Weak lensing power spectra for precision cosmology: Multiple-deflection, reduced shear and lensing bias corrections

摘要: It is usually assumed that the ellipticity power spectrum measured in weak lensing observations can be expressed as an integral over underlying matter spectrum. This true at second order gravitational potential. We extend standard calculation, constructing all corrections to fourth There are four types of corrections: shear due multiple-deflections; fact shape distortions probe reduced $\gamma/(1-\kappa)$ rather than itself; associated with non-linear conversion mean ellipticity; and observational galaxy selection measurement based on brightnesses sizes which have been (de)magnified by lensing. show how previously considered correspond terms our analysis, highlight new were not identified. All correction given explicitly integrals spectrum, bispectrum, trispectrum, numerically evaluated for case sources z=1. find agreement previous works ${\mathcal O}(\Phi^3)$ terms. ambitious future surveys, O}(\Phi^4)$ affect ~ 1-5 $\sigma$ level; they will thus need accounted for, but unlikely represent a serious difficulty cosmological probe.