Orateur
Description
To test the consistency of the flat ΛCDM model, we perform a multi-messenger parameter split of the present-day matter density Ω_m into three different regimes. The first regime concerns the geometrical expansion and thus cosmological distances. The second regime is based on the formation and growth of structures in the universe due to gravitational instabilities. As an extension to earlier studies, we also consider a third regime which concerns the early universe before recombination. This allows for a separate evolution of the matter density in every regime.
In this talk, I will present a joint analysis combining weak lensing and galaxy clustering (3x2pt) data from the Dark Energy Survey (DES), cosmic microwave background (CMB) data from Planck, Supernovae Type Ia (SNIa) data from Pantheon+ without cepheid calibration and redshift space distortions (RSD) from a combination of spectroscopic surveys.
In our preliminary results, we find a strong correlation between Ω_m in the early and in the geometric regime. However, both of these have a mild tension with the growth regime, 2.3σ between the early and the growth Ω_m and 2.2σ between the geometry and the growth Ω_m.
