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 $\Gamma^{(i)}$ and the thirdorder aperture statistics $\langle\mathcal{M}_\mathrm{ap}^3\rangle$ from the BiHalofit 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. 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 figureofmerit in the $\Omega_\mathrm{m}$$\sigma_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:

arXiv eprints
 Pub Date:
 August 2022
 arXiv:
 arXiv:2208.11686
 Bibcode:
 2022arXiv220811686H
 Keywords:

 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 updated acknowledgements