BOSS full-shape analysis from the EFTofLSS with exact time dependence

TL;DR

This paper refines the analysis of BOSS galaxy data using the Effective-Field Theory of Large-Scale Structure, removing common approximations to improve cosmological parameter constraints and assess systematic effects.

Contribution

It introduces an exact time dependence in the EFT analysis of galaxy clustering, removing the EdS approximation and properly accounting for redshift selection, leading to more accurate cosmological constraints.

Findings

No significant shift due to EdS approximation.

Marginal difference in primordial amplitude from redshift approximation.

Constraints on cosmological parameters consistent with previous analyses.

Abstract

We re-analyze the full shape of BOSS galaxy two-point function from the Effective-Field Theory of Large-Scale Structure at the one loop within $\Lambda$CDM with massive neutrinos using a big bang nucleosynthesis (BBN) prior, removing the Einstein-de Sitter (EdS) approximation in the time dependence of the loop, and, properly accounting for the redshift selection over the BOSS samples instead of assuming an effective redshift. We constrain, at $68\%$-confidence level (CL), the present-day matter fraction to $\Omega_m=0.322 \pm 0.018$, the Hubble constant to $H_0=69.1\pm 0.14$ (km/s)/Mpc, the $\log$-amplitude of the primordial spectrum to $\ln (10^{10} A_s) = 2.97 \pm 0.25$, the spectral tilt to $n_s = 0.938 \pm 0.082$, and bound the total neutrino mass to $<1.1$ at $95\%$-CL. We find no significant shift in the posteriors of the cosmological parameters due to the EdS approximation, but a marginal difference in $\ln (10^{10} A_s)$ due to the effective redshift approximation of about $0.4\sigma$, where $\sigma$ is the $68\%$-confidence interval. Regarding the EdS approximation, we check that the same conclusion holds on simulations of volume like DESI in $\Lambda$CDM and $w$CDM, with a BBN prior. In contrast, for an approximate, effective redshift, to be assumed, we advocate systematic assessments on redshift selection for ongoing and future large-volume surveys.