结果支持G恒定并为其强场长期变化提供严格约束，表明白矮星是灵敏探针。
AI 中文摘要
牛顿引力常数G的恒定性是广义相对论的基本预测，也是超越广义相对论的引力理论的关键假设。我们利用哈勃空间望远镜成像光谱仪（HST/STIS）获取的白矮星G191-B2B中Ni V吸收线的高分辨率紫外光谱，对强引力场中G的可能时间变化进行了高精度测试。通过将测量的线心与实验室波长比较并分离引力红移贡献，我们在约10^4的强引力势φ下得到dG/G = (-0.014 ± 0.016) × 10^-15 yr^-1，对应吸收红移z_abs约8.47×10^-5。该结果与G恒定一致，对强场区域G的长期变化施加了严格约束。我们的测量表明白矮星作为探测引力耦合时间变化的灵敏探针具有潜力。
英文摘要
The constancy of Newton's gravitational constant G is a fundamental prediction underlying general relativity and a critical assumption in theories of gravity beyond it. We report a high-precision test of a possible temporal variation of G in a strong gravitational field, using high-resolution ultraviolet spectra of Ni V absorption lines in the white dwarf G191-B2B obtained with the Hubble Space Telescope Imaging Spectrograph (HST/STIS). By comparing the measured line centroids with laboratory wavelengths and isolating the gravitational-redshift contribution, we obtain dG/G = (-0.014 +/- 0.016) x 10^-15 yr^-1 at a strong-field potential phi approximately 10^4, corresponding to an absorption redshift z_abs approximately 8.47 x 10^-5. The result is consistent with a constant G and places a stringent constraint on its secular variation in the strong-field regime. Our measurement demonstrates the potential of white-dwarf stars as a sensitive probe of temporal variations in the gravitational coupling.
