Duality Invariant Superstring Actions

TL;DR

This paper develops a duality invariant formulation of worldsheet supersymmetric string actions in both flat and curved backgrounds, introducing auxiliary fields and superfield forms to preserve duality symmetry.

Contribution

It presents a novel duality invariant superstring action framework, including auxiliary fields and superfield formulations, extending to curved backgrounds with independent metric and torsion fields.

Findings

Duality invariant flat background action with auxiliary fields

Superfield form and offshell supersymmetry algebra derived

Duality invariant curved background sigma model formulated

Abstract

Worldsheet supersymmetric string action is written in duality invariant form for flat as well as curved backgrounds. First the action in flat backgrounds is written by introducing auxiliary fields. We also give the superfield form of this action and obtain the offshell supersymmetry algebra. The action has a modified Lorentz invariance and supersymmetry and reduces to the usual form when the auxiliary fields are eliminated using their equations of motion. Supersymmetric nonlinear sigma model in curved backgrounds is also written in manifestly duality invariant form when the background metric and tortion fields are independent of some of the coordinates.