Do Lensing Statistics Rule Out a Cosmological Constant?
Abstract
We present new calculations of gravitational lensing statistics in view of recent revisions in our knowledge of the luminosity function and internal velocity dispersion of E/S0 galaxies that work as effective lenses for background highredshift QSOs. We show that the theoretical prediction of the lensing statistics is much smaller than previously expected. In sharp contrast to earlier statistics supporting an Ω_{0} = 1 universe, the small lensing probability reported from the Hubble Space Telescope (HST) Snapshot Lens Survey is in best agreement with a lowdensity, flat universe with Ω_{0} ~= 0.2 and Ω_{0} + λ_{0} = 1. The age of this universe, combined with the HST measurement of a high value for the Hubble constant H_{0}, can be reconciled with the age of the oldest globular clusters in the Milky Way.
 Publication:

The Astrophysical Journal
 Pub Date:
 November 1997
 DOI:
 10.1086/304831
 Bibcode:
 1997ApJ...489..485C
 Keywords:

 Cosmology: Theory;
 Galaxies: General;
 Cosmology: Gravitational Lensing