8,893 research outputs found

    How much trade liberalization was there in the world before and after Cobden-Chevalier?

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    The Cobden-Chevalier Treaty of 1860 is regarded as central turning point in nineteenth-century trade policy, inaugurating a free trade era in Western Europe. We reexamine this story and put it into global perspective with a new database covering more than 7,500 data points for 11categories of manufactures in 41 countries and colonies around the world between 1846 and 1880. It reveals that bilateralism after 1860 reinforced a process already underway before. Nevertheless, we highlight is that trade liberalization was a global phenomenon over most of our period, so that the prominent British case appears as typical rather than exceptional.International trade, World commercial policy, World tariff history, Protectionism, Liberalization, Cobden-Chevalier

    Entropy production in the early-cosmology pionic phase

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    We point out that in the early universe, for temperatures in the approximate interval 175-80 MeV (after the quark-gluon plasma), pions carried a large share of the entropy and supported the largest inhomogeneities. Thus, we examine the production of entropy in a pion gas, particularizing to inhomogeneities of the temperature, for which we benefit from the known thermal conductivity. We finally put that entropy produced in relaxing such thermal inhomogeneities in the broad context of this relatively unexplored phase of early-universe cosmology.Comment: 10 pages, 10 figures

    One-loop WLWLW_L W_L and ZLZLZ_L Z_L scattering from the Electroweak Chiral Lagrangian with a light Higgs-like scalar

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    By including the recently discovered Higgs-like scalar φ\varphi in the Electroweak Chiral Lagrangian, and using the Equivalence Theorem, we carry out the complete one-loop computation of the elastic scattering amplitude for the longitudinal components of the gauge bosons V=W,ZV=W, Z at high energy. We also compute φφ→φφ\varphi\varphi \rightarrow \varphi\varphi and the inelastic process VV→φφVV\rightarrow \varphi\varphi, and identify the counterterms needed to cancel the divergences, namely the well known a4a_4 and a5a_5 chiral parameters plus three additional ones only superficially treated in the literature because of their dimension 8. Finally we compute all the partial waves and discuss the limitations of the one-loop computation due to only approximate unitarity.Comment: 28 pages, 19 plots, 9 Feynman-diagram sets This version revised and accepted in JHE

    Possible new resonance from WLWLW_L W_L-hhhh interchannel coupling

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    We propose and theoretically study a possible new resonance caused by strong coupling between the Higgs-Higgs and the W_L W_L (Z_L Z_L) scattering channels, without regard to the intensity of the elastic interaction in either channel at low energy (that could be weak as in the Standard Model). We expose this channel-coupling resonance from unitarity and dispersion relations encoded in the Inverse Amplitude Method, applied to the Electroweak Chiral Lagrangian with a scalar Higgs.Comment: 4 pages, 7 figure

    Unitarity, analyticity, dispersion relations and resonances in strongly interacting WLWLW_L W_L, ZLZLZ_L Z_L and hhhh scattering

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    If the Electroweak Symmetry Breaking Sector turns out to be strongly interacting, the actively investigated effective theory for longitudinal gauge bosons plus Higgs can be efficiently extended to cover the regime of saturation of unitarity (where the perturbative expansion breaks down). This is achieved by dispersion relations, whose subtraction constants and left cut contribution can be approximately obtained in different ways giving rise to different unitarization procedures. We illustrate the ideas with the Inverse Amplitude Method, one version of the N/D method and another improved version of the K-matrix. In the three cases we get partial waves which are unitary, analytical with the proper left and right cuts and in some cases poles in the second Riemann sheet that can be understood as dynamically generated resonances. In addition they reproduce at Next to Leading Order (NLO) the perturbative expansion for the five partial waves not vanishing (up to J=2) and they are renormalization scale (μ\mu) independent. Also the unitarization formalisms are extended to the coupled channel case. Then we apply the results to the elastic scattering amplitude for the longitudinal components of the gauge bosons V=W,ZV=W, Z at high energy. We also compute hh→hhh h \rightarrow h h and the inelastic process VV→hhVV\rightarrow h h which are coupled to the elastic VVVV channel for custodial isospin I=0I=0. We numerically compare the three methods for various values of the low-energy couplings and explain the reasons for the differences found in the I=J=1I=J=1 partial wave. Then we study the resonances appearing in the different elastic and coupled channels in terms of the effective Lagrangian parameters.Comment: 45 pages, 28 figure

    On Offline Evaluation of Vision-based Driving Models

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    Autonomous driving models should ideally be evaluated by deploying them on a fleet of physical vehicles in the real world. Unfortunately, this approach is not practical for the vast majority of researchers. An attractive alternative is to evaluate models offline, on a pre-collected validation dataset with ground truth annotation. In this paper, we investigate the relation between various online and offline metrics for evaluation of autonomous driving models. We find that offline prediction error is not necessarily correlated with driving quality, and two models with identical prediction error can differ dramatically in their driving performance. We show that the correlation of offline evaluation with driving quality can be significantly improved by selecting an appropriate validation dataset and suitable offline metrics. The supplementary video can be viewed at https://www.youtube.com/watch?v=P8K8Z-iF0cYComment: Published at the ECCV 2018 conferenc
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