Speaker
Description
The integrated 3-point correlation function (i3PCF) is a higher-order statistic (beyond traditional 2-point methods) that can be measured directly from weak lensing cosmic shear data by correlating local 1-point aperture mass statistics with local shear 2-point correlation functions (2PCF) measured within well-defined patches across a galaxy survey footprint. We have developed an accurate theoretical model using the response function approach to perturbation theory to calculate the i3PCF, included several known lensing systematic effects in our modelling and made use of machine learning emulator techniques to perform rapid MCMC analyses. We have measured and analysed the i3PCF in the blinded cosmic shear dataset of the Dark Energy Survey Year 3 (DESY3) data release and found that the addition of the i3PCF brings significant improvements on cosmological parameters relative to 2PCFs alone. Based on the encouraging results, we have extended our framework to propose the integrated 3-point cross-correlation functions of lensing and projected galaxy density fields. We forecast that these new higher-order lensing $\times$ galaxy clustering statistics hold the potential to bring further interesting improvements not only on cosmological but also on galaxy bias parameters.
