We derive necessary and sufficient conditions for N = 1 compactifications of (massive) IIA supergravity to AdS4 in the language of SU(3) structures. We find new solutions characterized by constant… (More)

We calculate various tree–level (disk) scattering amplitudes involving gauge, matter and moduli fields in type IIB toroidal orbifold/orientifold backgrounds with D9, D5 respectively D7, D3–branes or… (More)

This review article provides a pedagogical introduction into various classes of chiral string compactifications to four dimensions with D-branes and fluxes. The main concern is to provide all… (More)

We construct sixand four-dimensional toroidal compactifications of the Type I string with magnetic flux on the D-branes. The open strings in this background probe a noncommutative internal geometry.… (More)

We study brane realizations of chiral matter in N = 1 supersymmetric gauge theories in four dimensions. A “cross” configuration which leads to “flavor doubling” is found to have a superpotential. The… (More)

We rewrite the recently derived cubic action of Double Field Theory on group manifolds [1] in terms of a generalized metric and extrapolate it to all orders in the fields. For the resulting action,… (More)

We discuss general bosonic stationary configurations of N = 2, D = 4 supergravity coupled to vector multiplets. The requirement of unbroken supersymmetries imposes constraints on the holomorphic… (More)

We discuss supersymmetry breaking via 3–form fluxes in chiral supersymmetric type IIB orientifold vacua withD3– and D7–branes. After a general discussion of possible choices of fluxes allowing for… (More)

We use heterotic/type-II prepotentials to study quantum/classical black holes with half the N = 2, D = 4 supersymmetries unbroken. We show that, in the case of heterotic string compactifications, the… (More)

We analyze the perturbative stability of non-supersymmetric intersecting brane world models on tori. Besides the dilaton tadpole, a dynamical instability in the complex structure moduli space occurs… (More)