Gravitational lensing statistics and constraints on the cosmological constant revisited

Yu Chung N Cheng, Lawrence Krauss

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

We re-analyze constraints on the cosmological constant that can be obtained by examining the statistics of strong gravitational lensing of distant quasars by intervening galaxies, focusing on uncertainties in galaxy models (including velocity dispersion, luminosity functions, core radii and magnification bias effects) and on the parameters of the galaxy distribution and luminosity functions. In the process we derive new results on magnification biasing for galaxy lenses with nonzero core radii, and on how to infer the proper velocity dispersions appropriate for use in lensing statistics. We argue that the existing data do not disfavor a large cosmological constant. In fact, for a set of reasonable parameter choices, using the results of five optical quasar lensing surveys we find that a maximum likelihood analysis favors a value of Ω0 in the range ≃ 0.25 - 0.55 in a flat universe. An open cosmology is not favored by the same statistical analysis. Systematic uncertainties are likely to be dominant, however, as these results are sensitive to uncertainties in our understanding of galaxy luminosity functions, and dark matter velocity dispersions, as well as the choice of lensing survey, and to a lesser extent the existence of core radii. Further observational work will be required before it is possible to definitively distinguish between cosmological models on the basis of gravitational lensing statistics.

Original languageEnglish (US)
Pages (from-to)697-723
Number of pages27
JournalInternational Journal of Modern Physics A
Volume15
Issue number5
StatePublished - Feb 20 2000
Externally publishedYes

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Gravitational Lensing
Galaxies
Cosmological Constant
statistics
galaxies
Statistics
Quasars
Radius
luminosity
magnification
Uncertainty
quasars
radii
Cosmological Models
Dark Matter
Cosmology
statistical analysis
cosmology
Statistical Analysis
Maximum Likelihood

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Mathematical Physics
  • Nuclear and High Energy Physics

Cite this

Gravitational lensing statistics and constraints on the cosmological constant revisited. / Cheng, Yu Chung N; Krauss, Lawrence.

In: International Journal of Modern Physics A, Vol. 15, No. 5, 20.02.2000, p. 697-723.

Research output: Contribution to journalArticle

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