Speaker
Description
The Cosmological Principle, which assumes both homogeneity and isotropy on large scales, is a cornerstone of the standard model of cosmology and shapes how we view the Universe and our place within it. It is imperative, then, to devise multiple observational tests which can identify and quantify possible violations of this foundational principle. One possible method of probing large-scale anisotropies involves the use of weak gravitational lensing. Previously, we demonstrated how cross-correlations between $E$- and $B$-modes in cosmic shear can reveal signatures of anisotropy at late times. In this talk, I will present a complementary approach: using cross-correlations between Cosmic Microwave Background (CMB) lensing convergence and cosmic shear $B$-modes measured from galaxy shapes. Our analysis shows that this probe can reach percent-level sensitivity to anisotropy with data from a Euclid-like survey, with most of its constraining power deriving from large angular scales ($\ell\lesssim 200$).