Weak Lensing Skew-Spectrum

Abstract

We introduce the skew-spectrum statistic for weak lensing convergence $\kappa$ maps and test it against state-of-the-art high-resolution all-sky numerical simulations. We perform the analysis as a function of source redshift and smoothing angular scale for individual tomographic bins. We also analyse the cross-correlation between different tomographic bins. We compare the numerical results to fitting-functions used to model the bispectrum of the underlying density field as a function of redshift and scale. We derive a closed form expression for the skew-spectrum for gravity-induced secondary non-Gaussianity. We also compute the skew-spectrum for the projected $\kappa$ inferred from Cosmic Microwave Background (CMB) studies. As opposed to the low redshift case we find the post-Born corrections to be important in the modelling of the skew-spectrum for such studies. We show how the presence of a mask and noise can be incorporated in the estimation of a skew-spectrum.

16 pages, 11 figures

References in corpus (9)

• Beyond the Cosmological Standard Model
• Massive neutrinos and cosmology
• Cosmology with Weak Lensing Surveys
• Full-sky Gravitational Lensing Simulation for Large-area Galaxy Surveys and Cosmic Microwave Background Experiments
• CMB Constraints on Primordial non-Gaussianity from the Bispectrum (f_{NL}) and Trispectrum (g_{NL} and τ_{NL}) and a New Consistency Test of Single-Field Inflation
• KiDS-450: Cosmological Constraints from Weak Lensing Peak Statistics-I: Inference from Analytical Prediction of High Signal-to-Noise Ratio Convergence Peaks
• Near optimal bispectrum estimators for large-scale structure
• Cosmology with Phase Statistics: Parameter Forecasts and Detectability of BAO
• Consistency Relations in Effective Field Theory

Cited by in corpus (8)

• Nuw CDM cosmology from the weak lensing convergence PDF
• Cosmological Information in Skew Spectra of Biased Tracers in Redshift Space
• The integrated angular bispectrum of weak lensing
• Skewing the CMB$\times$LSS: a Fast Method for Bispectrum Analysis
• Weak Lensing Trispectrum and Kurt-Spectra
• Position-Dependent Correlation Function of Weak Lensing Convergence
• A New Estimator for Phase Statistics
• On Weak Lensing Response Functions