A&A 382, 787-791 (2002)
The Dyer-Roeder distance-redshift relation in inhomogeneous universesE. Mörtsell
Department of Physics, Stockholm University, 106 91 Stockholm, Sweden
(Received 25 September / Accepted 16 November 2001)
Using Monte-Carlo methods, we determine the best-fit value of the homogeneity parameter in the Dyer-Roeder distance-redshift relation for a variety of redshifts, inhomogeneity models and cosmological parameter values. The relation between and the fraction of compact objects, , is found to be approximately linear. This relation can be parametrized with reasonable accuracy for all cases treated in this paper by where .
Key words: cosmology: theory -- gravitational lensing
© ESO 2002