An analytic model for redshift-space distortions

TL;DR

This paper develops an advanced analytic model for redshift-space distortions using an extended CLPT formalism, improving predictions of galaxy clustering and velocities, crucial for testing cosmological theories.

Contribution

It extends the CLPT formalism to better predict pairwise velocities and clustering statistics, achieving higher accuracy than standard perturbation theory.

Findings

Predictions outperform standard perturbation theory in many cases.

Achieves 2-4% accuracy for monopole and quadrupole correlation functions.

Provides detailed analysis of 2D correlation contours and clustering wedges.

Abstract

Understanding the formation and evolution of large-scale structure is a central problem in cosmology and enables precise tests of General Relativity on cosmological scales and constraints on dark energy. An essential ingredient is an accurate description of the pairwise velocities of biased tracers of the matter field. In this paper we compute the first and second moments of the pairwise velocity distribution by extending the Convolution Lagrangian Perturbation theory (CLPT) formalism of Carlson et al. (2012). Our predictions outperform standard perturbation theory calculations in many cases when compared to statistics measured in N-body simulations. We combine the CLPT predictions of real-space clustering and velocity statistics in the Gaussian streaming model of Reid & White (2011) to obtain predictions for the monopole and quadrupole correlation functions accurate to 2 and 4 per cent respectively down to <25Mpc/h for halos hosting the massive galaxies observed by SDSS-III BOSS. We also discuss contours of the 2D correlation function and clustering "wedges". We generalize the scheme to cross-correlation functions.