Interacting dark energy constraints from the full-shape analyses of BOSS DR12 and DES Year 3 measurements
M. Tsedrik, Sang Hyun Lee, K. Markovič, P. Carrilho, A. Pourtsidou, Chiara Moretti, Benjamin Bose, Emily S. Huff, A Robertson, P.L. Taylor, J. Zuntz
Abstract
ABSTRACT Dark scattering (DS) is an interacting dark energy model characterized by pure momentum exchange between dark energy and dark matter. It is phenomenologically interesting because it is unconstrained by CMB data and can alleviate the $S_8$ tension. We derive constraints on cosmological and DS parameters using three two-point correlation functions from the Dark Energy Survey third year data release (DES Y3). We then add information from the multipoles of the galaxy power spectrum combined with BAO measurements using the twelfth data release of the Baryon Oscillation Spectroscopic Survey (BOSS DR12) and external BAO measurements. We compare results from the direct combination of the probes with the joint posterior distribution calculated with a normalizing flow approach. Additionally, we run a CMB analysis with the Planck Public Release 4 (PR4) for comparison of the cosmological constraints. Overall, we find that the combination of probes allows minimizing projection effects and improves constraints without the need to include CMB information. It brings the marginalized posterior maxima closer to the corresponding best-fitting values and weakens the sensitivity to the priors of the spectroscopic modelling nuisance parameters. These findings are highly relevant in light of forthcoming data of surveys like DESI, Euclid, and Rubin.