Cosmological constraints from the CFHTLenS shear measurements using a new, accurate and flexible way of predicting nonlinear mass clustering

Raul E. Angulo; Stefan Hilbert

doi:10.1093/mnras/stv050

paper

Cosmological constraints from the CFHTLenS shear measurements using a new, accurate and flexible way of predicting nonlinear mass clustering

arXiv:1405.5888 · doi:10.1093/mnras/stv050

Abstract

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 $\sim 10$ \% 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 $\sim 5$ \%. We combine this approach with a MonteCarlo Markov Chain sampler to explore constraints on a $Λ$ CDM model from the shear correlation functions measured in the Canada-France Hawaii Telescope Lensing Survey (CFHTLenS). We obtain constraints on the parameter combination $σ_{8} (Ω_{m} /0.27)^{0.6} = 0.801 \pm 0.028$ . Combined with results from CMB data, we obtain marginalised constraints on $σ_{8} = 0.81 \pm 0.01$ and $Ω_{m} = 0.29 \pm 0.01$ . 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.

arXiv comment12 pages, 8 figures

Cosmological constraints from the CFHTLenS shear measurements using a new, accurate and flexible way of predicting nonlinear mass clustering

Abstract

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