5,980 research outputs found

    The Future of California Transportation Revenue

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    Stable, predictable, and adequate transportation revenues are needed if California is to plan and deliver an excellent transportation system. This report provides a brief history of transportation revenue policies and potential futures in California. It then presents projections of transportation revenue under the recently enacted Senate Bill 1, the Road Repair and Accountability Act of 2017. Those revenue projections are compared with projections of revenue should SB 1 be repealed by voters in the November 2018 election. State-generated transportation revenues will be higher under SB1 than if the act is repealed. For 2020, the mean projection is that the state will collect 10.4billionwithSB1inplaceand10.4 billion with SB1 in place and 6.6 billion without it, a difference of 3.8billion.Overtime,changesinfueleconomyandotherfactorswillchangeannualrevenueBy2040,themeanprojectionisthatthestatewillcollect3.8 billion. Over time, changes in fuel economy and other factors will change annual revenue By 2040, the mean projection is that the state will collect 8.6 billion with SB1 and 3.4billionwithoutit,a3.4 billion without it, a 5.2 billion difference. The total of all state transportation revenue collected between 2018 and 2040, assuming no other revisions to transportation revenue programs during these years, will be about $100 billion less if SB 1 is repealed than if the law is retained. The final section of the report addresses public attitudes toward transportation tax and fee policies, since future any policy changes must be informed by public willingness to consider revenue increases and opinions about which taxes or fees would be most appropriate

    Calculation of the two-photon decay width of the f_0(980) scalar meson

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    The applicability of the quasi-static approximation for calculating the two-photon annihilation rate of the scalar f_0(980) meson envisaged as a K\bar K molecule is critically re-examined. It is shown that the validity of this approximation depends on the detailed interplay between the momentum dependence of the annihilation amplitude and the momentum transform of the bound state wave function of the annihilating pair. The approximation becomes invalid when these two scales of variation are similar. An improved method of calculation based on the inclusion of electromagnetic corrections to the kernel of the Bethe-Salpeter equation for the interacting K\bar K pair is outlined to cover this case and applied to re-evaluate the two-photon decay width for f_0(980) in a one boson exchange model for the interkaon interaction. The corrections are significant and result in a much better agreement with experiment.Comment: 14 pages, 3 figures. Fig.3 replaced. Additional remarks with reference

    The Poisson structure of the mean-field equations in the Phi^4 theory

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    We show that the mean-field time dependent equations in the Phi^4 theory can be put into a classical non-canonical hamiltonian framework with a Poisson structure which is a generalization of the standard Poisson bracket. The Heisenberg invariant appears as a structural invariant of the Poisson tensor. (To be pubished in Annals of Physics)Comment: 12 pages Te

    The Impact of ZEV Adoption on California Transportation Revenue

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    Former California Governor Jerry Brown set an ambitious target for the state to reach five million zero-emission vehicles (ZEVs) by 2030. The policy is intended to reduce greenhouse gas emissions, but progress toward this target will also affect future state-generated transportation revenues collected from vehicle owners and operators. A central concern for policymakers is to estimate the magnitude of the revenue impact. We used a simple spreadsheet model to project future transportation revenue in California through 2040 under two scenarios. The first scenario assumes that ZEV ownership continues at its historical rate of net increase, approximately 26,000 vehicles per year (the “low-adoption scenario”). The second scenario assumes that California reaches its goal of five million ZEVs by 2030 (the “high-adoption scenario”). The projections are for light duty vehicles and do not address the possibility that heavy trucks may over time also adopt alternative fuels

    Symmetry groupoids and patterns of synchrony in coupled cell networks

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    A coupled cell system is a network of dynamical systems, or “cells,” coupled together. Such systems can be represented schematically by a directed graph whose nodes correspond to cells and whose edges represent couplings. A symmetry of a coupled cell system is a permutation of the cells that preserves all internal dynamics and all couplings. Symmetry can lead to patterns of synchronized cells, rotating waves, multirhythms, and synchronized chaos. We ask whether symmetry is the only mechanism that can create such states in a coupled cell system and show that it is not. The key idea is to replace the symmetry group by the symmetry groupoid, which encodes information about the input sets of cells. (The input set of a cell consists of that cell and all cells connected to that cell.) The admissible vector fields for a given graph—the dynamical systems with the corresponding internal dynamics and couplings—are precisely those that are equivariant under the symmetry groupoid. A pattern of synchrony is “robust” if it arises for all admissible vector fields. The first main result shows that robust patterns of synchrony (invariance of “polydiagonal” subspaces under all admissible vector fields) are equivalent to the combinatorial condition that an equivalence relation on cells is “balanced.” The second main result shows that admissible vector fields restricted to polydiagonal subspaces are themselves admissible vector fields for a new coupled cell network, the “quotient network.” The existence of quotient networks has surprising implications for synchronous dynamics in coupled cell systems

    Many-body theory interpretation of deep inelastic scattering

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    We analyze data on deep inelastic scattering of electrons from the proton using ideas from standard many-body theory involving {\em bound} constituents subject to {\em interactions}. This leads us to expect, at large three-momentum transfer q{\bf{q}}, scaling in terms of the variable y~=νq\tilde{y}=\nu-{\bf |q|}. The response at constant q{\bf |q|} scales well in this variable. Interaction effects are manifestly displayed in this approach. They are illustrated in two examples.Comment: 10 pages, 4 figure

    Decay of kaonium in a chiral approach

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    The decay of the K+K- hadronic atom kaonium is investigated non-perturbatively using meson-meson interaction amplitudes taken from leading order chiral perturbation theory in an approach adapted from that proposed by Oller and Oset [18]. The Kudryavtsev-Popov eigenvalue equation is solved numerically for the energy shift and decay width due to strong interactions in the 1s state. These calculations introduce a cutoff ~ 1.4 GeV in O(4) momentum space that is necessary to regulate divergent loop contributions to the meson-meson scattering amplitudes in the strong-interaction sector. One finds lifetimes of 2.2 \pm 0.9 x 10-18s for the ground state of kaonium.Comment: 10 pages, 2 figures. Added new reference to isospin-breaking of scattering lengt

    Quasi-nuclear and quark model baryonium: historical survey

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    We review ideas and speculations concerning possible bound states or resonances coupled to the nucleon-antinucleon channel.Comment: 7 pages, no figure, Latex with espcrc2.sty, Talk at QCD99, Montpellier, France, July 1999, to appear in the Proceedings, ed. S. Nariso

    Traces for star products on the dual of a Lie algebra

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    In this paper, we describe all traces for the BCH star-product on the dual of a Lie algebra. First we show by an elementary argument that the BCH as well as the Kontsevich star-product are strongly closed if and only if the Lie algebra is unimodular. In a next step we show that the traces of the BCH star-product are given by the \ad-invariant functionals. Particular examples are the integration over coadjoint orbits. We show that for a compact Lie group and a regular orbit one can even achieve that this integration becomes a positive trace functional. In this case we explicitly describe the corresponding GNS representation. Finally we discuss how invariant deformations on a group can be used to induce deformations of spaces where the group acts on.Comment: 18 pages, LaTeX2e. Updated reference

    Spontaneous Symmetry Breaking in Photonic Lattices: Theory and Experiment

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    We examine an example of spontaneous symmetry breaking in a double-well waveguide with a symmetric potential. The ground state of the system beyond a critical power becomes asymmetric. The effect is illustrated numerically, and quantitatively analyzed via a Galerkin truncation that clearly shows the bifurcation from a symmetric to an asymmetric steady state. This phenomenon is also demonstrated experimentally when a probe beam is launched appropriately into an optically induced photonic lattice in a photorefractive material.Comment: 4 pages, 3 figure
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