§16§§This book presents theoretical methods and experimental results on the study of multipartite quantum correlations in spin-squeezed Bose-Einstein condensates. Nonclassical correlations in many-body systems are particularly interesting for both fundamental research and practical applications. For their investigation, ultracold atomic ensembles offer an ideal platform, due to their high controllability and long coherence times. In particular, we introduce criteria for detecting and characterizing multipartite entanglement, Einstein-Podolsky-Rosen steering, and Bell correlations. Moreover, we present the experimental observation of such correlations in systems of about 600 atoms.§ § §04§§Introduction.- Bose-Einstein condensates: Theory.- Bose-Einstein condensates: Experiments.- Quantum correlations: Theory.- Quantum correlations: Experiments.- Summary and outlook.§ §02§§Matteo Fadel studied physics at the University of Padova (Italy) and at ETH Zurich (Switzerland). He obtained a PhD from the University of Basel, where he investigated both theoretically and experimentally quantum correlations in many-body systems. Among other awards, Dr. Fadel won the Prix Schläfli of the Swiss National Science Foundation and the SPS prize of the Swiss Physical Society.§ §
