Discreteness Effects in the Post-Reconstruction Galaxy Power Spectrum

TL;DR

This paper develops a comprehensive theoretical model for the post-reconstruction galaxy power spectrum, incorporating discrete shot noise effects, non-linear damping, and RSD, enhancing analysis accuracy for cosmological surveys.

Contribution

It introduces a novel model that explicitly includes discrete effects and IR damping in the post-reconstruction galaxy power spectrum for RSD studies.

Findings

Calculated discrete shot noise effects within 1-loop perturbation theory.

Modeled non-linear damping of BAO signal with IR effects.

Provided a comprehensive framework for post-reconstruction RSD analysis.

Abstract

Recent studies have increasingly recognized the value of analyzing the post-reconstruction galaxy power spectrum for investigations into redshift space distortion (RSD) effects. In this paper, we present a novel theoretical model for the post-reconstruction galaxy power spectrum, designed for RSD analyses. In particular, we emphasize the importance of accounting for discrete effects arising from the reconstruction displacement vector, which have been overlooked. We specifically calculate these discrete effects, i.e., shot noise terms, within the framework of standard perturbation theory at the 1-loop level. In addition, we adopt a formulation that accounts for infrared (IR) effects to accurately model the non-linear damping of the Baryon Acoustic Oscillation (BAO) signal. Our model comprehensively integrates key physical phenomena relevant to the post-reconstruction galaxy power spectrum, such as gravitational non-linearities, RSD effects, bias effects, reconstruction effects, reconstruction-specific shot-noise effects, and the non-linear damping of the reconstructed BAO signal, thereby making it applicable to post-reconstruction RSD analyses.