Non-local charges, Zm gradings and coset space actions

TL;DR

This paper generalizes the construction of flat currents and non-local charges for superstrings on AdS_5 x S^5, extending to all coset spaces with a Zm grading structure, and identifies the unique Wess-Zumino term needed.

Contribution

It demonstrates the existence of flat currents for sigma-model actions on coset spaces with Zm gradings, generalizing previous superstring models.

Findings

Existence of flat currents for all coset spaces with Zm grading.

Identification of a unique Wess-Zumino term compatible with the grading.

Extension of non-local charge construction to broader classes of models.

Abstract

The construction of flat currents, and hence conserved non-local charges, for the superstring on AdS_5 x S^5 is generalised. It is shown that such currents exist for sigma-model type actions on all coset (super-)spaces G/H in which, at the level of the Lie algebras, h is the grade-zero subspace of a Zm grading of g. This is true for an essentially unique choice of the Wess-Zumino term, which is determined.