A roadmap to cosmological parameter analysis with third-order shear statistics I: Modelling and validation [CEA]

http://arxiv.org/abs/2208.11686


In this work, which is the first of a series to prepare a cosmological parameter analysis with third-order cosmic shear statistics, we model both the shear three-point correlation functions $\Gamma^{(i)}$ and the third-order aperture statistics $\langle\mathcal{M}\mathrm{ap}^3\rangle$ from the BiHalofit bispectrum model and validate these statistics with a series of N-body simulations.
We then investigate how to bin the shear three-point correlation functions to achieve an unbiased estimate for third-order aperture statistics in real data.
Finally, we perform a cosmological parameter analysis on KiDS1000-like mock data with second- and third-order statistics. We recover all cosmological parameters with very little bias. Furthermore, we find that a joint analysis almost doubles the constraining power on $S_8$ and increases the figure-of-merit in the $\Omega
\mathrm{m}$-$\sigma_8$ plane by a factor of 5.9 with respect to an analysis with only second-order shear statistics.
Our modelling pipeline is publicly available at https://github.com/sheydenreich/threepoint/releases/.

Read this paper on arXiv…

S. Heydenreich, L. Linke, P. Burger, et. al.
Thu, 25 Aug 22
18/43

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