Gauged N = 4 supergravities in five dimensions and their magnetovac backgrounds

Gauged N = 4 supergravity theories with Yang-Mills symmetry SU(2) × U(1) are constructed in five dimensions. As in four dimensions, the presence of a nonsimple gauge group leads to the existence of three distinct theories, depending (in five dimensions) on the values of the SU(2) and U(1) coupling constants. Two of the theories are distinguished by the relative sign of the coupling constants; one of these has a vacuum state exhibiting the full N = 4 anti-de Sitter supersymmetry SU(2,2|2), while the other has a scalar potential with no critical points. The third theory, in which the SU(2) coupling constant is taken to be zero, has vanishing scalar potential. This leads to vacua with spontaneously broken supersymmetry and zero cosmological constant, admitting compactification to four dimensions. All three theories possess “magnetovac” ground states with residual supersymmetry and hence presumably stable. Several of these may be interpreted as four-dimensional cosmological models.     

N = 8 supergravity in various dimensions and the implications for four dimensions

The possibilities for constructing new spontaneously broken N = 8 supergravity theories in four dimensions by applying the generalized dimensional reduction method to symmetrical theories in higher dimensions are explored.     

Massive N = 2a supergravity in ten dimensions

A new version of the non-chiral N = 2a supergravity in ten dimensions is obtained, in which the two-index tensor field of the theory “eats” the single vector field and acquires a mass in a Higgs-type mechanism. The new theory, although it contains no fundamental vectors, bears many formal resemblances to gauged supergravities (in particular, the recently constructed F(4) theory in six dimensions). The scalar potential has no extrema, but nevertheless the classical equations of motion admit a wide variety of spontaneous compactifications, many to four dimensions.     

Cancellations beyond finiteness in N=8 supergravity at three loops

We construct the three-loop four-point amplitude of N=8 supergravity using the unitarity method. The amplitude is ultraviolet finite in four dimensions. Novel cancellations, not predicted by traditional superspace power-counting arguments, render its degree of divergence in D dimensions no worse than that of N=4 super-Yang-Mills theory--a finite theory in four dimensions. Similar cancellations can be identified at all loop orders in certain unitarity cuts, suggesting that N=8 supergravity may be a perturbatively finite theory of quantum gravity.     

N=1 Dilatation supergravity

The geometrical aspect of theN=1 dilatation supergravity is here studied from the point of view of the internal structure of matter. It is shown thatN=1 supergravity may be taken to have arisen from the internal helicity of hadrons and gives rise to a torsion term in the gravitational action. This formalism is found to be in conformity with the chiral formalism of superfield developed by other authors.     

The structure ofN=16 supergravity in two dimensions

We extend the previously constructed linear system forN=16 supergravity in two dimensions by including the unphysical gravitino degrees of freedom. This theory has a residualN=16 superconformal invariance that can be bosonized to localE ₉ transformations. The modifications to the linear system described here suggest a further extension to an infinite hierarchy of fields and associated gauge transformations related toE ₉.On leave of absence from: Department of Mathematics, Massachusetts Institute of Technology, Cambridge MA 02139, USAWork supported in part by National Science Foundation Grant #85-07109     

N = 8 supergravity

The complete structure of N = 8 supergravity is presented with an optional local SO(8) invariance. The SO(8) gauge interactions break E₇ invariance, but leave the local SU(8) unaffected. Exploiting E₇ × SU(8) invariance and using explicit lowest order results, we first derive the complete action and transformation laws. Subsequently, we introduce local SO(8) invariance and prove the consistency of the theory. Possible implications of our results are discussed.     

Impossibility of adding gauge couplings to spontaneously broken N = 8 supergravity

When the four mass parameters of spontaneously broken N = 8 supergravity are taken to be equal, the theory possesses at global SU(4) symmetry. Since it contains massless vectors in the adjoint representation, it is tempting to add gauge interactions so as to make the SU(4) symmetry local. In this paper we show that it is impossible to do this in a way that is consistent with the spontaneous character of the symmetry breaking.     

The inflationary universe in the gauged N=8 supergravity induced from a superstring

N=8 supergravity can contain a large negative cosmological constant. If this supergravity was induced on a four-dimensional space-time submanifold of a ten-dimensional space by a superstring moving in the latter manifold then there exists the possibility of a mutual cancellation of the constant mentioned and a positive one arising on the given submanifold due to quantum effects from the superstring. After this the evolution of the submanifold will depend essentially on its topological properties.     

Gauged supergravities in various spacetime dimensions

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.     

The integrability of N=16 supergravity

For the maximally extended N=16 supergravity theory in two dimensions, we explicitly construct a linear system whose integrability conditions are equivalent to the full nonlinear field equations of this theory. All the (on-shell) information contained in it can thus be encoded into a single E₈ matrix and its dependence on a spectral parameter; the invariance of the equations of motion under E₉ is manifest. Possible consequences and further developments are briefly discussed.     

Super-Higgs effect in N = 1 non-minimal supergravity

The component form of the lagrangian of 20 + 20 supergravity coupled to a chiral matter field is derived. The scalar potential is shown to be different from the old-minimal Kähler-invariant form. It is demonstrated that spontaneous supersymmetry breaking occurs, and that the mass formula of the old-minimal theory in general is not valid.     

Towards a manifestly supersymmetric formulation of N = 8 supergravity on a light-cone superspace

N = 8 supergravity is formulated in the light-cone gauge. An unconstrained superfield defined on a light-cone superspace is constructed from the component formulation. The light-cone superspace is spanned by Grassmann coordinates which belong to the spinor representation of SO(7), a subgroup of the transverse SO(9).