Volume 403, Number 3, June I 2003
|Page(s)||817 - 828|
|Published online||23 May 2003|
Improving the accuracy of cosmic magnification statistics
Max-Planck-Institut für Astrophysik, PO Box 1317, 85741 Garching, Germany
2 Institut d'Astrophysique de Paris, 98 bis Bld Arago, 75014, Paris, France
3 National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588, Japan
4 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge MA 02138, USA
Corresponding author: B. Ménard, email@example.com
Accepted: 17 March 2003
The systematic magnification of background sources by the weak gravitational-lensing effects of foreground matter, also called cosmic magnification, is becoming an efficient tool both for measuring cosmological parameters and for exploring the distribution of galaxies relative to the dark matter. We extend here the formalism of magnification statistics by estimating the contribution of second-order terms in the Taylor expansion of the magnification and show that the effect of these terms was previously underestimated. We test our analytical predictions against numerical simulations and demonstrate that including second-order terms allows the accuracy of magnification-related statistics to be substantially improved. We also show, however, that both numerical and analytical estimates can provide only lower bounds to real correlation functions, even in the weak lensing regime. We propose to use count-in-cells estimators rather than correlation functions for measuring cosmic magnification since they can more easily be related to correlations measured in numerical simulations.
Key words: cosmology: gravitational lensing / cosmology: large-scale structure of Universe
© ESO, 2003
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.