The VIMOS Public Extragalactic Redshift Survey (VIPERS). The matter density and baryon fraction from the galaxy power spectrum at redshift $0.6<z<1.1$

TL;DR

This study measures the galaxy power spectrum at redshifts 0.6 to 1.1 using VIPERS data, providing constraints on matter density and baryon fraction that support the consistency of the b4bcm model across cosmic time.

Contribution

It presents the first measurement of the galaxy power spectrum beyond redshift 1, extending high-redshift cosmological constraints using VIPERS data.

Findings

Results align with b4bcm model predictions

Matter density parameter a_M h = 0.227^{+0.063}_{-0.050}

Baryon fraction f_B = 0.220^{+0.058}_{-0.072}

Abstract

We use the final catalogue of the VIMOS Public Extragalactic Redshift Survey (VIPERS) to measure the power spectrum of the galaxy distribution at high redshift, presenting results that extend beyond $z=1$ for the first time. We apply an FFT technique to four independent sub-volumes comprising a total of $51,728$ galaxies at $0.6<z<1.1$ (out of the nearly $90,000$ included in the whole survey). We concentrate here on the shape of the direction-averaged power spectrum in redshift space, explaining the level of modelling of redshift-space anisotropies and the anisotropic survey window function that are needed to deduce this in a robust fashion. We then use covariance matrices derived from a large ensemble of mock datasets in order to fit the spectral data. The results are well matched by a standard $\Lambda$CDM model, with density parameter $\Omega_M h =\smash{0.227^{+0.063}_{-0.050}}$ and baryon fraction $\smash{f_B=\Omega_B/\Omega_M=0.220^{+0.058}_{-0.072}}$. These inferences from the high-$z$ galaxy distribution are consistent with results from local galaxy surveys, and also with the Cosmic Microwave Background. Thus the $\Lambda$CDM model gives a good match to cosmic structure at all redshifts so far accessible to observational study.