Ten-dimensional heterotic strings from Niemeier lattices

Abstract

It is shown how all known ten-dimensional heterotic string theories with rank-16 gauge groups can be derived in a direct way from Niemeiers classification of euclidean even self-dual lattices in 24 dimensions. This result is based on a recent construction of heterotic strings from odd self-dual lorentzian lattices. A natural embedding of all these theories in the 26-dimensional closed basonic string is suggested by this construction.