On the strong coupling behavior of heterotic and type I orbifolds
arXiv:hep-th/0005124 · doi:10.1088/1126-6708/2001/03/024
Abstract
We study the bulk effective theory of a class of orbifolds of the type IIB string with D5-branes, compactified to four dimensions. These constructions are connected, in a region of their moduli space, to some orbifolds of the type I and heterotic string. We compare the effective actions through the coupling of the R^2 term, and we argue that these orbifolds provide non-perturbative deformations of the latter, in which the gauge group is entirely non-perturbative.
17 pages, latex, revised version with some rewriting and new comments added