The cosmological analysis of DES 3$\times$2pt data from the Effective Field Theory of Large-Scale Structure

TL;DR

This paper applies the Effective Field Theory of Large-Scale Structure to analyze DES Year 3 data, measuring cosmological parameters with validated methods and comparing results with other major surveys, highlighting modeling impacts.

Contribution

It introduces a pipeline using EFTofLSS for 3x2pt analysis of DES data, validated against simulations, and provides publicly available code for the community.

Findings

Measured $S_8=0.833\u00b10.032$

Found $\u03a9_m=0.272\u00b10.022$

Results consistent with Planck and BOSS analyses

Abstract

We analyze the Dark Energy Survey (DES) Year 3 data using predictions from the Effective Field Theory of Large-Scale Structure (EFTofLSS). Specifically, we fit three two-point observables (3$\times$2pt), galaxy clustering, galaxy-galaxy lensing, and cosmic shear, using the one-loop expressions for the projected angular correlation functions. We validate our pipeline against numerical simulations and we check for several internal consistencies before applying it to the observational data. Fixing the spectral tilt and the baryons abundance, we measure $S_8=0.833\pm 0.032$, $\Omega_m = 0.272\pm 0.022$, and $h = 0.773\pm 0.049$, to about $3.8\%$, $8.1\%$, and $6.3\%$, at $68\%$CL, respectively. Our results are consistent at the $\sim 1.5-2\sigma$ level with those from Planck and the BOSS full-shape analyses, as well as with those from DES collaboration 3$\times$2pt analysis combined with a Big-Bang Nucleosynthesis prior and a Planck prior on $n_s$. The shift in the posterior compared to DES collaboration results highlights the impact of modeling, scale cuts, and choice of prior. The theory code and likelihood used for our analyses, \texttt{PyFowl}, is made publicly available.