839 research outputs found

    Graviton-Form Invariants in D=11 Supergravity

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    We complete an earlier derivation of the 4-point bosonic scattering amplitudes, and of the corresponding linearized local supersymmetric invariants in D=11 supergravity, by displaying the form-curvature, F^2 R^2, terms.Comment: 2 pages. One typo corrected; note added on comparison with D=10 string expansion invariants. Accepted for publication in Phys. Rev. D1

    Free Spin 2 Duality Invariance Cannot be Extended to GR

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    We show by explicit computation that the recently discovered duality invariance of D=4 linearized gravity fails, already at first self-interacting, cubic, approximation of GR. In contrast, the cubic Yang-Mills correction to Maxwell does admit a simple deformed duality.Comment: 11 Page

    Counterterms/M-theory Corrections to D=11 Supergravity

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    We construct a local on-shell invariant in D=11 supergravity from the nonlocal four-point tree scattering amplitude.Its existence, together with earlier arguments, implies non-renormalizability of the theory at lowest possible, two loop, level. This invariant, whose leading bosonic terms are exhibited, may also express the leading, "zero-slope", M−-theory corrections to its D=11 supergravity limit.Comment: 16 pages RevTe

    Definition of Chern-Simons Terms in Thermal QED_3 Revisited

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    We present two compact derivations of the correct definition of the Chern-Simons term in the topologically non trivial context of thermal QED3QED_3. One is based on a transgression descent from a D=4 background connection, the other on embedding the abelian model in SU(2). The results agree with earlier cohomology conclusions and can be also used to justify a recent simple heuristic approach. The correction to the naive Chern-Simons term, and its behavior under large gauge transformations are displayed.Comment: 9 pages, RevTex, no figures, new derivation from non abelian embedding adde

    No Cosmological D=11 Supergravity

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    We show, in two complementary ways, that D=11 supergravity---in contrast to all its lower dimensional versions---forbids a cosmological extension. First, we linearize the putative model about an Anti de Sitter background and show that it cannot even support a "global" supersymmetry invariance; hence there is no Noether construction that can lead to a local supersymmetry. This is true with the usual 4-form field as well as for a "dual", 7-form, starting point. Second, a cohomology argument, starting from the original full nonlinear theory, establishes the absence of deformations involving spin 3/2 mass and cosmological terms. In both approaches, it is the form field that is responsible for the obstruction. ``Dualizing'' the cosmological constant to an 11-form field also fails

    Duality invariance of s ≥ 3/2 fermions in AdS

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    We show that in D = 4 AdS, s ≥ 3/2 partially massless (PM) fermions retain the duality invariances of their flat space massless counterparts. They have tuned ratios m^2/M^2 ≠ 0 that turn them into sums of effectively massless unconstrained helicity ±(s,···, 3/2) excitations, shorn of the lowest (non-dual) helicity ±1/2-rung and — more generally — of succeeding higher rung as well. Each helicity mode is separately duality invariant, like its flat space counterpart

    BPS Wilson loops and Bremsstrahlung function in ABJ(M): a two loop analysis

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    We study a family of circular BPS Wilson loops in N=6 super Chern-Simons-matter theories, generalizing the usual 1/2-BPS circle. The scalar and fermionic couplings depend on two deformation parameters and these operators can be considered as the ABJ(M) counterpart of the DGRT latitudes defined in N=4 SYM. We perform a complete two-loop analysis of their vacuum expectation value, discuss the framing dependence and propose a general relation with cohomologically equivalent bosonic operators. We make an all-loop proposal for computing the Bremsstrahlung function associated to the 1/2-BPS cusp in terms of these generalized Wilson loops. When applied to our two-loop result it reproduces the known expression. Finally, we comment on the generalization of this proposal to the bosonic 1/6-BPS case.Comment: 46 pages, 6 figures; references adde

    A matrix model for the latitude Wilson loop in ABJM theory

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    In ABJ(M) theory, we propose a matrix model for the exact evaluation of BPS Wilson loops on a latitude circular contour, so providing a new weak-strong interpolation tool. Intriguingly, the matrix model turns out to be a particular case of that computing torus knot invariants in U(N1∣N2)U(N_1|N_2) Chern-Simons theory. At weak coupling we check our proposal against a three-loop computation, performed for generic framing, winding number and representation. The matrix model is amenable of a Fermi gas formulation, which we use to systematically compute the strong coupling and genus expansions. For the fermionic Wilson loop the leading planar behavior agrees with a previous string theory prediction. For the bosonic operator our result provides a clue for finding the corresponding string dual configuration. Our matrix model is consistent with recent proposals for computing Bremsstrahlung functions exactly in terms of latitude Wilson loops. As a by-product, we extend the conjecture for the exact B1/6θB^{\theta}_{1/6} Bremsstrahlung function to generic representations and test it with a four-loop perturbative computation. Finally, we propose an exact prediction for B1/2B_{1/2} at unequal gauge group ranks.Comment: 73 pages; v2: several improvements, JHEP published versio

    Correlators of Hopf Wilson loops in the AdS/CFT correspondence

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    We study at quantum level correlators of supersymmetric Wilson loops with contours lying on Hopf fibers of S3S^3. In N=4\mathcal{N}=4 SYM theory the strong coupling analysis can be performed using the AdS/CFT correspondence and a connected classical string surface, linking two different fibers, is presented. More precisely, the string solution describes oppositely oriented fibers with the same scalar coupling and depends on an angular parameter, interpolating between a non-BPS configuration and a BPS one. The system can be thought as an alternative deformation of the ordinary antiparallel lines giving the static quark-antiquark potential, that is indeed correctly reproduced, at weak and strong coupling, as the fibers approach one another.Comment: 38 pages, 5 figure
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