Coupled Λ N-Sigma N and Λ NN-Sigma NN systems and hyperon-nucleon interactions

This paper summarizes our studies of the hypertriton and describes our findings on the hyperon-nucleon interaction, especially on the role of the $\Lambda N-\Sigma N$ coupling and the strengths of the $S$-wave $YN$ interactions. We briefly comment on our ongoing analyses with electromagnetic probes.