Primordial Non-Gaussianity and the Statistics of Weak Lensing and other Projected Density Fields

Abstract

Estimators for weak lensing observables such as shear and convergence generally have non-linear corrections, which, in principle, make weak lensing power spectra sensitive to primordial non-Gaussianity. In this paper, we quantitatively evaluate these contributions for weak lensing auto- and cross-correlation power spectra, and show that they are strongly suppressed by projection effects. This is a consequence of the central limit theorem, which suppresses departures from Gaussianity when the projection reaches over several correlation lengths of the density field, L_P~55 [Mpc/h]. Furthermore, the typical scales that contribute to projected bispectra are generally smaller than those that contribute to projected power spectra. Both of these effects are not specific to lensing, and thus affect the statistics of non-linear tracers (e.g., peaks) of any projected density field. Thus, the clustering of biased tracers of the three-dimensional density field is generically more sensitive to non-Gaussianity than observables constructed from projected density fields.

10 pages, 6 figures

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Cited by in corpus (11)

• Large-Scale Galaxy Bias
• Imprint of inflation on galaxy shape correlations
• Cosmic Rulers
• Large-Scale Structure Observables in General Relativity
• The Hunt for Primordial Interactions in the Large Scale Structures of the Universe
• Cosmic shear bispectrum from second-order perturbations in General Relativity
• The squeezed matter bispectrum covariance with responses
• Galaxy shape statistics in the effective field theory
• A weak lensing view on primordial non-Gaussianities
• A test of the Suyama-Yamaguchi inequality from weak lensing
• Superclustering with the Atacama Cosmology Telescope and Dark Energy Survey: II. Anisotropic large-scale coherence in hot gas, galaxies, and dark matter