标题： 引力透镜效应与G的变异性 显示英文标题

标题： Gravitational Lensing and the Variability of G

摘要： 与遥远类星体通过沿视线方向的星系引力透镜效应相关的四个可观测量：图像分裂、相对增益、时间延迟和光学深度，提供了宇宙距离处引力常数 $G$ 强度的不同度量。 原则上，这些可观测量允许我们剔除未知的透镜参数，从而直接探测 $G$ 随宇宙时间的变化。 我们估计了这种方法现在和未来可能得到的关于 $\dot{G}$ 的限制。 获得的限制可以与当今通过其他直接方法对 $\dot{G}$ 的限制竞争甚至超越，但遗憾的是，提取这一信息并非独立于从透镜观测中确定其他宇宙学参数（如 $H_0$ 和 $\Omega_0$）的努力。 显示英文摘要

摘要： The four observables associated with gravitational lensing of distant quasars by intervening galaxies: image splittings, relative amplifications, time delays, and optical depths, provide separate measures of the strength of the gravitational constant $G$ at cosmological distances. These allow one, in principle, to factor out unknown lensing parameters to directly to probe the variation of $G$ over cosmological time. We estimate constraints on $\dot{G}$ which may be derivable by this method both now and in the future. The limits one may obtain can compete or exceed other direct limits on $\dot{G}$ today, but unfortunately extracting this information, is not independent of the effort to fix other cosmological parameters such as $H_0$ and $\Omega_0$ from lensing observations.