On the NSR formulation of string theory on AdS5×S

We discuss the NSR formulation of the superstring action on AdS₅×S⁵ proposed recently by Kallosh and Tseytlin in the Green-Schwarz formalism. We show that the stress-energy tensor corresponding to the NSR action for AdS superstring contains the branelike terms, corresponding to exotic massless vertex operators (referred to as the branelike vertices)- the 5-form e^φψ_m1ψ_m5 and the 3-form ∂(e^φψ_m1ψ_m3), multiplied by ∂X_m. The corresponding sigma-model action has the manifest SO(1,3)×SO(6) invariance of superstring theory on AdS₅×S⁵. We argue that adding the branelike terms is equivalent to curving the space-time to obtain the AdS₅×S⁵ background. We commence the study of the proposed NSR sigma-model by analyzing the scattering amplitudes involving the branelike vertex operators. The analysis shows quite an unusual momentum dependence of these scattering amplitudes.