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arXiv · 2112.05155

Weak Lensing Trispectrum and Kurt-Spectra

Dipak Munshi·Hayden Lee·Cora Dvorkin·Jason D. McEwen
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Abstract

We introduce two kurt-spectra to probe fourth-order statistics of weak lensing convergence maps. Using state-of-the-art numerical simulations, we study the shapes of these kurt-spectra as a function of source redshifts and smoothing angular scales. We employ a pseudo-$C_{\ell}$ approach to estimate the spectra from realistic convergence maps in the presence of an observational mask and noise for stage-IV large-scale structure surveys. We compare these results against theoretical predictions calculated using the FFTLog formalism, and find that a simple nonlinear clustering model-the hierarchical ansatz-can reproduce the numerical trends for the kurt-spectra in the nonlinear regime. In addition, we provide estimators for beyond fourth-order spectra where no definitive analytical results are available, and present corresponding results from numerical simulations.

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Dipak Munshi, Hayden Lee, Cora Dvorkin, Jason D. McEwen. 2021-12-09. Weak Lensing Trispectrum and Kurt-Spectra. https://doi.org/10.1088/1475-7516%2F2022%2F11%2F020

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