General aspects of heterotic string compactifications on stacks and gerbes

摘要: In this paper we work out some basic results concerning heterotic string compactifications on stacks and, in particular, gerbes. A compactification a gerbe can be understood as, simultaneously, both space with restriction nonperturbative sectors, and also, gauge theory which subgroup of the group acts trivially massless matter. Gerbes admit more bundles than corresponding spaces, suggests they are potentially rich playground for compactifications. After give general characterization strings stacks, specialize to gerbes, consider three different classes ‘building blocks’ We argue that one class is equivalent same disjoint union another dual other third not perturbatively consistent, so do fact recover broad array new compactifications, just combinations existing ones. appendices explain how compute spectra derive necessary conditions stack or orbifold well-defined, also review properties