2014/05/22 by Raul E. Angulo, Stefan Hilbert · 1 citation
Physics and Astronomy · #astro-ph.CO #astro-ph.GA
paper · pdf · doi:10.1093/mnras/stv050
12 pages, 8 figures
arxiv created 2014/05/22 · arxiv updated 2015/06/19
We explore the cosmological constraints from cosmic shear using a new way of modelling the non-linear matter correlation functions. The new formalism extends the method of Angulo & White (2010), which manipulates outputs of N-body simulations to represent the three-dimensional nonlinear mass distribution in different cosmological scenarios. We show that predictions from our approach for shear two-point correlations at 1 to 300 arcmin separations are accurate at the ∼10% level, even for extreme changes in cosmology. For moderate changes, with target cosmologies similar to that preferred by analyses of recent Planck data, the accuracy is close to ∼5%. We combine this approach with a MonteCarlo Markov Chain sampler to explore constraints on a ΛCDM model from the shear correlation functions measured in the Canada-France Hawaii Telescope Lensing Survey (CFHTLenS). We obtain constraints on the parameter combination σ8 (Ωm/0.27)0.6 = 0.801 ± 0.028. Combined with results from CMB data, we obtain marginalised constraints on σ8 = 0.81 ± 0.01 and Ωm = 0.29 ± 0.01. These results are fully compatible with previous analyses, which supports the validity of our approach. We discuss the advantages of our method and the potential it offers, including a path to incorporate in detail the effects of baryons, among others effects, in future high-precision cosmological analyses.