26-126 Euclid Weak-Lensing Cluster Cosmology Inference

Mission

Context

Formed hierarchically from the collapse of initial density fluctuations, the evolution of galaxy clusters over time reflects the underlying cosmology of the Universe. The measurement of their abundance, the number of clusters as a function of mass and redshift, can provide constraints on dark energy and structure growth Ghirardini et al. 2024, Artis et al. 2025)

Up to now, cosmological constraints from cluster abundance rely on cluster detection through their baryonic signal through the intracluster gas content in X-rays, using the Sunyaev-Zeldovich effect at millimetre wavelengths, or through the optical light in the galaxies). However, the baryonic selection is known to suffer from several biases, primarily linked to feedback processes within the cluster galaxies. 

In this project, we propose to follow the pioneering work of Chiu I-N. et al 2024 on Hyper SuprimeCam data that derived first cosmological constraints based on 12...