Dark Energy Survey Year 3 results: Cosmology with moments of weak lensing mass maps - Validation on simulations

Gatti, M. and Chang, C and Desai, Shantanu and et al, . (2020) Dark Energy Survey Year 3 results: Cosmology with moments of weak lensing mass maps - Validation on simulations. Oxford University Press.

Text
Monthly_Notices_.pdf - Published Version
Available under License Creative Commons Attribution.
Download (4MB)

Abstract

We present a simulated cosmology analysis using the second and third moments of the weak lensing mass (convergence) maps. The second moment, or variances, of the convergence as a function of smoothing scale contains information similar to standard shear two-point statistics. The third moment, or the skewness, contains additional non-Gaussian information. The analysis is geared towards the third year (Y3) data from the Dark Energy Survey (DES), but the methodology can be applied to other weak lensing data sets. We present the formalism for obtaining the convergence maps from the measured shear and for obtaining the second and third moments of these maps given partial sky coverage. We estimate the covariance matrix from a large suite of numerical simulations. We test our pipeline through a simulated likelihood analyses varying 5 cosmological parameters and 10 nuisance parameters and identify the scales where systematic or modelling uncertainties are not expected to affect the cosmological analysis. Our simulated likelihood analysis shows that the combination of second and third moments provides a 1.5 per cent constraint on S8 σ8(ωm/0.3)0.5 for DES Year 3 data. This is 20 per cent better than an analysis using a simulated DES Y3 shear two-point statistics, owing to the non-Gaussian information captured by the inclusion of higher order statistics. This paper validates our methodology for constraining cosmology with DES Year 3 data, which will be presented in a subsequent paper. © 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.

[error in script]

IITH Creators: