2,989 research outputs found

    The Higher Spin/Vector Model Duality

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    This paper is mainly a review of the dualities between Vasiliev's higher spin gauge theories in AdS4 and three dimensional large N vector models, with focus on the holographic calculation of correlation functions of higher spin currents. We also present some new results in the computation of parity odd structures in the three point functions in parity violating Vasiliev theories.Comment: 55 pages, 1 figure. Contribution to J. Phys. A special volume on "Higher Spin Theories and AdS/CFT" edited by M. R. Gaberdiel and M. Vasiliev. v2: references adde

    State/Operator Correspondence in Higher-Spin dS/CFT

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    A recently conjectured microscopic realization of the dS4_4/CFT3_3 correspondence relating Vasiliev's higher-spin gravity on dS4_4 to a Euclidean Sp(N)Sp(N) CFT3_3 is used to illuminate some previously inaccessible aspects of the dS/CFT dictionary. In particular it is argued that states of the boundary CFT3_3 on S2S^2 are holographically dual to bulk states on geodesically complete, spacelike R3R^3 slices which terminate on an S2S^2 at future infinity. The dictionary is described in detail for the case of free scalar excitations. The ground states of the free or critical Sp(N)Sp(N) model are dual to dS-invariant plane-wave type vacua, while the bulk Euclidean vacuum is dual to a certain mixed state in the CFT3_3. CFT3_3 states created by operator insertions are found to be dual to (anti) quasinormal modes in the bulk. A norm is defined on the R3R^3 bulk Hilbert space and shown for the scalar case to be equivalent to both the Zamolodchikov and pseudounitary C-norm of the Sp(N)Sp(N) CFT3_3.Comment: 24 page

    Classification of lactose and mandelic acid THz spectra using subspace and wavelet-packet algorithms

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    Copyright © 2007 SPIE - The International Society for Optical Engineering.This work compares classification results of lactose, mandelic acid and dl-mandelic acid, obtained on the basis of their respective THz transients. The performance of three different pre-processing algorithms applied to the time-domain signatures obtained using a THz-transient spectrometer are contrasted by evaluating the classifier performance. A range of amplitudes of zero-mean white Gaussian noise are used to artificially degrade the signal-to-noise ratio of the time-domain signatures to generate the data sets that are presented to the classifier for both learning and validation purposes. This gradual degradation of interferograms by increasing the noise level is equivalent to performing measurements assuming a reduced integration time. Three signal processing algorithms were adopted for the evaluation of the complex insertion loss function of the samples under study; a) standard evaluation by ratioing the sample with the background spectra, b) a subspace identification algorithm and c) a novel wavelet-packet identification procedure. Within class and between class dispersion metrics are adopted for the three data sets. A discrimination metric evaluates how well the three classes can be distinguished within the frequency range 0.1-1.0 THz using the above algorithms.Xiaoxia Yin ; Sillas Hadjiloucas ; Bernd M. Fischer ; Brian W.-H. Ng ; Henrique M. Paiva ; Roberto K. H. Galvão ; Gillian C. Walker ; John W. Bowen ; Derek Abbot

    Permeating the social justice ideals of equality and equity within the context of Early Years: challenges for leadership in multi-cultural and mono-cultural primary schools

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    The ideology and commitment of social justice principles is central to Early Years practice, however, the term social justice in education is complex and remains contested. This paper explores the ideology of social justice through links between equality and equity and how it is embedded within Early Years, and what remain the potential challenges for leadership. Interviews in English multi-cultural and mono-cultural primary schools were conducted. Findings showed that the ideology of social justice, equality and equity was interpreted differently. Multi-cultural schools appear to use a greater variety of activities to embed social justice principles that involved their diverse communities more to enrich the curriculum. In mono-cultural schools leadership had to be more creative in promoting equality and equity given the smaller proportion of their diverse pupil and staff population. Tentative conclusions suggest that the vision for permeating equality and equity in Early Years, at best, is at early stages

    Non-adjacent dependency learning in Cantonese-speaking children with and without a history of specific language impairment

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    Purpose: This study investigated non-adjacent dependency learning in Cantonese-speaking children with and without a history of Specific Language Impairment (SLI) in an artificial linguistic context. Method: Sixteen Cantonese-speaking children with SLI history and 16 Cantonese-speaking children with typical language development (TLD) were tested with a non-adjacent dependency learning task using artificial languages that mimic Cantonese. Results: Children with TLD performed above chance and were able to discriminate between trained and untrained non-adjacent dependencies. However, children with SLI history performed at chance and were not able to differentiate trained versus untrained non-adjacent dependencies. Conclusions: These findings, together with previous findings with English-speaking adults and adolescents with language impairments, suggested that individuals with atypical language development, regardless of age, diagnostic status, language and culture, showed difficulties in learning non-adjacent dependencies. This study provides evidence for early impairments to statistical learning in individuals with atypical language development

    Computing prime factors with a Josephson phase qubit quantum processor

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    A quantum processor (QuP) can be used to exploit quantum mechanics to find the prime factors of composite numbers[1]. Compiled versions of Shor's algorithm have been demonstrated on ensemble quantum systems[2] and photonic systems[3-5], however this has yet to be shown using solid state quantum bits (qubits). Two advantages of superconducting qubit architectures are the use of conventional microfabrication techniques, which allow straightforward scaling to large numbers of qubits, and a toolkit of circuit elements that can be used to engineer a variety of qubit types and interactions[6, 7]. Using a number of recent qubit control and hardware advances [7-13], here we demonstrate a nine-quantum-element solid-state QuP and show three experiments to highlight its capabilities. We begin by characterizing the device with spectroscopy. Next, we produces coherent interactions between five qubits and verify bi- and tripartite entanglement via quantum state tomography (QST) [8, 12, 14, 15]. In the final experiment, we run a three-qubit compiled version of Shor's algorithm to factor the number 15, and successfully find the prime factors 48% of the time. Improvements in the superconducting qubit coherence times and more complex circuits should provide the resources necessary to factor larger composite numbers and run more intricate quantum algorithms.Comment: 5 pages, 3 figure

    Observation of the electromagnetic doubly OZI-suppressed decay J/ψ→ϕπ0J/\psi \rightarrow \phi \pi^{0}

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    Using a sample of 1.311.31 billion J/ψJ/\psi events accumulated with the BESIII detector at the BEPCII collider, we report the observation of the decay J/ψ→ϕπ0J/\psi \rightarrow \phi\pi^{0}, which is the first evidence for a doubly Okubo-Zweig-Iizuka suppressed electromagnetic J/ψJ/\psi decay. A clear structure is observed in the K+K−K^{+} K^{-} mass spectrum around 1.02 GeV/c2c^2, which can be attributed to interference between J/ψ→ϕπ0J/\psi \rightarrow \phi\pi^{0} and J/ψ→K+K−π0J/\psi \rightarrow K^{+}K^{-}\pi^{0} decays. Due to this interference, two possible solutions are found. The corresponding measured values of the branching fraction of J/ψ→ϕπ0J/\psi \to \phi\pi^{0} are [2.94±0.16(stat.)±0.16(syst.)]×10−6[2.94 \pm 0.16\text{(stat.)} \pm 0.16\text{(syst.)}] \times 10^{-6} and [1.24±0.33(stat.)±0.30(syst.)]×10−7[1.24 \pm 0.33\text{(stat.)} \pm 0.30\text{(syst.)}] \times 10^{-7}.Comment: 7 pages, 4 figures, published in Phys. Rev.

    Belle II Technical Design Report

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    The Belle detector at the KEKB electron-positron collider has collected almost 1 billion Y(4S) events in its decade of operation. Super-KEKB, an upgrade of KEKB is under construction, to increase the luminosity by two orders of magnitude during a three-year shutdown, with an ultimate goal of 8E35 /cm^2 /s luminosity. To exploit the increased luminosity, an upgrade of the Belle detector has been proposed. A new international collaboration Belle-II, is being formed. The Technical Design Report presents physics motivation, basic methods of the accelerator upgrade, as well as key improvements of the detector.Comment: Edited by: Z. Dole\v{z}al and S. Un

    Cosmological Constraints on Decaying Dark Matter

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    We present a complete analysis of the cosmological constraints on decaying dark matter. Previous analyses have used the cosmic microwave background and Type Ia supernova. We have updated them with the latest data as well as extended the analysis with the inclusion of Lyman-α\alpha forest, large scale structure and weak lensing observations. Astrophysical constraints are not considered in the present paper. The bounds on the lifetime of decaying dark matter are dominated by either the late-time integrated Sachs-Wolfe effect for the scenario with weak reionization, or CMB polarization observations when there is significant reionization. For the respective scenarios, the lifetimes for decaying dark matter are Γ−1≳100\Gamma^{-1} \gtrsim 100 Gyr and (fΓ)−1≳5.3×108 (f \Gamma) ^{-1} \gtrsim 5.3 \times 10^8 Gyr (at 95.4% confidence level), where the phenomenological parameter ff is the fraction of the decay energy deposited in baryonic gas. This allows us to constrain particle physics models with dark matter candidates through investigation of dark matter decays into Standard Model particles via effective operators. For decaying dark matter of ∼100\sim 100 GeV mass, we found that the size of the coupling constant in the effective dimension-4 operators responsible for dark matter decay has to generically be ≲10−22 \lesssim 10^{-22}. We have also explored the implications of our analysis for representative models in theories of gauge-mediated supersymmetry breaking, minimal supergravity and little Higgs.Comment: 29 pages, 6 figures. Added references and corrected typos as well as grammatical oversight
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