25,924 research outputs found

    Supersymmetry anomalies in N=1\mathcal{N}=1 conformal supergravity

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    We solve the Wess-Zumino consistency conditions of N=1\mathcal{N}=1 off-shell conformal supergravity in four dimensions and determine the general form of the superconformal anomalies for arbitrary aa and cc anomaly coefficients to leading non trivial order in the gravitino. Besides the well known Weyl and RR-symmetry anomalies, we compute explicitly the fermionic Q\mathcal{Q}- and S\mathcal{S}-supersymmetry anomalies. In particular, we show that Q\mathcal{Q}-supersymmetry is anomalous if and only if RR-symmetry is anomalous. The Q\mathcal{Q}- and S\mathcal{S}-supersymmetry anomalies give rise to an anomalous supersymmetry transformation for the supercurrent on curved backgrounds admitting Killing spinors, resulting in a deformed rigid supersymmetry algebra. Our results may have implications for supersymmetric localization and supersymmetry phenomenology. Analogous results are expected to hold in dimensions two and six and for other supergravity theories. The present analysis of the Wess-Zumino consistency conditions reproduces the holographic result of arxiv:1703.04299 and generalizes it to arbitrary aa and cc anomaly coefficients.Comment: 13+13 pages; v2: minor corrections and improvements; references added; v3: further minor typos corrected; version published in JHE

    Status of the LBNE Neutrino Beamline

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    The Long Baseline Neutrino Experiment (LBNE) will utilize a neutrino beamline facility located at Fermilab to carry out a compelling research program in neutrino physics. The facility will aim a beam of neutrinos toward a detector placed at the Homestake Mine in South Dakota. The neutrinos are produced in a three-step process. First, protons from the Main Injector (60-120 GeV) hit a solid target and produce mesons. Then, the charged mesons are focused by a set of focusing horns into the decay pipe, towards the far detector. Finally, the mesons that enter the decay pipe decay into neutrinos. The parameters of the facility were determined taking into account several factors including the physics goals, the Monte Carlo modeling of the facility, spacial and radiological constraints and the experience gained by operating the NuMI facility at Fermilab. The initial beam power is expected to be ~700 kW, however some of the parameters were chosen to be able to deal with a beam power of 2.3 MW. We discuss here the status of the conceptual design and the associated challenges.Comment: 6 pages, 3 figure

    Sparse Covers for Sums of Indicators

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    For all n,ϵ>0n, \epsilon >0, we show that the set of Poisson Binomial distributions on nn variables admits a proper ϵ\epsilon-cover in total variation distance of size n2+n(1/ϵ)O(log2(1/ϵ))n^2+n \cdot (1/\epsilon)^{O(\log^2 (1/\epsilon))}, which can also be computed in polynomial time. We discuss the implications of our construction for approximation algorithms and the computation of approximate Nash equilibria in anonymous games.Comment: PTRF, to appea

    AdS/CFT correspondence and Geometry

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    In the first part of this paper we provide a short introduction to the AdS/CFT correspondence and to holographic renormalization. We discuss how QFT correlation functions, Ward identities and anomalies are encoded in the bulk geometry. In the second part we develop a Hamiltonian approach to the method of holographic renormalization, with the radial coordinate playing the role of time. In this approach regularized correlation functions are related to canonical momenta and the near-boundary expansions of the standard approach are replaced by covariant expansions where the various terms are organized according to their dilatation weight. This leads to universal expressions for counterterms and one-point functions (in the presence of sources) that are valid in all dimensions. The new approach combines optimally elements from all previous methods and supersedes them in efficiency.Comment: 30 pages, for Proceedings of the Strasburg meeting on AdS/CFT; v2: additional Comments, refs adde

    Lifshitz holography: The whole shebang

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    We provide a general algorithm for constructing the holographic dictionary for any asymptotically locally Lifshitz background, with or without hyperscaling violation, and for any values of the dynamical exponents zz and θ\theta, as well as the vector hyperscaling violating exponent, that are compatible with the null energy condition. The analysis is carried out for a very general bottom up model of gravity coupled to a massive vector field and a dilaton with arbitrary scalar couplings. The solution of the radial Hamilton-Jacobi equation is obtained recursively in the form of a graded expansion in eigenfunctions of two commuting operators, which are the appropriate generalization of the dilatation operator for non scale invariant and Lorentz violating boundary conditions. The Fefferman-Graham expansions, the sources and 1-point functions of the dual operators, the Ward identities, as well as the local counterterms required for holographic renormalization all follow from this asymptotic solution of the radial Hamilton-Jacobi equation. We also find a family of exact backgrounds with z>1z>1 and θ>0\theta>0 corresponding to a marginal deformation shifting the vector hyperscaling violating parameter and we present an example where the conformal anomaly contains the only z=2z=2 conformal invariant in d=2d=2 with four spatial derivatives.Comment: 83 pages, 1 figur

    More Supersymmetric Standard-like Models from Intersecting D6-branes on Type IIA Orientifolds

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    We present new classes of supersymmetric Standard-like models from type IIA \IT^6/(\IZ_2\times \IZ_2) orientifold with intersecting D6-branes. D6-branes can wrap general supersymmetric three-cycles of \IT^6=\IT^2\times \IT^2\times \IT^2, and any \IT^2 is allowed to be tilted. The models still suffer from additional exotics, however we obtained solutions with fewer Higgs doublets, as well as models with all three families of left-handed quarks and leptons arising from the same intersecting sector, and examples of a genuine left-right symmetric model with three copies of left-handed and right-handed families of quarks and leptons.Comment: 16 pages, REVTEX

    Correlation Functions in Holographic RG Flows

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    We discuss the computation of correlation functions in holographic RG flows. The method utilizes a recently developed Hamiltonian version of holographic renormalization and it is more efficient than previous methods. A significant simplification concerns the treatment of infinities: instead of performing a general analysis of counterterms, we develop a method where only the contribution of counterterms to any given correlator needs to be computed. For instance, the computation of renormalized 2-point functions requires only an analysis at the linearized level. We illustrate the method by discussing flat and AdS-sliced domain walls. In particular, we discuss correlation functions of the Janus solution, a recently discovered non-supersymmetric but stable AdS-sliced domain wall.Comment: 33 pages, v2 additional material on Janus solution, typos corrected, refs added, v3 additional comments on Janus solution, figure added, version to appear in JHE
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