Coset group realizations and space-time local symmetries

Abstract

We describe the general mathematical framework of the coset realizations of symmetry groups as a basis for the gauge theories. In this scheme the group characterization of the space-time coordinates is made apparent. As a result the general invariance and the standard space-time symmetries are naturally related. When the full conformal group is considered, the effective theory of the massless excitation of the closed bosonic string is found.