23,579 research outputs found

    Self Interference of Single Electrodynamic Particle in Double Slit

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    It is by the long established fact in experiment and theory that electromagnetic waves, here as one component of an IED particle, passing a double slit will undergo self inference each, producing at a detector plane fringed intensities. The wave generating point charge of a zero rest mass, as the other component of the particle, is maintained a constant energy and speed by a repeated radiation reabsorption/reemission scheme, and in turn steered in direction in its linear motion by the reflected radiation field, and will thereby travel to the detector along (one of) the optical path(s) of the waves leading to a bright interference fringe. We elucidate the process formally based on first principles solutions for the IED particle and known principles for wave-matter interaction.Comment: Presentation at The 6th Int. Symp. Quantum Theory and Symmetries, Univ. Kent, 2009

    The Five-Loop Four-Point Amplitude of N=4 super-Yang-Mills Theory

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    Using the method of maximal cuts, we construct the complete D-dimensional integrand of the five-loop four-point amplitude of N = 4 super-Yang-Mills theory, including nonplanar contributions. In the critical dimension where this amplitude becomes ultraviolet divergent, we present a compact explicit expression for the nonvanishing ultraviolet divergence in terms of three vacuum integrals. This construction provides a crucial step towards obtaining the corresponding amplitude of N = 8 supergravity useful for resolving the general ultraviolet behavior of supergravity theories.Comment: 5 pages, 4 figures, RevTex. Ancillary file included. v2 minor corrections, corrected references and overall phase in eq. (5), matching journal versio

    Application of the Exact Muffin-Tin Orbitals Theory: the Spherical Cell Approximation

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    We present a self-consistent electronic structure calculation method based on the {\it Exact Muffin-Tin Orbitals} (EMTO) Theory developed by O. K. Andersen, O. Jepsen and G. Krier (in {\it Lectures on Methods of Electronic Structure Calculations}, Ed. by V. Kumar, O.K. Andersen, A. Mookerjee, Word Scientific, 1994 pp. 63-124) and O. K. Andersen, C. Arcangeli, R. W. Tank, T. Saha-Dasgupta, G. Krier, O. Jepsen, and I. Dasgupta, (in {\it Mat. Res. Soc. Symp. Proc.} {\bf 491}, 1998 pp. 3-34). The EMTO Theory can be considered as an {\it improved screened} KKR (Korringa-Kohn-Rostoker) method which is able to treat large overlapping potential spheres. Within the present implementation of the EMTO Theory the one electron equations are solved exactly using the Green's function formalism, and the Poisson's equation is solved within the {\it Spherical Cell Approximation} (SCA). To demonstrate the accuracy of the SCA-EMTO method test calculations have been carried out.Comment: 20 pages, 10 figure

    Farmers' perceptions of the lay health worker on farms in the Western Cape, South Africa

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    This study is focussed on farms situated in the Boland health district of the Cape Winelands, South Africa. The aim was to explore, understand, and describe the perceptions of farmers of having a trained lay health worker (LHW) on the farm. A qualitative study design was applied. Data were collected during six in-depth interviews and two focus group discussions with participating farmers. The results show that farmers remained positive about the concept of having a trained LHW on the farm, but became frustrated with the lack of recognition of their and the LHWs' contribution by the public health service. Farmers who are willing to participate and remain active are key to introducing a farm community-based LHW intervention. Sustainable LHW interventions are dependent on public health sector support and recognition of all role players.Farm Management,

    Two-Electron Photon Emission From Metallic Quantum Wells

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    Unusual emission of visible light is observed in scanning tunneling microscopy of the quantum well system Na on Cu(111). Photons are emitted at energies exceeding the energy of the tunneling electrons. Model calculations of two-electron processes which lead to quantum well transitions reproduce the experimental fluorescence spectra, the quantum yield, and the power-law variation of the intensity with the excitation current.Comment: revised version, as published; 4 pages, 3 figure

    Internally Electrodynamic Particle Model: Its Experimental Basis and Its Predictions

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    The internally electrodynamic (IED) particle model was derived based on overall experimental observations, with the IED process itself being built directly on three experimental facts, a) electric charges present with all material particles, b) an accelerated charge generates electromagnetic waves according to Maxwell's equations and Planck energy equation and c) source motion produces Doppler effect. A set of well-known basic particle equations and properties become predictable based on first principles solutions for the IED process; several key solutions achieved are outlined, including the de Broglie phase wave, de Broglie relations, Schr\"odinger equation, mass, Einstein mass-energy relation, Newton's law of gravity, single particle self interference, and electromagnetic radiation and absorption; these equations and properties have long been broadly experimentally validated or demonstrated. A specific solution also predicts the Doebner-Goldin equation which emerges to represent a form of long-sought quantum wave equation including gravity. A critical review of the key experiments is given which suggests that the IED process underlies the basic particle equations and properties not just sufficiently but also necessarily.Comment: Presentation at the 27th Int Colloq on Group Theo Meth in Phys, 200

    Edge scaling limits for a family of non-Hermitian random matrix ensembles

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    A family of random matrix ensembles interpolating between the GUE and the Ginibre ensemble of n×nn\times n matrices with iid centered complex Gaussian entries is considered. The asymptotic spectral distribution in these models is uniform in an ellipse in the complex plane, which collapses to an interval of the real line as the degree of non-Hermiticity diminishes. Scaling limit theorems are proven for the eigenvalue point process at the rightmost edge of the spectrum, and it is shown that a non-trivial transition occurs between Poisson and Airy point process statistics when the ratio of the axes of the supporting ellipse is of order n1/3n^{-1/3}. In this regime, the family of limiting probability distributions of the maximum of the real parts of the eigenvalues interpolates between the Gumbel and Tracy-Widom distributions.Comment: 44 page
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