LOcal Clusters And supercLuster In sZ: Adding Thermal, kInetic and relativistic cOrrectioNs
Despite the great success of the numerous analyses opening on to the precision cosmology era that led to the establishment of the ΛCDM model as the standard model, our understanding of the Universe is shaken by several anomalies and tensions. These tensions point at differences between the linearly evolved amplitude of the matter power σ8, measured with the CMB or derived with lensing or clusters of galaxies (the so-called σ8 tension). In addition, CMB large-scale anomalies (e.g. low quadrupole moment, quadrupole/octupole alignment, north/south asymmetry, etc.) have also been highlighted. While these anomalies and tensions could be smoking guns of departures from the pillars of the cosmological principle, namely homogeneity or isotropy, or indications of an urgent need to turn to non-standard physics (such as Quintessence, K-essence, coupled dark-energy, modified gravity, loop quantum cosmology, etc.), they might also all be attributed to more standard causes such as systematic effects or to intrinsic limitations in the modeling of the cosmological probes. They hence deserve special attention.
LOCALIZATION project is designed to search, in the local matter distribution, for a common answer to both the σ8 tension and the CMB anomalies observed in the Planck data, by performing a comprehensive analysis of local galaxy clusters and Large-Scale Structure (LSS) and of their impact on the CMB. Replicas of the local clusters and LSS will be produced in unique state-of-the-art constrained hydrodynamic simulations, namely high fidelity clones of the local Universe within roughly 300 Mpc radius valid down to cluster scales. We will address the σ8 tension focusing on the intrinsic limitation that afflicts the cosmological constraints from clusters, namely the mass scaling relation. We will address the CMB anomalies in Planck data focusing on sources of CMB signal that contribute at the largest angular scales, namely those attributed to the local supercluster and clusters.