Three- and four-body structure of light hypernuclei

Two important goals of hypernuclear physics are to investigate the hyperon-nucleon(YN) and hyperon-hyperin(YY) interactions and (2) to discover novel dynamical nuclear structure effects induced by the hyepron such as $\Lambda$, $\Sigma$, $\Xi$ and so on. At the Jeffereson Laboratory and J-PARC, they planning to produce many single hypernuclei and double $\Lambda$ hypernuclei. Here we discuss about 1) YN spin-orbit force and the structure of $^9_{\Lambda}$Be and $^{13}_{\Lambda}$C, 2) YN spin-spin force and the structure of $^7_{\Lambda}$Li, 3) $\Lambda N-\Sigma N$ coupling and the structure of $^4_ {\Lambda}$He and $^7_{\Lambda}$He, and 4)$\Lambda -\Lambda$ interaction and structure of light p- shell double $\Lambda$ hypernuclei. We also emphasis what is interesting and important from the view point of hypernuclear physics.