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

Understand

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.