Non-Perturbative Effects of Geometry in Wide-Angle Redshift Distortions

TL;DR

This paper derives comprehensive formulas for the linear two-point correlation function in redshift space, incorporating large angle effects and a previously neglected geometric term, leading to more accurate modeling aligned with simulations.

Contribution

It introduces a non-perturbative geometric correction to the linear correlation function calculations, improving accuracy in redshift space distortion modeling.

Findings

Significant correction to previous correlation function expressions.

Excellent agreement with Hubble Volume Simulation measurements.

Highlights importance of geometric terms in large-angle redshift distortions.

Abstract

We use the formalism of Szapudi(2004} to derive full explicit expressions for the linear two-point correlation function, including redshift space distortions and large angle effects. We take into account a non-perturbative geometric term in the Jacobian, which is still linear in terms of the dynamics. This term had been identified previously (Kaiser 1987,Hamilton and Culhane 1996), but has been neglected in all subsequent explicit calculations of the linear redshift space two-point correlation function. Our results represent a significant correction to previous explicit expressions and are in excellent agreement with our measurements in the Hubble Volume Simulation.