Related papers: N=1 No-Scale Supergravity from IIB Orientifolds
N=(1,0) supergravity in six dimensions admits AdS_3\times S^3 as a vacuum solution. We extend our recent results presented in hep-th/0212323, by obtaining the complete N=4 Yang-Mills-Chern-Simons supergravity in D=3, up to quartic fermion…
We study a minimal model of U(N) gauged N=2 supergravity with one hypermultiplet parametrizing SO(4,1)/SO(4) quaternionic manifold. Local N=2 supersymmetry is known to be spontaneously broken to N=1 in the Higgs phase of U(1)_{graviphoton}…
We continue the development of the actions, S_{AFF}, by examining the cases where there are N fermionic degrees of freedom associated with a 0-brane. These actions correspond to the interaction of the N-extended super Virasoro algebra with…
The effective four-dimensional supergravity of M-theory compactified on the orbifold S^1/Z_2 and a Calabi-Yau threefold includes in general moduli supermultiplets describing massless modes of five-branes. For each brane, one of these fields…
We study total and partial supersymmetry breaking by freely acting orbifolds, or equivalently by Scherk-Schwarz compactifications, in type I string theory. In particular, we describe a four-dimensional chiral compactification with…
We show the existence of a supersymmetry breaking mechanism in string theory, where N=4 supersymmetry is broken spontaneously to N=2 and N=1 with moduli dependent gravitino masses. The spectrum of the spontaneously broken theory with lower…
We discuss supersymmetry breaking via 3-form fluxes in chiral supersymmetric type IIB orientifold vacua with D3- and D7-branes. After a general discussion of possible choices of fluxes allowing for stabilizing of a part of the moduli, we…
We consider the 3+1 visible sector to live on a Hanany-Witten D-brane construction in type IIA string theory. The messenger sector consists of stretched strings from the visible brane to a hidden D6-brane in the extra spatial dimensions. In…
We perform here a critical analysis of some non-supersymmetric gravity solutions in Type 0B string theory. We first consider the most general configuration of parallel N electric and M magnetic D3-branes. The field theory living on their…
We construct a solitonic 3-brane solution in the 5-dimensional Einstein-Hilbert-Gauss-Bonnet theory. This solitonic brane is delta-function like, and has the property that gravity is completely localized on the brane. That is, there are no…
In the on-shell formulation of $D=5 $, N=2 supergravity, compactified on $S^1/Z_2$, we extend the results of Mirabelli and Peskin describing the interaction of the bulk fields with matter which is assumed to be confined on the brane. The…
We investigate a D-brane system in which spontaneous gauge symmetry breaking occurs. The system consists of four D3-branes and three anti-D7-branes at C^3/Z_3 singularity. The singularity is blown up by vacuum expectation values of the…
This thesis studies meta- and exactly stable supersymmetry breaking mechanisms in heterotic and type IIB string theories and constructs an F-theory Grand Unified Theory model for neutrino physics in which neutrino mass is determined by the…
We show by explicit construction the existence of various four dimensional models of type II superstrings with N=2 supersymmetry, purely vector multiplet spectrum and no hypermultiplets. Among these, two are of special interest, at the…
We study N=1 four dimensional gauge theories as the world volume theory of D4-branes between NS 5-branes. We find constructions for a number of known field theory dualities involving $SU(N_c)\times SU(N_c')$ groups, coupled by matter fields…
The relative coefficients of higher derivative interactions of the IIB effective action of the form C^4, (D F_5)^4, F_5^8, ... (where C is the Weyl tensor and F_5 is the five-form field strength) are motivated by supersymmetry arguments. It…
We present a theory of N=2 chiral supergravity in (10+2)-dimensions. This formulation is similar to N=1 supergravity presented recently using null-vectors in 12D. In order to see the consistency of this theory, we perform a simple…
We analyse the geometrical structure of supersymmetric solutions of type II supergravity of the form R^{1,9-n} x M_n with non-trivial NS flux and dilaton. Solutions of this type arise naturally as the near-horizon limits of wrapped NS…
In the framework of a five-dimensional three-brane model with quasi-localized gravitons we evaluate metric perturbations induced on the positive tension brane by matter residing thereon. We find that at intermediate distances, the effective…
It is advocated that the superembedding approach is a generic covariant method for the description of superbranes as models of (partial) spontaneous supersymmetry breaking. As an illustration we construct (in the framework of…