1,720,989 research outputs found
Five-dimensional gauged supergravity and the brane-world
No full textRandall-Sundrum scenarios view our Universe as a membrane embedded in a higher dimensional spacetime. We report on the status of their potential realisation within a supersymmetric theory such as five-dimensional matter coupled N = 2 gauged supergravity
First order flows for N=2 extremal black holes and duality invariants
No full textWe derive explicitly the superpotential W for the non-BPS branch of N=2 extremal black holes in terms of duality invariants of special geometry. Although this is done for a one-modulus case (the t^3 model), the example gives black holes and captures the basic distinction from previous attempts on the quadratic series (vanishing C tensor) and from the other Z=0 cases. The superpotential W turns out to be a non-polynomial expression (containing radicals) of the basic duality invariant quantities. These are the same which enter in the quartic invariant I_4 for N=2 theories based on symmetric spaces. Using the flow equations generated by W, we also provide the analytic general solution for the warp factor and for the scalar field supporting the non-BPS black holes
K K spectroscopy of type IIB supergravity on AdS(5) x T**11
No full textWe 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
Universality of the superpotential for d = 4 extremal black holes
No full textWe provide a general strategy to obtain the superpotential W for both BPS and non-BPS extremal black holes in N=2 four dimensional supergravities based on symmetric spaces. This extends the construction of W in terms of U-duality invariants that was presented in previous work on the model. As an application, we explicitly provide W and the solutions to the related gradient flows for the and stu models. The procedure is shown to hold also for the full N=8 theory. The role of flat directions in moduli space is clarified.We provide a general strategy to obtain the superpotential W for both BPS and non-BPS extremal black holes in N = 2 four-dimensional supergravities based on symmetric spaces. This extends the construction of W in terms of U-duality invariants that was presented in previous work on the t 3 model. As an application, we explicitly provide W and the solutions to the related gradient flows for the st 2 and stu models. The procedure is shown to hold also for the full N = 8 theory. The role of flat directions in moduli space is clarified.We provide a general strategy to obtain the superpotential W for both BPS and non-BPS extremal black holes in N=2 four dimensional supergravities based on symmetric spaces. This extends the construction of W in terms of U-duality invariants that was presented in previous work on the model. As an application, we explicitly provide W and the solutions to the related gradient flows for the and stu models. The procedure is shown to hold also for the full N=8 theory. The role of flat directions in moduli space is clarified
Flow equations for Non-BPS extremal black holes
Full text linkWe exploit some common features of black hole and domain wall solutions of (super)gravity theories coupled to scalar fields and construct a class of stable extremal black holes that are non-BPS, but still can be described by first-order differential equations. These are driven by a "superpotential'', which replaces the central charge Z in the usual black hole potential. We provide a general procedure for finding this class and deriving the associated "superpotential''. We also identify some other cases which do not belong to this class, but show a similar behaviour
General matter coupled N=2, D=5 gauged supergravity
No full textWe 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
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Superconformal field theories from IIB spectroscopy on AdS(5) x T-11
No full textWe report on tests of the AdS/CFT correspondence that are made possible by complete knowledge of the Kaluza-Klein mass spectrum of type IIB supergravity on with T^{11}=SU(2)^2/U(1). After briefly discussing general multiplet shortening conditions in SU(2,2|1) and PSU(2,2|4), we compare various types of short SU(2,2|1) supermultiplets on AdS_5 and different families of boundary operators with protected dimensions. The supergravity analysis predicts the occurrence in the SCFT at leading order in N and g_s N, of extra towers of long multiplets whose dimensions are rational but not protected by supersymmetry.We report on tests of the AdS/CFT correspondence that are made possible by complete knowledge of the Kaluza-Klein mass spectrum of type IIB supergravity on with T^{11}=SU(2)^2/U(1). After briefly discussing general multiplet shortening conditions in SU(2,2|1) and PSU(2,2|4), we compare various types of short SU(2,2|1) supermultiplets on AdS_5 and different families of boundary operators with protected dimensions. The supergravity analysis predicts the occurrence in the SCFT at leading order in N and g_s N, of extra towers of long multiplets whose dimensions are rational but not protected by supersymmetry
- …
