1,721,039 research outputs found
Electrified branes
A geometrical form of the supersymmetry conditions for D-branes on arbitrary type II supersymmetric backgrounds is derived, as well as the associated BPS bounds. The treatment is general and allows to consider, for instance, non-static configurations or D-branes supporting a non-vanishing electric flux, hence completing previous partial results. In particular, our discussion clarifies how the notion of calibration can be extended in order to be applicable to the most general supersymmetric configurations. As an exemplifying preliminary step, the procedure followed is first applied to fundamental strings
On moduli and effective theory of N= 1 warped flux compactifications
The moduli space of N = 1 type II warped compactions to flat space with generic internal fluxes is studied. Using the underlying integrable generalized complex structure that characterizes these vacua, the different deformations are classified by H-twisted generalized cohomologies and identified with chiral and linear multiplets of the effective four-dimensional theory. The Kähler potential for chiral fields corresponding to classically flat moduli is discussed. As an application of the general results, type IIB warped Calabi-Yau compactifications and other SU(3)-structure subcases are considered in more detail. © 2009 SISSA
Topological duality twist and brane instantons in F-theory
A variant of the topological twist, involving SL(2, Z) dualities and hence named topological duality twist, is introduced and explicitly applied to describe a U(1) N = 4 super Yang-Mills theory on a Kähler space with holomorphically space-dependent coupling. Three-dimensional duality walls and two-dimensional chiral theories naturally enter the formulation of the duality twisted theory. Appropriately generalized, this theory is relevant for the study of Euclidean D3-brane instantons in F-theory compactifications. Some of its properties and implications are discussed
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