Aim: The goal of this work package is to derive an accurate model to describe the relation between the AMICO mass proxies, the cluster lensing shear profile and the underlying halo mass, which is effective over the whole mass range probed by the cosmological catalog. This corresponds to characterize the probability distribution P(O|M,z), which encodes the scaling relation and survey selection function. Of paramount importance are: i) the modeling of the tails of the distribution, which controls the purity and completeness of the sample, and ii) the modeling of the correlations between mass proxies and weak lensing signal, which if not properly addressed leads to biases in the cluster mass estimates, and thus in the inferred cosmological parameters.

Along with the characterization of the model we aim at identifying and developing computational techniques which allow a fast and accurate derivation of the theoretical quantities required for the likelihood evaluation.

Related Publications:

Fumagalli et al. (2025) – Euclid: Exploring observational systematics in cluster cosmology — a comprehensive analysis of cluster counts and clustering.

This paper presents a systematic study of observational systematics affecting cluster number counts and clustering statistics in Euclid-like surveys, providing validated modelling tools and covariance estimates for cosmological analyses.

Grandis et al. (2025) – Selection function of clusters in Dark Energy Survey year 3 data from cross-matching with South Pole Telescope detections.

This work develops and applies a method to empirically determine the selection function of optically selected clusters through cross-matching with SZ-selected samples. The methodology was successfully applied to the optical cluster catalog derived from Dark Energy Survey Y3 data, and SZ detections of the South Pole Telescope surveys (SPT-SZ, SPTpol-ECS, and SPTpol-500d) .

Lee et al. (2025) – Optical galaxy cluster mock catalogs with realistic projection effects: validations with the SDSS clusters.

This study presents simulated optical cluster catalogs that incorporate realistic projection effects and validates them against observational SDSS data. This analysis provides an essential component for producing a realistic mock cluster catalogs, and thus testing cluster-finding algorithms and calibrating optical cluster systematics.

Costanzi et al. (submitted to PRD) – A forward analytical model for the optical selection bias on galaxy cluster lensing profiles.

This work develops a physical analytical model describing the impact of optical selection effects and projection biases on cluster weak-lensing measurements, enabling a consistent modelling of correlated scatter between optical richness and lensing observables directly linked to the underlying cosmology and survey specifications.

Ingrao et al. (in preparation) – CosmoPostProcess: a simulation-calibrated framework for weak-lensing selection bias in richness-selected galaxy clusters.

This paper presents the CosmoPostProcess pipeline developed within EMC2 to generate Euclid-like cluster catalogs from simulations and to calibrate selection biases affecting cluster lensing measurements.