Abstract

Cosmological observables such as galaxy statistics are mapped in terms of angular positions on the sky and redshifts. While the traditional Fourier analysis has been widely used for small survey volumes, near-future galaxy surveys will map galaxies at wider angles and deeper in redshift, necessitating a full-sky formalism for analyzing angular correlations of galaxies. However, data analysis in angular space has so far proved challenging due to the numerical difficulty of evaluating 2D projection integrals. In this talk, I will describe a new efficient method for computing cosmological angular correlations that bypasses this difficulty. This approach does not only accelerate the computation of galaxy angular power spectra, but also that of bispectra and trispectra relevant for constraining primordial non-Gaussianity. A particularly interesting application is to study the cross-correlations between galaxies and the CMB lensing—I will present forecasted constraints on cosmological parameters based on the new technique.