2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/206706For Hitchin's generalised geometries we introduce and analyse the concept of a structured submanifold which encapsulates the classical notion of a calibrated submanifold. Under a suitable integrability condition on the ambient geometry, these generalised calibrated cycles minimise a functional occurring as D-brane energy in type II string theories, involving both so-called NS-NS- and R-R-fields. Further, we investigate the behaviour of calibrated cycles under T-duality and construct non-trivial examples.43 pages. v4: formalism and T-duality part considerably expandedDifferential GeometryHigh Energy Physics - Theory53C38, 53C10, 53C27, 81T30, 83E50text