EDP Sciences
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Volume 382, Number 3, February II 2002
Page(s) 787 - 791
Section Cosmology
DOI http://dx.doi.org/10.1051/0004-6361:20011653

A&A 382, 787-791 (2002)
DOI: 10.1051/0004-6361:20011653

The Dyer-Roeder distance-redshift relation in inhomogeneous universes

E. 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 $\alpha$ in the Dyer-Roeder distance-redshift relation for a variety of redshifts, inhomogeneity models and cosmological parameter values. The relation between $\alpha$ and the fraction of compact objects, $f_{\rm p}$, is found to be approximately linear. This relation can be parametrized with reasonable accuracy for all cases treated in this paper by $1-\alpha =a\cdot f_{\rm p},$ where $a\approx 0.6$.

Key words: cosmology: theory -- gravitational lensing

© ESO 2002