Preference for evolving dark energy in light of the galaxy bispectrum

par Théo SIMON (Montpellier Universe and Particles Laboratory - CNRS)

mardi 6 mai 2025, 14:00 → 16:00 Europe/Paris

In this talk, I will first present the paradigm of the effective field theory of large-scale structure (EFTofLSS), a semi-analytical method which provides an accurate description of the power spectrum and bispectrum of bias tracers, and aims at improving cosmological constraints from large-scale structure surveys, a major challenge in the context of DESI and the forthcoming Euclid mission. Second, I will present our results obtained in arXiv:2503.04602, where we constrain the dark energy equation of state parametrized by (w0, wa) through an EFTofLSS bispectrum analysis applied to SDSS data. Using pre-DESI clustering data, combined with CMB data from Planck and supernova data from Pantheon+, Union3, or DESY5, we find a 2.8 − 3.9 sigma preference for evolving dark energy over the cosmological constant Λ. This preference appears only when we include the one-loop bispectrum, demonstrating the importance of this contribution to constraining the dark energy history. Finally, our findings are interpreted within the Effective Field Theory of Dark Energy (EFTofDE), considering the clustering quintessence limit and the smooth quintessence limit.

 

Video record