Massive images and heterotic five-branes on K3 Original Research Article

We systematically consider heterotic image and image compactifications on K3 with Abelian and non-Abelian backgrounds as well as an arbitrary number of five-branes. The masses of the image factors depend on the first Chern classes of the bundles and some combinatorial factors specifying the embedding in image or image. The form of the generalised Green–Schwarz counter-terms in six dimensions constrains the possible heterotic five-brane actions. Some supersymmetric examples on K3 realisations as toric complete intersection spaces with up to three explicit two-forms are given.