A BRST lagrangian quantization of reducible gauge theories: Non-abelianp-forms and string field theories

By a suitable deformation of the reducible BRST algebra of the Abelian p-forms we obtain an explicit nilpotent BRST for the corresponding open reducible non-Abelianp-forms theory. We consider the Freedman-Townsend model and the corresponding (topological) massless limit. This allows us to perform a standard BRST quantization of the theory which avoids the Batalin-Vilkovisky formalism. This procedure leads to the introduction of auxiliary fields (related to BV antifields) which assume a universal form in terms of a single object belonging to the universal enveloping algebra. The auxiliary fields are interpreted as a sort of connection. A formal extension to the case of string field theory is presented.