Perturbation theory for the redshift-space matter power spectra after reconstruction

TL;DR

This paper derives a one-loop perturbative model for the redshift-space matter power spectrum after reconstruction, showing improved agreement with simulations and reduced errors in cosmic growth rate measurements.

Contribution

It introduces a novel one-loop perturbation theory for the reconstructed matter power spectrum in redshift space, enhancing modeling accuracy.

Findings

Reconstruction reduces nonlinear mode-coupling effects.

Reconstructed spectra agree with one-loop theory at higher wavenumbers.

Error in cosmic growth rate measurement decreases by half after reconstruction.

Abstract

We derive the one-loop perturbative formula of the redshift-space matter power spectrum after density field reconstruction in the Zeldovich approximation. We find that the reconstruction reduces the amplitudes of nonlinear one-loop perturbative terms significantly by partially erasing the nonlinear mode-coupling between density and velocity fields. In comparison with N-body simulations, we find that both the monopole and quadrupole spectra of reconstructed matter density fields agree with the one-loop perturbation theory up to higher wavenumber than those before reconstruction. We also evaluate the impact on cosmic growth rate assuming the survey volume and the number density like the Baryon Oscillation Spectroscopic Survey and find that the total error, including statistical and systematic ones due to one-loop approximation, decreases by half.