Self-Dual N=8 Supergravity as Closed N=2(4) Strings

TL;DR

This paper explores how certain open and closed string theories in 2+2 dimensions relate to self-dual super Yang-Mills and supergravity, emphasizing their formulation in chiral superspace and gauge invariances.

Contribution

It provides a formulation of self-dual N=8 supergravity as a closed N=2(4) string theory using chiral superspace and analyzes its super-light-cone and covariant actions.

Findings

Closed heterotic strings describe self-dual N=8 supergravity.

Supergravity equations reduce to vanishing torsion due to partial Lorentz gauging.

Chiral superspace formulation simplifies the analysis of these theories.

Abstract

As open N=2 or 4 strings describe self-dual N=4 super Yang-Mills in 2+2 dimensions, the corresponding closed (heterotic) strings describe self-dual ungauged (gauged) N=8 supergravity. These theories are conveniently formulated in a chiral superspace with general supercoordinate and local OSp(8|2) gauge invariances. The super-light-cone and covariant-component actions are analyzed. Because only half the Lorentz group is gauged, the gravity field equation is just the vanishing of the torsion.