Capturing statistical isotropy violation with rotational averages
The work introduces a geometric approach to measure statistical isotropy violations (nSI) in CMB data by averaging correlation functions over all possible rotations. This method aims to provide a physical, real-space interpretation of harmonic space measures like BipoSH coefficients. It allows for direct extraction of anisotropy information from temperature correlations at specific multipoles, bypassing complex harmonic space computations and partial-sky effects.