Solutions and Democratic Formulation of Supergravity Theories in Four Dimensions

Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Física Teórica. Fecha de lectura: 15-06-0

Supersymmetric solutions of N=2 d=4 sugra: the whole ungauged shebang

In this article we complete the classification of the supersymmetric solutions of N=2 D=4 ungauged supergravity coupled to an arbitrary number of vector- and hypermultiplets. We find that in the timelike case the hypermultiplets cause the constant-time hypersurfaces to be curved and have su(2) holonomy identical to that of the hyperscalar manifold. The solutions have the same structure as without hypermultiplets but now depend on functions which are harmonic in the curved 3-dimensional space. We discuss an example obtained from a hyper-less solution via the c-map. In the null case we find that the hyperscalars can only depend on the null coordinate and the solutions are essentially those of the hyper-less case.Comment: 27 pages, latex2

The supersymmetric tensor hierarchy of N=1,d=4 supergravity

In this paper we construct the supersymmetric tensor hierarchy of N=1, d=4 supergravity. We find some differences with the general bosonic construction of 4-dimensional gauged supergravities. The global symmetry group of N=1,d=4 supergravity consists of three factors: the scalar manifold isometry group, the invariance group of the complex vector kinetic matrix and the U(1) R-symmetry group. In contrast to (half)-maximal supergravities, the latter two symmetries are not embedded into the isometry group of the scalar manifold. We identify some components of the embedding tensor with Fayet-Iliopoulos terms and we find that supersymmetry implies that the inclusion of R-symmetry as a factor of the global symmetry group requires a non-trivial extension of the standard p-form hierarchy. This extension involves additional 3- and 4-forms. One additional 3-form is dual to the superpotential (seen as a deformation of the simplest theory). We study the closure of the supersymmetry algebra on all the bosonic p-form fields of the hierarchy up to duality relations. In order to close the supersymmetry algebra without the use of duality relations one must construct the hierarchy in terms of supermultiplets. Such a construction requires fermionic duality relations among the hierarchy's fermions and these turn out to be local.Comment: Latex2e, 42 pages, no figures Improved version to be published in JEH

Domain walls and instantons in N=1, d=4 supergravity

We study the supersymmetric sources of (multi-) domain-wall and (multi-) instanton solutions of generic N=1, d=4 supergravities, that is: the worldvolume effective actions for said supersymmetric topological defects. The domain-wall solutions naturally couple to the two 3-forms recently found as part of the N=1, d=4 tensor hierarchy (i.e. they have two charges in general) and their tension is the absolute value of the superpotential section L. The introduction of sources (we study sources with finite and vanishing thickness) is equivalent to the introduction of local coupling constants and results in dramatic changes of the solutions. Our results call for a democratic reformulation of N=1,d=4 supergravity in which coupling constants are, off-shell, scalar fields. The effective actions for the instantons are always proportional to the coordinate orthogonal to the twist-free embedding of the null-geodesic (in the Wick-rotated scalar manifold) describing the instanton. We show their supersymmetry and find the associated supersymmetric (multi-) instanton solutions.Comment: 34 pages, 4 figures, references adde

Gauge Theories, Duality Relations and the Tensor Hierarchy

We compute the complete 3- and 4-dimensional tensor hierarchies, i.e. sets of p-form fields, with $1\le p\le D$, which realize an off-shell algebra of bosonic gauge transformations. We show how these tensor hierarchies can be put on-shell by introducing a set of duality relations, thereby introducing additional scalars and a metric tensor. These so-called duality hierarchies encode the equations of motion of the bosonic part of the most general gauged supergravity theories in those dimensions, including the (projected) scalar equations of motion. We construct gauge-invariant actions that include all the fields in the tensor hierarchies. We elucidate the relation between the gauge transformations of the p-form fields in the action and those of the same fields in the tensor hierarchy.Comment: 48 pages, v2: number of clarifications, ref. added, to appear in JHE

Stringy cosmic strings in matter coupled N=2, d=4 supergravity

We extend the system of ungauged N=2, d=4 supergravity coupled to vector multiplets and hypermultiplets with 2-form potentials. The maximal number of 2-form potentials that one may introduce is equal to the number of isometries of either the special Kaehler or quaternionic Kaehler sigma model. We show that the local supersymmetry algebra can be realized on the 2-form potentials. These 2-forms couple electrically to strings which we refer to as stringy cosmic strings. The 1/2 BPS bosonic world-sheet actions for these strings are constructed and we discuss the properties of the 1/2 BPS stringy cosmic string solutions.Comment: 36 pages, added references, corrected typos, modificated Appendix