Knizhnik-Zamolodchikov equations and spectral flow in AdS3 string theory

Abstract

I generalize the Knizhnik-Zamolodchikov equations to correlators of spectral flowed fields in AdS3 string theory. If spectral flow is preserved or violated by one unit, the resulting equations are equivalent to the KZ equations. If spectral flow is violated by two units or more, only some linear combinations of the KZ equations hold, but extra equations appear. Then I explicitly show how these correlators and the associated conformal blocks are related to Liouville theory correlators and conformal blocks with degenerate field insertions, where each unit of spectral flow violation removes one degenerate field. A similar relation to Liouville theory holds for noncompact parafermions.Comment: 21 pages, v2: "proof" section clarified and renamed "arguments", references adde