VIRASORO ALGEBRA IN THE KN ALGEBRA: BOSONIC STRING WITH FERMIONIC GHOSTS ON RIEMANN SURFACES

The bosonic string model with fermionic ghosts is considered in the framework of the KN algebra. Our attentions are paid to representations of KN algebra and a Clifford algebra of the ghosts. We show that a Virasoro-like algebra is obtained from KN algebra when KN algebra has certain antilinear anti-involution, and that it is isomorphic to the usual Virasoro algebra. We show that there is an expected relation between a central charge of this Virasoro-like algebra and an anomaly of the combined system.