Towards a unified description of the four interactions in terms of Dirac-Bergmann observables

Abstract

A review is given of the status and developments of the research program aiming to reformulate the physics of the four interactions at the classical level in a unified way in terms of Dirac-Bergmann observables with special emphasis on the open mathematical, physical and interpretational problems.

Comments: 40 pages, revtex file, Invited contribution to the book of the Indian National Science Academy for the International Mathematics Year 2000 ad