A roadmap to cosmological parameter analysis with third-order shear statistics. I. Modelling and validation
Abstract
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 Γ(i) and the third-order aperture statistics {<{{\mathcal{M}^3_ap}}>} from the B IHALOFIT 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. 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 S8 and increases the figure of merit in the Ωm-σ8 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/- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- April 2023
- DOI:
- 10.1051/0004-6361/202244820
- arXiv:
- arXiv:2208.11686
- Bibcode:
- 2023A&A...672A..44H
- Keywords:
-
- gravitational lensing: weak;
- cosmological parameters;
- large-scale structure of Universe;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- updated acknowledgements