A redshift-distortion-free correlation function at third order in the non-linear regime

Abstract

The zeroth-order component of the cosine expansion of the projected three-point correlation function is proposed for the clustering analysis of cosmic large-scale structure. These functions are third-order statistics but can be measured similarly to the projected two-point correlations. Numerical experiments with N-body simulations indicate that the advocated statistics are redshift distortion free within 10 per cent in the non-linear regime on scales of ~0.2-10h-1Mpc. The halo model prediction of the zeroth-order component of the projected three-point correlation function agrees with simulations within ~10 per cent. This lays the ground for using these functions to perform joint analyses with the projected two-point correlation functions, exploring galaxy clustering properties in the framework of the halo model and relevant extensions. © 2011 The Authors. Monthly Notices of the Royal Astronomical Society © 2011 RAS.