9,954 research outputs found

    Increasing CAFE Standards: Still a Very Bad Idea

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    In a recent Joint Center Working Paper, Gerard and Lave respond to our recent work critiquing proposed increases in existing Corporate Average Fuel Economy (CAFE) standards. Gerard and Laveassert that, at least in the right environment, there is a place for CAFE standards. We suggest, however, that Gerard and Lavehave not really made any dent in our arguments, and have not provided any rationale for the CAFE program to exist. Indeed, much of the Gerard and Lave'sargument is self-contradictory.

    TRANSACTION CHAIN APPROACH TO THE REGULATION OF THE NONPOINT WATER POLLUTION FROM FARMS-RUNOFF

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    We offer a decentralized solution to the asymmetric information and hidden action problems in the nonpoint source (NPS) pollution case. Farmers in the same watershed generate homogeneous NPS pollution. The regulator, R, pays for (or represents a group of point-source, PS, polluters who pay for) pollution reduction credits earned by the group of the farmers. To resolve the asymmetric information problem, R is concerned with only the total level of the abatement achieved, while the group of farmers (called the Association, A), undertakes responsibility to distribute the payment so as to induce farmers to deliver abatement. We show that A can devise an optimal contract to deal with the farmers' hidden action problem. We identify the restrictions under which such a policy can be implemented, evaluate its effects on the product market, and show that in the NPS case information rents are higher than in the PS case.Environmental Economics and Policy,

    Shadows of the Planck Scale: The Changing Face of Compactification Geometry

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    By studying the effects of the shape moduli associated with toroidal compactifications, we demonstrate that Planck-sized extra dimensions can cast significant ``shadows'' over low-energy physics. These shadows can greatly distort our perceptions of the compactification geometry associated with large extra dimensions, and place a fundamental limit on our ability to probe the geometry of compactification simply by measuring Kaluza-Klein states. We also discuss the interpretation of compactification radii and hierarchies in the context of geometries with non-trivial shape moduli. One of the main results of this paper is that compactification geometry is effectively renormalized as a function of energy scale, with ``renormalization group equations'' describing the ``flow'' of geometric parameters such as compactification radii and shape angles as functions of energy.Comment: 7 pages, LaTeX, 2 figure

    The embedding of the spacetime in five dimensions: an extension of Campbell-Magaard theorem

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    We extend Campbell-Magaard embedding theorem by proving that any n-dimensional semi-Riemannian manifold can be locally embedded in an (n+1)-dimensional Einstein space. We work out some examples of application of the theorem and discuss its relevance in the context of modern higher-dimensional spacetime theories.Comment: 22pages, Revte

    A computer program to predict rotor rotational noise of a stationary rotor from blade loading coefficient

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    The programing language used is FORTRAN IV. A description of all main and subprograms is provided so that any user possessing a FORTRAN compiler and random access capability can adapt the program to his facility. Rotor blade surface-pressure spectra can be used by the program to calculate: (1) blade station loading spectra, (2) chordwise and/or spanwise integrated blade-loading spectra, and (3) far-field rotational noise spectra. Any of five standard inline functions describing the chordwise distribution of the blade loading can be chosen in order to study parametrically the acoustic predictions. The program output consists of both printed and graphic descriptions of the blade-loading coefficient spectra and far-field acoustic spectrum. The results may also be written on binary file for future processing. Examples of the application of the program along with a description of the rotational noise prediction theory on which the program is based are also provided

    Quasi-Localization of Gravity by Resonant Modes

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    We examine the behaviour of gravity in brane theories with extra dimensions in a non-factorizable geometry. We find that for metrics which are asymptotically flat far from the brane there is a resonant graviton mode at zero energy. The presence of this resonance ensures quasi-localization of gravity, whereby at intermediate scales the gravitational laws on the brane are approximately four dimensional. However, for scales larger than the lifetime of the graviton resonance the five dimensional laws of gravity will be reproduced due to the decay of the four dimensional graviton. We also present a simple classification of the possible types of effective gravity theories on the brane that can appear for general non-factorizable background theories.Comment: 8 pages, 3 figures included. Requires JHEP.cls. Typos fixed, note and references added. Added expression for width of resonanc

    Dynamically Warped Theory Space and Collective Supersymmetry Breaking

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    We study deconstructed gauge theories in which a warp factor emerges dynamically and naturally. We present nonsupersymmetric models in which the potential for the link fields has translational invariance, broken only by boundary effects that trigger an exponential profile of vacuum expectation values. The spectrum of physical states deviates exponentially from that of the continuum for large masses; we discuss the effects of such exponential towers on gauge coupling unification. We also present a supersymmetric example in which a warp factor is driven by Fayet-Iliopoulos terms. The model is peculiar in that it possesses a global supersymmetry that remains unbroken despite nonvanishing D-terms. Inclusion of gravity and/or additional messenger fields leads to the collective breaking of supersymmetry and to unusual phenomenology.Comment: 28 pages LaTeX, JHEP format, 7 eps figures (v2: reference added
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