Study of type IIB superstrings on curved backgrounds.

摘要

We study the Type IIB superstring theory on flat and curved backgrounds using three different covariant worldsheet formalisms. We start by considering the Type IIB Superstrings on flat space using the U(5) formulation developed by Nathan Berkovits [1]. We calculate an explicit representation for the manifest symmetry generators and display the invariance of the action under the transformations produced by them. Next, we use the covariant pure spinor formulation [2, 3, 4, 5, 6, 7, 8, 9, 10] to calculate the scattering amplitudes for three gravitons, and two axions with one graviton on the flat background. We also compute the scattering amplitude for two axions with one graviton on the AdS₅ × S₅ background. To the best of our knowledge, this is the only string correlation function calculation on AdS₅ × S₅. Finally, we use the $N$ = (2,2) superconformal U(4) formalism[11] to calculate a world-sheet representation for the U(4) generators together with sixteen fermionic generators, which are the part of the isometry group for the plane wave background limit of AdS₅ × S₅ .