Determining Cosmological Parameters through Statistics of Redshifts of Lens Galaxies

For known gravitational lens systems the redshift distribution of the lenses is compared with theoretical expectations for about ten thousand Friedmann-Lemaître cosmological models, which more than cover the range of possible cases. The comparison is used for assigning a relative probability to each of the models. The entire procedure is repeated for different values of the inhomogeneity parameter eta as well as H_0 and the limiting spectroscopic magnitude, which are important for selection effects. The dependence on these three parameters is examined in more detail for lambda=0 and k=0.

The previous result of other authors that this method is a good probe for lambda_0 is confirmed, but it appears that the low probability of models with large lambda_0 values reported by these authors may be due to a selection effect. The power of this method to discriminate between cosmological models can be improved dramatically if more gravitational lens systems are found