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Riccardo D'Auria

Publications and source records attributed to Riccardo D'Auria.

At least 37 records · Page 2Linked to original sources
arXiv2005

Supersymmetric completion of M-theory 4D-gauge algebra from twisted tori and fluxes

We present the supersymmetric completion of the M-theory free differential algebra resulting from a compactification to four dimensions on a twisted seven-torus with 4-form and 7-form fluxes turned on. The super--curvatures are given and the local supersymmetry transformations derived. Dual formulations of the theory are discussed in connection with classes of gaugings corresponding to diverse choices of vacua. This also includes seven dimensional compactifications on more general spaces not described by group manifolds.

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arXiv2005

Compactifications on twisted tori with fluxes and free differential algebras

We describe free differential algebras for non-abelian one and two form gauge potentials in four dimensions deriving the integrability conditions for the corresponding curvatures. We show that a realization of these algebras occurs in M-theory compactifications on twisted tori with constant four-form flux, due to the presence of antisymmetric tensor fields in the reduced theory.

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arXiv2004

Scalar potential for the gauged Heisenberg algebra and a non-polynomial antisymmetric tensor theory

We study some issues related to the effective theory of Calabi-Yau compactifications with fluxes in Type II theories. At first the scalar potential for a generic electric abelian gauging of the Heisenberg algebra, underlying all possible gaugings of RR isometries, is presented and shown to exhibit, in some circumstances, a "dual'' no-scale structure under the interchange of hypermultiplets and vector multiplets. Subsequently a new setting of such theories, when all RR scalars are dualized into antisymmetric tensors, is discussed. This formulation falls in the class of non-polynomial tensor theories considered long ago by Freedman and Townsend and it may be relevant for the introduction of both electric and magnetic charges.

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arXiv2004

N=2 Supergravity Lagrangian Coupled to Tensor Multiplets with Electric and Magnetic Fluxes

We derive the full N=2 supergravity Lagrangian which contains a symplectic invariant scalar potential in terms of electric and magnetic charges. As shown in reference [1], the appearance of magnetic charges is allowed only if tensor multiplets are present and a suitable Fayet-Iliopoulos term is included in the fermion transformation laws. We generalize the procedure in the quoted reference by adding further a Fayet-Iliopoulos term which allows the introduction of electric charges in such a way that the potential and the equations of motion of the theory are symplectic invariant. The theory is further generalized to include an ordinary electric gauging and the form of the resulting scalar potential is given.

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arXiv2004

Homogeneous Special Manifolds, Orientifolds and Solvable Coordinates

We discuss some geometrical properties of the underlying N=2 geometry which encompasses some low--energy aspects of N=1 orientifolds as well as four dimensional N=2 Lagrangians including bulk and open string moduli.In the former case we illustrate how properly defined involutions allow to define N=1 Kaehler subspaces of special quaternionic manifolds. In the latter case we show that the full shift symmetry of the brane coordinates, which is abelian in the rigid limit, is partially distorted by bulk fields to a nilpotent algebra.

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arXiv2003

D=4, N=2 Gauged Supergravity in the Presence of Tensor Multiplets

Using superspace techniques we construct the general theory describing D=4, N=2 supergravity coupled to an arbitrary number of vector and scalar--tensor multiplets. The scalar manifold of the theory is the direct product of a special Kaehler and a reduction of a Quaternionic-Kaehler manifold. We perform the electric gauging of a subgroup of the isometries of such manifold as well as ``magnetic'' deformations of the theory discussing the consistency conditions arising in this process. The resulting scalar potential is the sum of a symplectic invariant part (which in some instances can be recast into the standard form of the gauged N =2 theory) and of a non--invariant part, both giving new deformations. We also show the relation of such theories to flux ompactifications of type II string theories.

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arXiv2003

N=4 Supergravity Lagrangian for Type IIB Orientifold on T^6/Z_2 in Presence of Fluxes and D3-Branes

We derive the Lagrangian and the transformation laws of N=4 gauged supergravity coupled to matter multiplets whose sigma-model of the scalars is SU(1,1)/U(1)x SO(6,6+n)/SO(6)xSO(6+n) and which corresponds to the effective Lagrangian of the Type IIB string compactified on the T^6/Z_2 orientifold with fluxes turned on and in presence of n D3-branes. The gauge group is T^12 x G where G is the gauge group on the brane and T^12 is the gauge group on the bulk corresponding to the gauged translations of the R-R scalars coming from the R-R four--form. The N=4 bulk sector of this theory can be obtained as a truncation of the Scherk-Schwarz spontaneously broken N=8 supergravity. Consequently the full bulk spectrum satisfies quadratic and quartic mass sum rules, identical to those encountered in Scherk-Schwarz reduction gauging a flat group. This theory gives rise to a no scale supergravity extended with partial super-Higgs mechanism.

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arXiv2002

No-scale N=4 supergravity coupled to Yang-Mills: the scalar potential and super-Higgs effect

We derive the scalar potential of the effective theory of type IIB orientifold with 3-form fluxes turned on in presence of non abelian brane coordinates. N=4 supergravity predicts a positive semidefinite potential with vanishing cosmological constant in the vacuum of commuting coordinates, with a classical moduli space given by three radial moduli and three RR scalars which complete three copies of the coset (U(1,1+n)/U(1)\otimes U(1+n)), together with 6n D3-branes coordinates, n being the rank of the gauge group G. Implications for the super Higgs mechanism are also discussed.

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arXiv2002

N=4 gauged supergravity and a IIB orientifold with fluxes

We analyze the properties of a spontaneously broken D=4, N=4 supergravity without cosmological constant, obtained by gauging translational isometries of its classical scalar manifold. This theory offers a suitable low energy description of the super-Higgs phases of certain Type-IIB orientifold compactifications with 3-form fluxes turned on. We study its N=3,2,1,0 phases and their classical moduli spaces and we show that this theory is an example of no-scale extended supergravity.

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arXiv2002

Supersymmetry reduction of N-extended supergravities in four dimensions

We consider the possible consistent truncation of N-extended supergravities to lower N' theories. The truncation, unlike the case of N-extended rigid theories, is non trivial and only in some cases it is sufficient just to delete the extra N-N' gravitino multiplets. We explore different cases (starting with N=8 down to N'\geq 2) where the reduction implies restrictions on the matter sector. We perform a detailed analysis of the interesting case N=2 \to N=1. This analysis finds applications in different contexts of superstring and M-theory dynamics.

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arXiv2002

D=6, N=2, F(4)-Supergravity with supersymmetric de Sitter Background

We show that there exists a supersymmetric de Sitter background for the D=6, N=2, F(4) supergravity preserving the compact R-symmetry and gauging with respect to the conventional Anti de Sitter version of the theory. We construct the gauged matter coupled F(4) de Sitter supergravity explicitly and show that it contains ghosts in the vector sector.

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arXiv2001

Matter Coupled F(4) Gauged Supergravity Lagrangian

We construct the so far unknown Lagrangian of D=6, N=2 F(4) Supergravity coupled to an arbitrary number of vector multiplets whose scalars span the coset manifold SO(4,n)/{SO(4) x SO(n)}. This is done first in the ungauged case and then extended to the compact gauging of SU(2) x G, where SU(2) is the R-symmetry diagonal subgroup of SU(2)_L x SU(2)_R = SO(4) and G is a compact subgroup of SO(n), n being the number of vector multiplets, and such that dim G = n. The knowledge of the Lagrangian allows in principle to refine the AdS_6/CFT_5 correspondence already discussed, as far as supersymmetric multiplets are concerned, in a previous related paper. With respect to the latter we also give a more exaustive treatment of the construction of the theory at the level of superspace Bianchi identities and in particular of the scalar potential.

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arXiv2001

AdS_6/CFT_5 correpondence for F(4) Supergravity

F(4) supergravity, the gauge theory of the exceptional six-dimensional Anti-de Sitter superalgebra, is coupled to an arbitrary number of vector multiplets whose scalar components parametrize the quaternionic manifold SO(4,n)/SO(4)\times SO(n). By gauging the compact subgroup SU(2)_d \otimes G, where SU(2)_d is the diagonal subgroup of SO(4)= SU(2)_L\otimes SU(2)_R (the R-symmetry group of six-dimensional Poincare' supergravity) and G is a compact group such that dim G = n. The potential admits an AdS background for g=3m, as the pure F(4)-supergravity. The boundary F(4) superconformal fields are realized in terms of a singleton superfield (hypermultiplet) in harmonic superspace with flag manifold SU(2)/U(1)=S^2. We analize the spectrum of short representations in terms of superconformal primaries and predict general features of the K-K specrum of massive type IIA supergravity compactified on warped AdS_6\otimes S^4.

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arXiv1999

KK Spectroscopy of Type IIB Supergravity on AdS_5 x T^{11}

We give full details for the computation of the Kaluza--Klein mass spectrum of Type IIB Supergravity on AdS_5 x T^{11}, with T^{11}=SU(2)xSU(2)/U(1), that has recently lead to both stringent tests and interesting predictions on the AdS_5/CFT_4 correspondence for N=1 SCFT's (hep-th/9905226). We exhaustively explain how KK states arrange into SU(2,2|1) supermultiplets, and stress some relevant features of the T^{11} manifold, such as the presence of topological modes in the spectrum originating from the existence of non-trivial 3-cycles. The corresponding Betti vector multiplet is responsible for the extra baryonic symmetry in the boundary CFT. More generally, we use the simple T^{11} coset as a laboratory to revive the technique and show the power of KK harmonic expansion, in view of the present attempts to probe along the same lines also M-theory compactifications and the AdS_4/CFT_3 map.

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arXiv1999

Spectrum of Type IIB Supergravity on AdS_5 x T^{11}: Predictions on N = 1 SCFT's

We derive the full Kaluza-Klein spectrum of type IIB supergravity compactified on AdS_5 x T^{11} with T^{11} = (SU(2) x SU(2))/U(1). From the knowledge of the spectrum and general multiplet shortening conditions, we make a refined test of the AdS/CFT correspondence, by comparison between various shortenings of SU(2,2|1) supermultiplets on AdS_5 and different families of boundary operators with protected dimensions. Additional towers of long multiplets with rational dimensions, that are not protected by supersymmetry, are also predicted from the supergravity analysis.

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arXiv1999

BPS Black Holes in Superegravity

In these lectures we explain the concept of supergravity p-branes and BPS black holes. Introducing an audience of general relativists to all the necessary geometry related with extended supergravity (special geometry, symplectic embeddings and the like) we describe the general properties of N=2 black holes, the structure of central charges in extended supergravity and the description of black hole entropy as an invariant of the U duality group. Then, after explaining the concept and the use of solvable Lie algebras we present the detailed construction of 1/2, 1/4 and 1/8 supersymmetry preserving black holes in the context of N=8 supergravity. The Lectures are meant to be introductory and self contained for non supersymmetry experts but at the same time fully detailed and complete on the subject.

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