Nelson, Philip C2023-05-232023-05-231989-04-012017-04-14https://repository.upenn.edu/handle/20.500.14332/43309This letter points a close parallel between the operator formalism for string theory and the action of a Lie algebra on a differential complex. The construction of conformal field theories can then be regarded as a cohomology problem; we suggest that this viewpoint may survive the generalization beyond finite genus Riemann surfaces.Physical Sciences and MathematicsPhysicsArticle