HETEROTIC STRING VERTEX OPERATORS AND NEW MINIMAL SUPERGRAVITY

We apply the method of deformations of the stress-energy tensor to the case of the heterotic string compactified of d = 4 space-time preserving N = 1 supersymmetry. We construct a new vertex operator associated with an auxilliary antisymmetric background field in the supergravity sector and show that the construction is unique. We then obtain the supersymmetry transformations of the background fields and find them to be the same as those of the component fields of the new minimal supergravity multiplet and a physical linear multiplet coupled to a new minimal supergravity. We also show that it is possible to construct a vertex operator associated with an auxilliary scalar supergravity background field. We conclude that the heterotic string gives new minimal supergravity for any arbitrary compatification to four-dimensional space-time preserving N = 1 supersymmetry. © 1990.