35,163 research outputs found

    Large-small dualities between periodic collapsing/expanding branes and brane funnels

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    We consider space and time dependent fuzzy spheres S2pS^{2p} arising in D1D(2p+1)D1-D(2p+1) intersections in IIB string theory and collapsing D(2p)-branes in IIA string theory. In the case of S2S^2, where the periodic space and time-dependent solutions can be described by Jacobi elliptic functions, there is a duality of the form rr to 1r{1 \over r} which relates the space and time dependent solutions. This duality is related to complex multiplication properties of the Jacobi elliptic functions. For S4S^4 funnels, the description of the periodic space and time dependent solutions involves the Jacobi Inversion problem on a hyper-elliptic Riemann surface of genus 3. Special symmetries of the Riemann surface allow the reduction of the problem to one involving a product of genus one surfaces. The symmetries also allow a generalisation of the rr to 1r{1 \over r} duality. Some of these considerations extend to the case of the fuzzy S6S^6.Comment: Latex, 50 pages, 2 figures ; v2 : a systematic typographical error corrected + minor change

    A Declarative Semantics for CLP with Qualification and Proximity

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    Uncertainty in Logic Programming has been investigated during the last decades, dealing with various extensions of the classical LP paradigm and different applications. Existing proposals rely on different approaches, such as clause annotations based on uncertain truth values, qualification values as a generalization of uncertain truth values, and unification based on proximity relations. On the other hand, the CLP scheme has established itself as a powerful extension of LP that supports efficient computation over specialized domains while keeping a clean declarative semantics. In this paper we propose a new scheme SQCLP designed as an extension of CLP that supports qualification values and proximity relations. We show that several previous proposals can be viewed as particular cases of the new scheme, obtained by partial instantiation. We present a declarative semantics for SQCLP that is based on observables, providing fixpoint and proof-theoretical characterizations of least program models as well as an implementation-independent notion of goal solutions.Comment: 17 pages, 26th Int'l. Conference on Logic Programming (ICLP'10

    Quantum canonical tensor model and an exact wave function

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    Tensor models in various forms are being studied as models of quantum gravity. Among them the canonical tensor model has a canonical pair of rank-three tensors as dynamical variables, and is a pure constraint system with first-class constraints. The Poisson algebra of the first-class constraints has structure functions, and provides an algebraically consistent way of discretizing the Dirac first-class constraint algebra for general relativity. This paper successfully formulates the Wheeler-DeWitt scheme of quantization of the canonical tensor model; the ordering of operators in the constraints is determined without ambiguity by imposing Hermiticity and covariance on the constraints, and the commutation algebra of constraints takes essentially the same from as the classical Poisson algebra, i.e. is first-class. Thus one could consistently obtain, at least locally in the configuration space, wave functions of "universe" by solving the partial differential equations representing the constraints, i.e. the Wheeler-DeWitt equations for the quantum canonical tensor model. The unique wave function for the simplest non-trivial case is exactly and globally obtained. Although this case is far from being realistic, the wave function has a few physically interesting features; it shows that locality is favored, and that there exists a locus of configurations with features of beginning of universe.Comment: 17 pages. Section 2 expanded to include fuzzy-space interpretation, and other minor change

    Fuzzy qualitative simulation with multivariate constraints

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    Giant Gravitons in type IIA PP-wave Background

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    We examine giant gravitons with a worldvolume magnetic flux qq in type IIA pp-wave background and find that they can move away from the origin along x4x^4 direction in target space satisfying Rx4=qRx^4=-q. This nontrivial relation can be regarded as a complementary relation of the giant graviton on IIA pp-wave and is shown to be connected to the spacetime uncertainty principle. The giant graviton is also investigated in a system of N D0-branes as a fuzzy sphere solution. It is observed that x4x^4 enters into the fuzzy algebra as a deformation parameter. Such a background dependent Myers effect guarantees that we again get the crucial relation of our giant graviton. In the paper, we also find a BIon configuration on the giant graviton in this background.Comment: 10 pages, no figure, content added, typo corrected, reference adde
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