Cosmological constraints from combined probes with the three-point statistics of galaxies at one-loop precision

Abstract

We present cosmological constraints from a joint analysis including the power spectrum and bispectrum of BOSS galaxies based on the Effective Field Theory of Large-Scale Structure predictions at one-loop order, in combination with CMB data from Planck, Supernovae from Pantheon+, and BAO from eBOSS and 6dF/MGS. Limits on $\Lambda$CDM parameters are in good agreement, and on average $\sim 5-10\%$ tighter, compared to former results including similar datasets but no bispectrum. Moreover, we find that galaxies at the three-point level with one-loop precision are decisive for the dark energy equation of state, constrained to be $w =-0.975 \pm 0.019$ at $68\%$CL. This value, consistent at $\sim 1.3\sigma$ with a cosmological constant, represents an improvement of about $140\%$ with respect to former determination. Our analyses illustrate the importance of beyond-two-point statistics at the highest reachable scales in constraining cosmological parameters, and in particular departure from $\Lambda$CDM.