846 research outputs found

    Economic and environmental effects of border tax adjustments

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    Taxing imports from regions which are not subject to climate policy and subsidizing exports into these regions have recently been proposed to address presumed negative effects of the EU Emissions Trading Scheme (EU ETS) on industry competitiveness and carbon leakage. This paper analyzes the economic and environmental effects of alternative border tax adjustment (BTA) mechanisms using an extended version of the GTAP-E model that explicitly includes domestic trade and transport margins. The BTAs are imposed on regions which have not committed to emission targets under the Kyoto Protocol or which failed to ratify the Kyoto Protocol. The analyses distinguish between effects of the BTAs on the EU15 countries and on the rest of the EU (REU). Likewise, the analyses single out the effects of climate policy with and without BTAs on domestic output changes which are due to changes in import competition and export competitiveness. Implementing a BTA whose power is equal to the percentage change in production costs in the energy-intensive sectors in the EU has different impacts for those sectors in the EU15 countries compared with the REU countries. In the EU15, the BTA effectively neutralizes import competition in the energy-intensive sectors while enhancing the export competitiveness of these sectors. Conversely, in the REU, the BTA is not effective in neutralizing increased import competition or decreased export competitiveness because the majority of trade by the REU is with countries/regions that are not included in the BTA. Overall, implementing a BTA has little effect on the marginal abatement costs of achieving the emission reductions in the Kyoto Protocol and does little in reducing carbon leakage. --

    The Generalized Hartle-Hawking Initial State: Quantum Field Theory on Einstein Conifolds

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    Recent arguments have indicated that the sum over histories formulation of quantum amplitudes for gravity should include sums over conifolds, a set of histories with more general topology than that of manifolds. This paper addresses the consequences of conifold histories in gravitational functional integrals that also include scalar fields. This study will be carried out explicitly for the generalized Hartle-Hawking initial state, that is the Hartle-Hawking initial state generalized to a sum over conifolds. In the perturbative limit of the semiclassical approximation to the generalized Hartle-Hawking state, one finds that quantum field theory on Einstein conifolds is recovered. In particular, the quantum field theory of a scalar field on de Sitter spacetime with RP3RP^3 spatial topology is derived from the generalized Hartle-Hawking initial state in this approximation. This derivation is carried out for a scalar field of arbitrary mass and scalar curvature coupling. Additionally, the generalized Hartle-Hawking boundary condition produces a state that is not identical to but corresponds to the Bunch-Davies vacuum on RP3RP^3 de Sitter spacetime. This result cannot be obtained from the original Hartle-Hawking state formulated as a sum over manifolds as there is no Einstein manifold with round RP3RP^3 boundary.Comment: Revtex 3, 31 pages, 4 epsf figure

    Bound States in Sharply Bent Waveguides: Analytical and Experimental Approach

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    Quantum wires and electromagnetic waveguides possess common features since their physics is described by the same wave equation. We exploit this analogy to investigate experimentally with microwave waveguides and theoretically with the help of an effective potential approach the occurrence of bound states in sharply bent quantum wires. In particular, we compute the bound states, study the features of the transition from a bound to an unbound state caused by the variation of the bending angle and determine the critical bending angles at which such a transition takes place. The predictions are confirmed by calculations based on a conventional numerical method as well as experimental measurements of the spectra and electric field intensity distributions of electromagnetic waveguides

    The Beam Conditions Monitor of the LHCb Experiment

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    The LHCb experiment at the European Organization for Nuclear Research (CERN) is dedicated to precision measurements of CP violation and rare decays of B hadrons. Its most sensitive components are protected by means of a Beam Conditions Monitor (BCM), based on polycrystalline CVD diamond sensors. Its configuration, operation and decision logics to issue or remove the beam permit signal for the Large Hadron Collider (LHC) are described in this paper.Comment: Index Terms: Accelerator measurement systems, CVD, Diamond, Radiation detector

    Dynamic shear suppression in quantum phase space

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    © 2019 American Physical Society. All rights reserved.Classical phase space flow is inviscid. Here we show that in quantum phase space Wigner's probability current J can be effectively viscous. This results in shear suppression in quantum phase space dynamics which enforces Zurek's limit for the minimum size scale of spotty structures that develop dynamically. Quantum shear suppression is given by gradients of the quantum terms of J's vorticity. Used as a new measure of quantum dynamics applied to several evolving closed conservative 1D bound state systems, we find that shear suppression explains the saturation at Zurek's scale limit and additionally singles out special quantum states.Peer reviewe

    Rydberg Wave Packets are Squeezed States

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    We point out that Rydberg wave packets (and similar ``coherent" molecular packets) are, in general, squeezed states, rather than the more elementary coherent states. This observation allows a more intuitive understanding of their properties; e.g., their revivals.Comment: 7 pages of text plus one figure available in the literature, LA-UR 93-2804, to be published in Quantum Optics, LaTe
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