Decaying A cosmologies and statistical properties of gravitational lenses

Abstract

In this paper we investigate the statistical properties of gravitational lenses for models in which a cosmological term decreases with time as ∧ ∝α−m, where α is the scale factor, and m is a parameter (0 ≤m < 3). We show that for given low values of the present matter density parameter Ωm0, there is a wide range of values for m for which the lensing rate is significantly smaller than that in cosmological constant (∧) models. We also show that models with low Ωm0 and m ≿ 1 have a high likelihood of reproducing the observed lens statistics in the Hubble Space Telescope Snapshot Survey (HSTSS).