Update on the crisis in nuclear-matter theory: a summary of the Trieste conference

The turbulent recent history of the nulcear-matter problem, involving large discrepancies between Brueckner-Bethe and variational calculations, is sketched, and the conference is reviewed with the resolution of these discrepancies as an underlying theme. The development and testing of advanced variational methods are recounted, and the extension of these methods to realistic treatment of realistic problems such as liquid 4He, liquid 3He and the electron gas is described. Some new opportunities for variational theory are indicated. The calculational schemes for handling state-dependent correlations in nuclear matter are discussed, and the current status of the nuclear saturation problem is assessed. (Auth.)