Observed galaxy number counts on the lightcone up to second order: I. Main result

Abstract

We present the galaxy number overdensity up to second order in redshift space on cosmological scales for a concordance model. The result contains all general relativistic effects up to second order that arise from observing on the past light cone, including all redshift effects, lensing distortions from convergence and shear, and contributions from velocities, Sachs-Wolfe, integrated SW and time-delay terms. This result will be important for accurate calculation of the bias on estimates of non-Gaussianity and on precision parameter estimates, introduced by nonlinear projection effects.

7 pages, 1 figure. In the previous v4 (and in the published paper), we mistakenly omitted some post-Born terms. This error has been corrected here and in the companion paper 1406.0319v4. Our results are now in agreement, in the appropriate limit, with those of arXiv:1606.02113