GENERALIZED TODA THEORIES AND W-ALGEBRAS ASSOCIATED WITH INTEGRAL GRADINGS

A general class of conformal Toda theories associated with integral gradings of the simple Lie algebras is investigated. These generalized Toda theories are obtained by reducing the Wess-Zumino-Novikov-Witten (WZNW) theory by first class constraints, and thus they inherite extended conformal symmetry algebras, generalized W-algebras, and current dependent Kac-Moody (KM) symmetries from the WZNW theory, which are analysed in detail in a non-degenerate case. We uncover an sl(2) structure underlying the generalized W-algebras, which allows for identifying the primary fields, and give a simple algorithm for implementing the W-symmetries by current dependent KM transformations, which can be used to compute the action of the W-algebra on any quantity. We establish how the Lax pair of Toda theory arises in the WZNW framework and show that a recent result of Mansfield and Spence, which interprets the W-symmetry of the Toda theory by means of non-Abelian form preserving gauge transformations of the Lax pair, arises immediately as a consequence of the KM interpretation. © 1992.