Constrained superfields in Supergravity

We analyze constrained superfields in supergravity. We investigate the consistency and solve all known constraints, presenting a new class that may have interesting applications in the construction of inflationary models. We provide the superspace Lagrangians for minimal supergravity models based on them and write the corresponding theories in component form using a simplifying gauge for the goldstino couplings.Comment: 24 pages. v2: JHEP final version (fixed typos, references added

General matter coupled N=2, D=5 gauged supergravity

We give the full lagrangean and supersymmetry transformation rules for D=5, N=2 supergravity interacting with an arbitrary number of vector, tensor and hyper-multiplets, with gauging of the R-symmetry group SU(2)_R as well as a subgroup K of the isometries of the scalar manifold. Among the many possible applications, this theory provides the setting where a supersymmetric brane-world scenario could occur. We comment on the presence of AdS vacua and BPS solutions that would be relevant towards a supersymmetric smooth realization of the Randall-Sundrum "alternative to compactification". We also add some remarks on the connection between this most general 5D fully coupled supergravity model and type IIB theory on the T^{11} manifold.Comment: 29+1 pages, LaTeX. References added, minor corrections, final version for Nucl. Phys.

A new class of N=1 no-scale supergravity models

We introduce a new N=1 no-scale supergravity model with F- and D-term breaking. It contains a single chiral supermultiplet T and a single U(1) vector multiplet U, gauging an axionic shift symmetry. Both supersymmetry and the gauge symmetry are spontaneously broken, with the spin-3/2, spin-1 and spin-1/2 masses sliding along a classical flat direction, with a single real massless scalar in the spectrum. The other degrees of freedom are absorbed by the massive gravitino and vector. We extend our model, under very mild conditions, to general gauge groups and matter content.Comment: 4 pages, RevTeX. Version to be published in PR

On sgoldstino-less supergravity models of inflation

We go a step further in the search for a consistent and realistic supergravity model of large-field inflation by building a class of models with the following features: during slow-roll, all the scalar fields other than the inflaton are frozen by large inflaton-dependent masses or removed from the spectrum; at the end of inflation, supersymmetry is spontaneously broken with naturally vanishing classical vacuum energy. We achieve this by combining some geometrical properties of the Kaehler potential with the consistent use of a single nilpotent chiral superfield, in one-to-one correspondence with the supersymmetry-breaking direction in field space at the vacuum.Comment: 19 pages. v2: references added and few minor changes to the text. v3: published versio

Updates in local supersymmmetry and its spontaneous breaking

We give a basic review of some recent developments in local supersymmetry breaking in 4-dimensional effective theories coming from compactifications of string and M-theory in the presence of non-trivial form and geometrical fluxes.Comment: Contribution to the Proceedings of the 43rd Erice International School of Subnuclear Physics 200

Gauged supergravity algebras from twisted tori compactifications with fluxes

Using the equivalence between Scherk-Schwarz reductions and twisted tori compactifications, we discuss the effective theories obtained by this procedure from M-theory and N =4 type II orientifold constructions with Neveu-Schwarz and Ramond-Ramond form fluxes turned on. We derive the gauge algebras of the effective theories describing their general features, in particular the symplectic embedding in the duality symmetries of the theory. The generic gauge theory is non-abelian and its gauge group is given by the semidirect product of subgroups of SL(7) or SL(p-3) x SL(9-p) for p=3,...,9, with generators describing nilpotent subalgebras of e_{7(7)} or so(6,6) (in M and type II theories respectively).Comment: Latex, 23 pages. v2 Comments and references added, section 2 expanded. v3 typos corrected, final version to appear in Nucl. Phys.

N = 1, D = 6 Supergravity: Duality and non Minimal Couplings

In this paper we present a superspace formulation of $N = 1, D = 6$ supergravity with one tensor-multiplet and an arbitrary number of vector- and hypermultiplets, in which the bosonic abelian superforms of the theory, the dilaton, the abelian gauge fields and the two-form are replaced by their S-duals i.e. four, three and two-superforms respectively, in compatibility with supersymmetry. As usual this replacement interchanges Bianchi identities with equations of motion. This formulation holds in the presence of one tensor multiplet and arbitrary numbers of hypermultiplets and abelian super-Maxwell multiplets if all couplings are minimal. We determine the consistency conditions for non-minimal couplings in $N = 1$, $D = 6$ supergravity, for which we present a particularly significant solution, namely the one associated with the Chern-Simons-Lorentz three-form which entails the Green-Schwarz anomaly cancellation mechanism. In the case of non minimal couplings it is found that the gauge fields and the two-form can still be dualized while the dilaton has to remain a zero-form.Comment: LaTeX2e file, 29 pages, uses package latexsym, no figure

Quantum corrections to broken N = 8 supergravity

We show that the one-loop effective potential of spontaneously broken N=8 supergravity is calculable and finite at all classical four-dimensional Minkowski vacua without tachyons in the spectrum. The reason is that the supertraces of the quadratic and quartic mass matrices vanish along the classically flat directions: Str M^2 = Str M^4 =0. We also show that Str M^6 = 0 but Str M^8 > 0 in a broad class of vacua with broken supersymmetry on a flat background, which includes all those explicitly identified so far. We find analytical and numerical evidence that the corresponding one-loop effective potential is negative-definite.Comment: 30 pages. v2: few misprints corrected. v3: JHEP published versio

Interactions of N Goldstini in Superspace

We study field theories with N extended non-linearly realized supersymmetries, describing the couplings of models that contain N goldstini. We review all the known formulations of the N=1 goldstino theories and we generalize them to an arbitrary number N of non-linearly realized supersymmetries. We explicitly prove the equivalence of all these extended supersymmetry breaking models containing N goldstini and reformulate the theory with N supersymmetries in terms of standard N=1 constrained superfields.Comment: 29 pages, 1 table. v2: published version. Title changed, a reference and some comments adde

Minimal scalar-less matter-coupled supergravity

We build the minimal supergravity model where the nilpotent chiral goldstino superfield is coupled to a chiral matter superfield, realising a different non-linear representation through a mixed nilpotency constraint. The model describes the spontaneous breaking of local supersymmetry in the presence of a generically massive Majorana fermion, but in the absence of elementary scalars. The sign and the size of the cosmological constant, the spectrum and the four-fermion interactions are controlled by suitable parameters.Comment: 8 page