The Full-Sky Angular Bispectrum in Redshift Space
  We compute the redshift-dependent angular bispectrum of galaxy number counts
at tree-level, including nonlinear clustering bias and estimating numerically
for the first time the effect of redshift space distortions (RSD). We show that
for narrow redshift bins the amplitude of nonlinear RSD is comparable with the
matter density perturbations. While our numerical results only include terms
relevant on sub-horizon scales, the formalism can readily be extended to the
full tree-level bispectrum. Our approach does not rely on the flat-sky
approximation and it can be easily generalized to different sources by
including the appropriate bias expansion. We test the accuracy of Limber
approximation for different z-bins. We highlight the subtle but relevant
differences in the angular bispectrum of galaxy number counts with respect to
CMB, due to the different scale dependence of perturbations. Our formalism can
also be directly applied to the angular HI intensity mapping bispectrum.
