Generalized Supergravity Equations and Generalized Fradkin-Tseytlin Counterterm

Understand

The generalized Fradkin-Tseytlin counterterm for the (type I) Green-Schwarz superstring is determined for background fields satisfying the generalized supergravity equations (GSE).

• For this purpose, we revisit the derivation of the GSE based upon the requirement of kappa-symmetry of the superstring action.
• Lifting the constraint of vanishing bosonic torsion components, we are able to make contact to several different torsion constraints used in the literature.
• It is argued that a natural geometric interpretation of the GSE vector field that generalizes the dilaton is as the torsion vector, which can combine with the dilatino spinor into the torsion supervector.