## Abstract

Analysing future weak-lensing data sets from KIDS, Dark Energy Survey (DES), LSST, Euclid and WFIRST requires precise predictions for the weak-lensing measures. In this paper, we present a weak-lensing prediction code based on the Coyote Universe emulator. The Coyote Universe emulator predicts the (non-linear) power spectrum of density fluctuations (P_{δ}) to high accuracy for k∈[0.002; 3.4]hMpc^{-1} within the redshift interval z∈[0; 1]; outside this regime, we extend P_{δ} using a modified halofit code. This pipeline is used to calculate various second-order cosmic shear statistics, e.g., shear power spectrum, shear-shear correlation function, ring statistics and Complete Orthogonal Set of EB-mode Integrals (COSEBIs), and we examine how the upper limit in k (and z), to which P_{δ} is known, impacts on these statistics. For example, we find that k_{max}∼ 8hMpc^{-1} causes a bias in the shear power spectrum at ℓ∼ 4000 that is comparable to the statistical errors (intrinsic shape noise and cosmic variance) of a DES-like survey, whereas for LSST-like errors k_{max}∼ 15hMpc^{-1} is needed to limit the bias at ℓ∼ 4000. For the most recently developed second-order shear statistics, the COSEBIs, we find that nine modes can be calculated accurately knowing P_{δ} to k_{max}= 10hMpc^{-1}. The COSEBIs allow for an EB-mode decomposition using a shear-shear correlation function measured over a finite range, thereby avoiding any EB-mode mixing due to finite survey size. We perform a detailed study in a five-dimensional parameter space in order to examine whether all cosmological information is captured by these nine modes with the result that already 7-8 modes are sufficient.

Original language | English (US) |
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Pages (from-to) | 536-544 |

Number of pages | 9 |

Journal | Monthly Notices of the Royal Astronomical Society |

Volume | 418 |

Issue number | 1 |

DOIs | |

State | Published - Nov 2011 |

Externally published | Yes |

## Keywords

- Cosmology: theory
- Large-scale structure of Universe

## ASJC Scopus subject areas

- Astronomy and Astrophysics
- Space and Planetary Science