Type IIB orbifolds with D5-branes and their string duals Original Research Article

We consider Z2 , freely acting orbifolds of the type IIB string with 16 parallel D5-branes. When the string is compactified on T2×T4 and the D5-branes are wrapped on T2 , these systems possess N4=2 supersymmetry, originating from the spontaneous, partial breaking of N4=4 . Extended supersymmetry allows us to investigate the duality with certain heterotic and type I constructions, and to obtain information about their non-perturbative regime.