Gravitational lensing and the variability of G

Lawrence M. Krauss, Martin White

Research output: Contribution to journalArticlepeer-review

19 Scopus citations


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 probe the variation of G over cosmological time. We estimate constraints on 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 G today, but unfortunately extracting this information is not independent of the effort to fix other cosmological parameters such as Ho and Ωo from lensing observations.

Original languageEnglish (US)
Pages (from-to)357-361
Number of pages5
JournalAstrophysical Journal
Issue number2
StatePublished - 1992
Externally publishedYes


  • Cosmology: theory
  • Gravitation
  • Gravitational lensing

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'Gravitational lensing and the variability of G'. Together they form a unique fingerprint.

Cite this