Title: Squeezing cosmological information out of weak lensing bispectrum
Abstract: I will discuss how to use the statistics called Integrated Bispectrum (IB) to probe the gravity-induced non-Gaussianity at the level of the bispectrum from weak lensing maps. I will discuss how to generalize the concept of the IB to spherical coordinates, and to three-dimensions (3D) using a spherical-Bessel decomposition. These results will next be connected to the response function approach. I will introduce the concept of squeezed three-point correlation functions (3PCF) for convergence maps and relate them to the IB defined in the Fourier domain. I will demonstrate how IB can be computed using a variety of analytical approaches including the ones based on Tree-Level Standard Perturbation Theory (SPT), Effective Field Theory (EFT), Halo models and models based on the Separate Universe approach. Generalization to include tomographic bins, external data sets and Bayesian estimators will be discussed. I will also show results from the Euclid Flagship simulations to test analytical results as a function of redshift and wave number. Generalization to shear maps and construction of squeezed limits of EEE, BBB, EEB and EEB bispectra will also be discussed. I also plan to show how external data sets, e.g. $y$-parameter maps from thermal Sunyaev-Zel’dovich (tSZ) observations, can be used to construct the squeezed limits of mixed IB involving y and convergence fields.