Probing 3-point Intrinsic Alignment Correlations Using Self-Calibration Technique

Incorporating three-point correlations alongside conventional two-point cosmic shear correlations can significantly enhance the accuracy of cosmological parameter estimation. However, the intrinsic alignment (IA) of galaxies poses a substantial challenge to the precision of cosmic shear surveys. A comprehensive understanding of three-point IA correlations is essential to obtain a pure cosmic shear signal beyond two-point statistics. We propose an efficient technique tailored for the non-linear alignment (NLA) model to extract all the three-point IA correlations from photometric surveys using the self-calibration method. Our approach computes the necessary two-point IA correlations as an intermediate step, ultimately constructing three-point IA correlations by leveraging information from cosmic shear surveys, two-point and three-point galaxy clustering correlations, and two-point galaxy-galaxy lensing correlations. Our method is suitable of producing three-point IA correlations in both harmonic and configuration spaces.