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G. L. Cardoso

Publications and source records attributed to G. L. Cardoso.

24 records · Page 2Linked to original sources

BPS Action and Superpotential for Heterotic String Compactifications with Fluxes

We consider N =1 compactifications to four dimensions of heterotic string theory in the presence of fluxes. We show that up to order O(α'^2) the associated action can be written as a sum of squares of BPS-like quantities. In this way we prove that the equations of motion are solved by backgrounds which fulfill the supersymmetry conditions and the Bianchi identities. We also argue for the expression of the related superpotential and discuss the radial modulus stabilization for a class of examples.

hep-th↗

Non-Kaehler String Backgrounds and their Five Torsion Classes

We discuss the mathematical properties of six--dimensional non--Kähler manifolds which occur in the context of ${\cal N}=1$ supersymmetric heterotic and type IIA string compactifications with non--vanishing background H--field. The intrinsic torsion of the associated SU(3) structures falls into five different classes. For heterotic compactifications we present an explicit dictionary between the supersymmetry conditions and these five torsion classes. We show that the non--Ricci flat Iwasawa manifold solves the supersymmetry conditions with non--zero H--field, so that it is a consistent heterotic supersymmetric groundstate.

hep-th↗

Stationary BPS Solutions in N=2 Supergravity with R^2-Interactions

We analyze a broad class of stationary solutions with residual N=1 supersymmetry of four-dimensional N=2 supergravity theories with terms quadratic in the Weyl tensor. These terms are encoded in a holomorphic function, which determines the most relevant part of the action and which plays a central role in our analysis. The solutions include extremal black holes and rotating field configurations, and may have multiple centers. We prove that they are expressed in terms of harmonic functions associated with the electric and magnetic charges carried by the solutions by a proper generalization of the so-called stabilization equations. Electric/magnetic duality is manifest throughout the analysis. We also prove that spacetimes with unbroken supersymmetry are fully determined by electric and magnetic charges. This result establishes the so-called fixed-point behavior according to which the moduli fields must flow towards certain prescribed values on a fully supersymmetric horizon, but now in a more general context with higher-order curvature interactions. We briefly comment on the implications of our results for the metric on the moduli space of extremal black hole solutions.

hep-th↗

Supersymmetric black hole solutions with $R^2$-interactions

We present a class of static supersymmetric multi-center black hole solutions arising in four-dimensional N=2 supergravity theories with terms quadratic in the Weyl tensor. We also comment on possible corrections to the metric on the moduli space of these black holes solutions.

hep-th↗