Heterotic String Corrections from the Dual Type II String

Abstract

We introduce a method of using the a dual type IIA string to compute alpha'-corrections to the moduli space of heterotic string compactifications. In particular we study the hypermultiplet moduli space of a heterotic string on a K3 surface. One application of this machinery shows that type IIB strings compactified on a Calabi-Yau space suffer from worldsheet instantons, spacetime instantons and, in addition, "mixed" instantons which in a sense are both worldsheet and spacetime. As another application we look at the hyperkaehler limit of the moduli space in which the K3 surface becomes an ALE space. This is a variant of the "geometric engineering" method used for vector multiplet moduli space and should be applicable to a wide range of examples. In particular we reproduce Sen and Witten's result for the heterotic string on an A1 singularity and a trivial bundle and generalize this to a collection of E8 point-like instantons on an ALE space.

21 pages, 5 figures, refs added

Cited by in corpus (6)

• Instantons, Hypermultiplets and the Heterotic String
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• A new vista on the Heterotic Moduli Space from Six and Three Dimensions
• N=2 Heterotic-Type II duality and bundle moduli
• Heterotic-type II duality in twistor space
• Heterotic-Type II duality in the hypermultiplet sector