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Supergravity Theories (supergravity + theory)

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Physics and Astronomy100%

Selected Abstracts

Is N = 8 supergravity a finite field theory?

FORTSCHRITTE DER PHYSIK/PROGRESS OF PHYSICS, Issue 5-7 2009
Article first published online: 21 APR 200, K.S. Stelle
Abstract Advances in calculational technique permit the study of ultraviolet structure in maximal super Yang-Mills and maximal supergravity theories at heretofore unattainable loop orders. Hints from string theory suggest that maximal supergravity might have a similar ultraviolet behavior in D = 4 spacetime dimensions as maximal super Yang-Mills theory and so be ultraviolet convergent. Yet what is known of field theoretic nonrenormalization theorems suggests only that -BPS counterterms are excluded. A key test of the relative finiteness properties of the two theories will be the ultraviolet divergences in D = 5 maximal supergravity at the four-loop level. [source]

Constraints from F and D supersymmetry breaking in general supergravity theories

FORTSCHRITTE DER PHYSIK/PROGRESS OF PHYSICS, Issue 7-9 2008
M. Gomez-Reino
Abstract We study the conditions under which a generic supergravity model involving chiral and vector multiplets can admit vacua with spontaneously broken supersymmetry and realistic cosmological constant. We find that the existence of such viable vacua implies some constraints involving the curvature tensor of the scalar geometry and the charge and mass matrices of the vector fields, and also that the vector of F and D auxiliary fields defining the Goldstino direction is constrained to lie within a certain domain. We illustrate the relevance of these results through some examples and also discuss the implications of our general results on the dynamics of moduli fields in string models. This contribution is based on [1,3]. [source]

Gauged supergravities in various spacetime dimensions,

FORTSCHRITTE DER PHYSIK/PROGRESS OF PHYSICS, Issue 8 2007
M. Weidner
Abstract In this review article we study the gaugings of extended supergravity theories in various space-time dimensions. These theories describe the low-energy limit of non-trivial string compactifications. For each theory under consideration we review all possible gaugings that are compatible with supersymmetry. They are parameterized by the so-called embedding tensor which is a group theoretical object that has to satisfy certain representation constraints. This embedding tensor determines all couplings in the gauged theory that are necessary to preserve gauge invariance and supersymmetry. The concept of the embedding tensor and the general structure of the gauged supergravities are explained in detail. The methods are then applied to the half-maximal (N = 4) supergravities in d = 4 and d = 5 and to the maximal supergravities in d = 2 and d = 7. Examples of particular gaugings are given. Whenever possible, the higher-dimensional origin of these theories is identified and it is shown how the compactification parameters like fluxes and torsion are contained in the embedding tensor. [source]

The effective action of D-branes in Calabi-Yau orientifold compactifications,

FORTSCHRITTE DER PHYSIK/PROGRESS OF PHYSICS, Issue 10 2005
H. Jockers
Abstract In this review article we study type IIB superstring compactifications in the presence of space-time filling D-branes while preserving ,,=1 supersymmetry in the effective four-dimensional theory. This amount of unbroken supersymmetry and the requirement to fulfill the consistency conditions imposed by the space-time filling D-branes lead to Calabi-Yau orientifold compactifications. For a generic Calabi-Yau orientifold theory with space-time filling D3- or D7-branes we derive the low-energy spectrum. In a second step we compute the effective ,,=1 supergravity action which describes in the low-energy regime the massless open and closed string modes of the underlying type IIB Calabi-Yau orientifold string theory. These ,,=1 supergravity theories are analyzed and in particular spontaneous supersymmetry breaking induced by non-trivial background fluxes is studied. For D3-brane scenarios we compute soft-supersymmetry breaking terms resulting from bulk background fluxes whereas for D7-brane systems we investigate the structure of D- and F-terms originating from worldvolume D7-brane background fluxes. Finally we relate the geometric structure of D7-brane Calabi-Yau orientifold compactifications to ,,=1 special geometry. [source]

The supersymmetric vistas of the supergravity landscape

ANNALEN DER PHYSIK, Issue 4-5 2006
T. Ortín
Abstract In the recent times a lot of effort has been devoted to improve our knowledge about the space of string theory vacua ("the landscape") in order to find statistical grounds to justify how and why the theory selects its vacuum. Particularly interesting are those vacua that preserve some supersymmetry, which are always supersymmetric solutions of some supergravity theory. We are going to review some recent results on the problem of finding all the supersymmetric solutions of a supergravity theory. We will also review some interesting solutions that have been discovered using these methods. [source]