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arXiv · astro-ph/9204002

Gravitational Lensing and the Variability of G

Lawrence Krauss·Martin White
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Abstract

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 $Ω_0$ from lensing observations.

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Lawrence Krauss, Martin White. 1992-04-26. Gravitational Lensing and the Variability of G. https://doi.org/10.1086/171792

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