On the Hypermultiplet Moduli Space of Heterotic Compactifications with Small Instantons

We propose a method of computing the α corrections to the moduli space of hypermultiplets of N = 2 four-dimensional vacua resulting from compactifications of heterotic strings on K3 × T . The method is based on relating the hypermultiplet moduli space of the original model to the vector multiplet moduli space of the ”mirror” one which can be computed exactly due to Heterotic/Type II duality. We specifically consider the case of point-like instantons on orbifold singularities leading to a low-dimensional hypermultiplet moduli space. 1 [email protected]