Recent developments in supergravity theories

It is commonly accepted that any scheme of unification of the fundamental interactions should lead to N = 1 Supergravity in four dimensions as an intermediate step. As such, N = 1 Supergravity should represent a low energy effective theory, emerging from a more general theory, which provides a consistent, quantum framework where the arbitrariness of the matter coupling of the N = 1 theory is removed. The guiding principles for such a scheme are essentially based on Extended Supergravity and/or Kaluza-Klein theories and on the much more promising Superstring theory