Modeling the large-scale redshift-space 3-point correlation function of galaxies

TL;DR

This paper develops a large-scale galaxy 3-point correlation function model in redshift space using perturbation theory, aiding in BAO-based distance measurements and including bias effects from baryon-dark matter velocities.

Contribution

It introduces a configuration-space model of the galaxy 3PCF with redshift-space distortions and a new scheme for fast predictions, enhancing cosmological parameter analysis.

Findings

RSD primarily causes a scale-independent renormalization of the 3PCF (~1.8)

First redshift-space biasing treatment involving baryon-dark matter relative velocity

Efficient computational scheme for rapid 3PCF predictions

Abstract

We present a configuration-space model of the large-scale galaxy 3-point correlation function (3PCF) based on leading-order perturbation theory and including redshift space distortions (RSD). This model should be useful in extracting distance-scale information from the 3PCF via the Baryon Acoustic Oscillation (BAO) method. We include the first redshift-space treatment of biasing by the baryon-dark matter relative velocity. Overall, on large scales the effect of RSD is primarily a renormalization of the 3PCF that is roughly independent of both physical scale and triangle opening angle; for our adopted $\Omega_{\rm m}$ and bias values, the rescaling is a factor of $\sim 1.8$. We also present an efficient scheme for computing 3PCF predictions from our model, important for allowing fast exploration of the space of cosmological parameters in future analyses.