209 research outputs found

    3+1D Massless Weyl spinors from bosonic scalar-tensor duality

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    We consider the fermionization of a bosonic free theory characterized by the 3+1D scalar - tensor duality. This duality can be interpreted as the dimensional reduction, via a planar boundary, of the 4+1D topological BF theory. In this model, adopting the Sommerfield tomographic representation of quantized bosonic fields, we explicitly build a fermionic operator and its associated Klein factor such that it satisfies the correct anticommutation relations. Interestingly, we demonstrate that this operator satisfies the massless Dirac equation and that it can be identified with a 3+1D Weyl spinor. Finally, as an explicit example, we write the integrated charge density in terms of the tomographic transformed bosonic degrees of freedom

    Holography in flat spacetime: 4D theories and electromagnetic duality on the border

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    We consider a free topological model in 5D euclidean flat spacetime, built from two rank-2 tensor fields. Despite the fact that the bulk of the model does not have any particular physical interpretation, on its 4D planar edge nontrivial gauge field theories are recovered, whose features are entirely determined by the gauge and discrete symmetries of the bulk. In particular no 4D dynamics can be obtained without imposing a Time Reversal invariance in the bulk. Remarkably, one of the two possible edge models selected by the Time Reversal symmetries displays a true electromagnetic duality, which relates strong and weak coupling regimes. Moreover this same model, when considered on-shell, coincides with the Maxwell theory, which therefore can be thought of as a 4D boundary theory of a seemingly harmless 5D topological model.Comment: 21 pages, plain LaTeX, no figures. Version to appear on JHE

    Duality and Dimensional Reduction of 5D BF Theory

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    A planar boundary introduced \`a la Symanzik in the 5D topological BF theory, with the only requirement of locality and power counting, allows to uniquely determine a gauge invariant, non topological 4D Lagrangian. The boundary condition on the bulk fields is interpreted as a duality relation for the boundary fields, in analogy with the fermionization duality which holds in the 3D case. This suggests that the 4D degrees of freedom might be fermionic, although starting from a bosonic bulk theory. The method we propose to dimensionally reduce a Quantum Field Theory and to identify the resulting degrees of freedom can be applied to a generic spacetime dimension.Comment: 13 pages, plain LaTeX, version to appear on EPJ

    Comparison between different trap types for Drosophila suzukii in cherry orchards

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    In 2013 an experiment was carried out to compare six types of similar size traps baited with the same food attractant (“DroskiDrink”), differing for their shape and the number of entry holes. Four of the traps are already/will be soon available on the market, two of them being marketed specifically for SWD (“Drosotrap new®” and “Drosotrap®” by BIOBEST), and two being marketed for other pests (“Taptrap®” and “Vasotrap®” by Roberto Carello). The other two traps were specifically designed and hand-made on purpose (Kartell red and Bot). The trial was performed in a cherry orchard in Vignola (Modena Province, Northern Italy), area of IGP cherries; traps were placed according to a completely randomized block design and their position was changed weekly. The number of captured Drosophila suzukii (SWD) and that of other insect taxa was recorded weekly. After the first year, results show that the traps with the best performance in terms of early season captures and total number of SWD catches were “Drosotrap new” and “Bot”. However, the low selectivity towards other insect types and the uneasiness of use suggest the need of further research to improve the efficacy of these traps

    The effect of regulated deficit irrigation on growth, yield, and berry quality of grapevines (cv. Sangiovese) grafted on rootstocks with different resistance to water deficit

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    The aim of this work was to investigate the effect of full irrigation (FI), pre-veraison water deficit (RDI 1), or post-veraison water deficit (RDI 2) on growth, yield, and berry quality in container-grown, mature vines of cv. Sangiovese grafted onto either 1103P or SO4 rootstock over two consecutive growing seasons. Deficit irrigation regimes significantly affected vine water status of both rootstocks before and after veraison. Trunk diameter (TD) increment was markedly affected when water was restricted early, but not in the post-veraison period. Deficit irrigation from fruit set to veraison inhibited vegetative growth (TD, canopy volume, and weight of pruned wood) more than that applied from veraison to harvest. Yield was unaffected by either irrigation or rootstock in both years. Irrigation had a marked effect on berry and juice quality: the RDI 1 treatment induced the highest berry anthocyanin concentration, and the lowest titratable acidity (TA), which, instead, increased in the RDI 2 treatment. RDI treatments did not modify berry dry weight, soluble solid content, TA, anthocyanins, and epicarp total phenols in vines on both rootstocks

    Experimental determination of impedance and delay time of the 100 Ω\Omega meander transmission line for the SPIRAL2 Single Bunch Selector

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    International audienceThe Spiral2 driver requires a Single Bunch Selector to reduce the bunch repetition rate at the experimental targets. A 100 Ω meander line is used in the beta 0.04 medium energy line of the Spiral2 driver. The non standard characteristic impedance figure helps to reduce the pulsed power but introduces the problem of calibrated measurements. The paper describes the results of the different methods used to measure the impedance and the delay of the electrodes

    Nuove tecnologie per il monitoraggio dell'oliveto

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    I diversi sistemi olivicoli che caratterizzano l’olivicoltura umbra presentano ruoli e finalità diversi e richiedo tecniche di monitoraggio che differiscono per modalità e scopi. Il monitoraggio in olivicoltura ha subito un grande rinnovamento con l’avvento dell’agricoltura di precisone che, attraverso l’uso di dispositivi per la georeferenziazione e di sensori di prossimità e da remoto, ha consentito di ottimizzare la raccolta dei dati in campo. In questo breve contributo verranno presentate le principali caratteristiche e potenzialità del telerilevamento in olivicoltura, con particolare riferimento all’uso dei droni in olivicoltura di precisione

    On the introduction of a boundary in topological field theories

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    We study the consequences of the presence of a boundary in topological field theories in various dimensions. We characterize, univocally and on very general grounds, the field content and the symmetries of the actions which live on the boundary. We then show that these actions are covariant, despite appearances. We show also that physically relevant theories like the 2D Luttinger liquid model, or the 4D Maxwell theory, can be seen as boundary reductions of higher dimensional topological field theories, which do not display local observables.Comment: 19 pages, no figures, comments added, results unchanged, version to appear on PR

    Measurements of the First RF Prototype of the SPIRAL2 Single Bunch Selector

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    WEPD062International audienceThe single bunch selector of the Spiral2 driver uses 100 ­ travelling wave electrodes driven by fast pulse generators. A 2.5 kV, 1 kW feed-through and a vacuum chamber housing the water cooled electrodes have been designed and built. The paper reviews the whole design and reports the results of first RF and power measurements

    The LEBT Chopper for the Spiral 2 Project

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    International audienceThe Spiral 2 driver uses a slow chopper situated in the common section of the low energy beam transport line to change the beam intensity, to cut off the beam in case of critical loss and to avoid hitting the wheel structure of rotating targets. The device has to work up to 10 kV, 1 kHz repetition frequency rate and its design is based on standard power circuits, custom alarm board and vacuum feed-through. The paper summarizes the design principles and describes the test results of the final device which has been installed on the beam line test bench
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