220,399 research outputs found

    Coupled oscillators and Feynman's three papers

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    According to Richard Feynman, the adventure of our science of physics is a perpetual attempt to recognize that the different aspects of nature are really different aspects of the same thing. It is therefore interesting to combine some, if not all, of Feynman's papers into one. The first of his three papers is on the ``rest of the universe'' contained in his 1972 book on statistical mechanics. The second idea is Feynman's parton picture which he presented in 1969 at the Stony Brook conference on high-energy physics. The third idea is contained in the 1971 paper he published with his students, where they show that the hadronic spectra on Regge trajectories are manifestations of harmonic-oscillator degeneracies. In this report, we formulate these three ideas using the mathematics of two coupled oscillators. It is shown that the idea of entanglement is contained in his rest of the universe, and can be extended to a space-time entanglement. It is shown also that his parton model and the static quark model can be combined into one Lorentz-covariant entity. Furthermore, Einstein's special relativity, based on the Lorentz group, can also be formulated within the mathematical framework of two coupled oscillators.Comment: 31 pages, 6 figures, based on the concluding talk at the 3rd Feynman Festival (Collage Park, Maryland, U.S.A., August 2006), minor correction

    Ulrich line bundles on Enriques surfaces with a polarization of degree four

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    In this paper, we prove the existence of an Enriques surface with a polarization of degree four with an Ulrich bundle of rank one. As a consequence, we prove that general polarized Enriques surfaces of degree four, with the same numerical polarization class, carry Ulrich line bundles.Comment: to appear in a volume of Ann. Univ. Ferrara dedicated to the memory of Alexandru Lasc

    Density of Yang-Lee zeros for the Ising ferromagnet

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    The densities of Yang-Lee zeros for the Ising ferromagnet on the L×LL\times L square lattice are evaluated from the exact grand partition functions (L=316L=3\sim16). The properties of the density of Yang-Lee zeros are discussed as a function of temperature TT and system size LL. The three different classes of phase transitions for the Ising ferromagnet, first-order phase transition, second-order phase transition, and Yang-Lee edge singularity, are clearly distinguished by estimating the magnetic scaling exponent yhy_h from the densities of zeros for finite-size systems. The divergence of the density of zeros at Yang-Lee edge in high temperatures (Yang-Lee edge singularity), which has been detected only by the series expansion until now for the square-lattice Ising ferromagnet, is obtained from the finite-size data. The identification of the orders of phase transitions in small systems is also discussed using the density of Yang-Lee zeros.Comment: to appear in Physical Review

    Standing waves in the Lorentz-covariant world

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    When Einstein formulated his special relativity, he developed his dynamics for point particles. Of course, many valiant efforts have been made to extend his relativity to rigid bodies, but this subject is forgotten in history. This is largely because of the emergence of quantum mechanics with wave-particle duality. Instead of Lorentz-boosting rigid bodies, we now boost waves and have to deal with Lorentz transformations of waves. We now have some understanding of plane waves or running waves in the covariant picture, but we do not yet have a clear picture of standing waves. In this report, we show that there is one set of standing waves which can be Lorentz-transformed while being consistent with all physical principle of quantum mechanics and relativity. It is possible to construct a representation of the Poincar\'e group using harmonic oscillator wave functions satisfying space-time boundary conditions. This set of wave functions is capable of explaining the quantum bound state for both slow and fast hadrons. In particular it can explain the quark model for hadrons at rest, and Feynman's parton model hadrons moving with a speed close to that of light.Comment: LaTex 20 pages, presented at the 2004 meeting of the International Association of Relativistic Dynamincs, to be published in the proceeding

    Feynman's Decoherence

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    Gell-Mann's quarks are coherent particles confined within a hadron at rest, but Feynman's partons are incoherent particles which constitute a hadron moving with a velocity close to that of light. It is widely believed that the quark model and the parton model are two different manifestations of the same covariant entity. If this is the case, the question arises whether the Lorentz boost destroys coherence. It is pointed out that this is not the case, and it is possible to resolve this puzzle without inventing new physics. It is shown that this decoherence is due to the measurement processes which are less than complete.Comment: RevTex 15 pages including 6 figs, presented at the 9th Int'l Conference on Quantum Optics (Raubichi, Belarus, May 2002), to be published in the proceeding

    Designing an automated prototype tool for preservation quality metadata extraction for ingest into digital repository

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    We present a viable framework for the automated extraction of preservation quality metadata, which is adjusted to meet the needs of, ingest to digital repositories. It has three distinctive features: wide coverage, specialisation and emphasis on quality. Wide coverage is achieved through the use of a distributed system of tool repositories, which helps to implement it over a broad range of document object types. Specialisation is maintained through the selection of the most appropriate metadata extraction tool for each case based on the identification of the digital object genre. And quality is sustained by introducing control points at selected stages of the workflow of the system. The integration of these three features as components in the ingest of material into digital repositories is a defining step ahead in the current quest for improved management of digital resources

    Generalized BFT Formalism of Electroweak Theory in the Unitary Gauge

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    We systematically embed the SU(2)×\timesU(1) Higgs model in the unitary gauge into a fully gauge-invariant theory by following the generalized BFT formalism. We also suggest a novel path to get a first-class Lagrangian directly from the original second-class one using the BFT fields.Comment: 14 pages, Latex, no figure
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