Measuring the redshift-space distortions by cross-correlating the density fields before and after reconstruction

TL;DR

This paper develops a theoretical model for the cross-power spectrum of galaxy density fields before and after BAO reconstruction to accurately measure redshift-space distortions, validated with simulations.

Contribution

The paper introduces a new theoretical model for the cross-power spectrum that improves RSD parameter extraction, validated against high-resolution simulations.

Findings

Model accurately predicts the cross-power spectrum.

Validated robustness against N-body simulations.

Enables improved cosmological parameter estimation.

Abstract

In this work, we develop a theoretical model for the cross-power spectrum of the galaxy density field before and after standard baryonic acoustic oscillation (BAO) reconstruction. Using this model, we extract the redshift-space distortion (RSD) parameter from the cross-power spectrum. The model is validated against a suite of high-resolution $N$-body simulations, demonstrating its accuracy and robustness for cosmological analyses.