A roadmap to cosmological parameter analysis with third-order shear statistics III: Efficient estimation of third-order shear correlation functions and an application to the KiDS-1000 data
| Autor: | Porth, Lucas, Heydenreich, Sven, Burger, Pierre, Linke, Laila, Schneider, Peter |
|---|---|
| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | A&A 689, A227 (2024) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1051/0004-6361/202347987 |
| Popis: | Third-order lensing statistics contain a wealth of cosmological information that is not captured by second-order statistics. However, the computational effort for estimating such statistics on forthcoming stage IV surveys is prohibitively expensive. We derive and validate an efficient estimation procedure for the three-point correlation function (3PCF) of polar fields such as weak lensing shear. We then use our approach to measure the shear 3PCF and the third-order aperture mass statistics on the KiDS-1000 survey. We construct an efficient estimator for third-order shear statistics which builds on the multipole decomposition of the 3PCF. We then validate our estimator on mock ellipticity catalogs obtained from $N$-body simulations. Finally, we apply our estimator to the KiDS-1000 data and present a measurement of the third-order aperture statistics in a tomographic setup. Our estimator provides a speedup of a factor of $\sim$ 100-1000 compared to the state-of-the-art estimation procedures. It is also able to provide accurate measurements for squeezed and folded triangle configurations without additional computational effort. We report a significant detection of the tomographic third-order aperture mass statistics in the KiDS-1000 data $(\mathrm{S/N}=6.69)$. Our estimator will make it computationally feasible to measure third-order shear statistics in forthcoming stage IV surveys. Furthermore, it can be used to construct empirical covariance matrices for such statistics. Comment: 15 pages, 8 figures + appendices |
| Databáze: | arXiv |
| Externí odkaz: |
|