Inflow di Anomalia in teorie di stringa non supersimmetriche

In this Thesis we explore the consistency of perturbative string theories where space-time supersymmetry is either absent or broken at the string scale. To this end we study the cancellation of gauge anomalies in a number of orientifold models, where the Green-Schwarz mechanism plays a crucial role. We focus on anomaly cancellation on the world volume of D-branes via inflow from the bulk, completing the results of Dudas, Mourad and Sagnotti. Concretely, we verify this type of anomaly cancellation in the Sugimoto model, the remaining case among the tachyon-free non-supersymmetric string theories in ten dimensions.