A roadmap to cosmological parameter analysis with thirdorder shear statistics. I. Modelling and validation
Abstract
In this work, which is the first of a series to prepare a cosmological parameter analysis with thirdorder cosmic shear statistics, we model both the shear threepoint correlation functions Γ^{(i)} and the thirdorder aperture statistics {<{{\mathcal{M}^3_ap}}>} from the B IHALOFIT bispectrum model and validate these statistics with a series of Nbody simulations. We then investigate how to bin the shear threepoint correlation functions to achieve an unbiased estimate for thirdorder aperture statistics in real data. Finally, we perform a cosmological parameter analysis on KiDS1000like mock data with second and thirdorder statistics. In the absence of systematic effects, 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 Ω_{m}σ_{8} plane by a factor of 5.9 with respect to an analysis with only secondorder shear statistics.
Our modelling pipeline is publicly available at https://github.com/sheydenreich/threepoint/releases/
 Publication:

Astronomy and Astrophysics
 Pub Date:
 April 2023
 DOI:
 10.1051/00046361/202244820
 arXiv:
 arXiv:2208.11686
 Bibcode:
 2023A&A...672A..44H
 Keywords:

 gravitational lensing: weak;
 cosmological parameters;
 largescale structure of Universe;
 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 updated acknowledgements