Zhu's Theorem and an algebraic characterization of conformal blocks

Working in the axiomatic framework recently proposed by Gaberdiel and Goddard, we prove a generalized version of Zhu's Theorem; for any chiral bosonic conformal field theory on the sphere, our result characterizes the chiral blocks in terms of a certain quotient of the Fock space. We also establish, under a finiteness hypothesis closely related to rationality of the theory, that the relevant Knizhnik-Zamolodchikov-type equation admits solutions.