Tuesday, July 24, 2012

Joint Analysis of Gravitational Lensing, Clustering and Abundance: Toward the Unification of Large-Scale Structure Analysis. (arXiv:1207.2471v1 [astro-ph.CO])

Joint Analysis of Gravitational Lensing, Clustering and Abundance: Toward the Unification of Large-Scale Structure Analysis. (arXiv:1207.2471v1 [astro-ph.CO]):
We explore three different methods based on weak lensing to extract
cosmological constraints from the large-scale structure. In the first approach
(method I), small-scale galaxy lensing measurements of their halo mass provide
a constraint on the halo bias, which can be combined with the large-scale
galaxy clustering to measure the dark matter clustering. In the second approach
(method II), large-scale galaxy clustering and large-scale galaxy-galaxy
lensing can be combined into a direct measurement of the dark matter
clustering. These two methods can be combined into one method I+II to make use
of lensing measurements on all scales. In the third approach (method III), we
add abundance information to the method I. We explore the statistical power of
these three approaches as a function of galaxy luminosity to investigate the
optimal mass range for each method and their cosmological constraining power.
In the case of the SDSS, we find that the three methods give comparable
constraints, but not in the same mass range: the method II works best for halos
of M~10^13 Msun, and the methods I and III work best for halos of M~10^14 Msun.
We discuss the robustness of each method against various systematics.
Furthermore, we extend the analysis to the future large-scale galaxy surveys
and find that the cluster abundance method is not superior to the combined
method I+II, both in terms of statistical power and robustness against
systematic errors. The cosmic shear-shear correlation analysis in the future
surveys yields constraints as strong as the combined method, but suffer from
additional systematic effects. We thus advocate the combined analysis of
clustering and lensing (method I+II) as a powerful alternative to other
large-scale probes. Our analysis provides a guidance to observers planning
large-scale galaxy surveys such as the DES, Euclid, and the LSST.

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