Superstrings on AdS_5 x S^5 supertwistor space

TL;DR

The paper introduces an alternative coset construction to derive the Green-Schwarz action for strings on AdS5×S5 by reformulating the coset as GL(4|4)/(Sp(4)×GL(1))^2, enabling unconstrained matrices and a manifestly conformal framework. It develops both bosonic and full supercoset actions, proves κ-symmetry, and provides transparent gauge-fixing options, including a Kallosh-Rahmfeld-Pesando gauge and a complex gauge that yield simpler, though non-hermitian, forms. The flat-space limit is obtained explicitly, recovering the standard GS action in a chiral supersymmetry basis. The approach promises a streamlined path to understanding the associated conformal field theory and may extend to other AdS×S backgrounds, with implications for exact worldsheet descriptions in RR backgrounds.

Abstract

We derive the Green-Schwarz action on AdS_5 x S^5 using an alternate version of the coset superspace construction. By Wick rotations and Lie algebra identifications we bring the coset to GL(4|4)/(Sp(4) x GL(1))^2, which allows us to represent the conformal transformations on unconstrained matrices. The derivation is more streamlined even for the bosonic sector, and conformal symmetry is manifest at every step. Kappa-symmetry gauge fixing is more transparent.