کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1771193 | 1020736 | 2010 | 12 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Breaking the degeneracy: Optimal use of three-point weak lensing statistics Breaking the degeneracy: Optimal use of three-point weak lensing statistics](/preview/png/1771193.png)
We study the optimal use of three-point statistics in the analysis of weak lensing by large-scale structure. The three-point statistics have long been advocated as a powerful tool to break measured degeneracies between cosmological parameters. Using ray-tracing simulations, incorporating important survey features such as a realistic depth-dependent redshift distribution, we find that a joint two- and three-point correlation function analysis is a much stronger probe of cosmology than the skewness statistic. We compare different observing strategies, showing that for a limited survey time there is an optimal depth for the measurement of three-point statistics, which balances statistical noise and cosmic variance against signal amplitude. We find that the chosen CFHTLS observing strategy was optimal and forecast that a joint two- and three-point analysis of the completed CFHTLS-Wide will constrain the amplitude of the matter power spectrum σ8σ8 to 10% and the matter density parameter ΩmΩm to 17%, a factor of 2.5 improvement on the two-point analysis alone. Our error analysis includes all non-Gaussian terms, finding that the coupling between cosmic variance and shot noise is a non-negligible contribution which should be included in any future analytical error calculations.
Journal: Astroparticle Physics - Volume 32, Issue 6, January 2010, Pages 340–351