Simple current extensions of tensor products of vertex operator algebras
arXiv:1804.08242
Abstract
We study simple current extensions of tensor products of two vertex operator algebras satisfying certain conditions. We establish the relationship between the fusion rule for the simple current extension and the fusion rule for a tensor factor. In a special case, we construct a chain of simple current extensions. We discuss certain irreducible twisted modules for the simple current extension as well.
20 pages; an assumption is removed; some materials are deleted