1,358 research outputs found

    Special functions from quantum canonical transformations

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    Quantum canonical transformations are used to derive the integral representations and Kummer solutions of the confluent hypergeometric and hypergeometric equations. Integral representations of the solutions of the non-periodic three body Toda equation are also found. The derivation of these representations motivate the form of a two-dimensional generalized hypergeometric equation which contains the non-periodic Toda equation as a special case and whose solutions may be obtained by quantum canonical transformation.Comment: LaTeX, 24 pp., Imperial-TP-93-94-5 (revision: two sections added on the three-body Toda problem and a two-dimensional generalization of the hypergeometric equation

    Pengaruh Pergantian Auditor dan Kualitas Audit terhadap Opini Audit Going Concern: Studi Empiris Perusahaan Manufaktur di Bursa Efek Indonesia

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    This study aims to analyze the effect of auditor switching and audit quality on going concern audit opinion in listed manufacturing companies of the Indonesia Stock Exchange (BEI) in the year 2006 to 2008. Auditor switching was marked by a change to the Public Accountant firms (KAP) who perform the audits or companies used the services of an auditor different than before. Audit quality is proxied by the scale of the BigFour auditors or non-Big Four. Going-concern audit opinion is the explanation given by the auditor if there is any doubt regarding the ability of the company to survive in the future. This study used 70 samples out of 452 populations, using purposive sampling technique in which the main criterion is the sample company received going-concern audit opinion in the year preceding the auditor switched. Results of the study showed that the change of auditors and audit quality is not a factor in determining going concern audit opinion of the company

    Rapid TeV Gamma-Ray Flaring of BL Lacertae

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    We report on the detection of a very rapid TeV gamma-ray flare from BL Lacertae on 2011 June 28 with the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The flaring activity was observed during a 34.6 minute exposure, when the integral flux above 200 GeV reached (3.4 ± 0.6) × 10^(–6) photons m^(–2) s^(–1), roughly 125% of the Crab Nebula flux measured by VERITAS. The light curve indicates that the observations missed the rising phase of the flare but covered a significant portion of the decaying phase. The exponential decay time was determined to be 13 ± 4 minutes, making it one of the most rapid gamma-ray flares seen from a TeV blazar. The gamma-ray spectrum of BL Lacertae during the flare was soft, with a photon index of 3.6 ± 0.4, which is in agreement with the measurement made previously by MAGIC in a lower flaring state. Contemporaneous radio observations of the source with the Very Long Baseline Array revealed the emergence of a new, superluminal component from the core around the time of the TeV gamma-ray flare, accompanied by changes in the optical polarization angle. Changes in flux also appear to have occurred at optical, UV, and GeV gamma-ray wavelengths at the time of the flare, although they are difficult to quantify precisely due to sparse coverage. A strong flare was seen at radio wavelengths roughly four months later, which might be related to the gamma-ray flaring activities. We discuss the implications of these multiwavelength results

    Perancangan Visual Brand Identity Dan Promosi Depot Classic Di Surabaya

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    Depot Classic adalah sebuah depot makanan di Surabaya dengan spesialisasi bahan dasar daging ayam dan mie. Brand Awareness dari Depot Classic masih kurang tinggi, dikarenakan kurang menariknya sisi visual dari identitas yang dimiliki oleh Depot Classic serta belum adanya upaya untuk melakukan kegiatan promosi. Oleh karena itu, Depot Classic memerlukan sebuah identitas visual yang baru dan menarik sekaligus dapat menampilkan karakter dari Depot Classic. Dengan Perancangan Visual Brand Identity dan promosi ini, diharapkan brand awareness dari Depot Classic ini dapat meningkat

    Einstein and Yang-Mills theories in hyperbolic form without gauge-fixing

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    The evolution of physical and gauge degrees of freedom in the Einstein and Yang-Mills theories are separated in a gauge-invariant manner. We show that the equations of motion of these theories can always be written in flux-conservative first-order symmetric hyperbolic form. This dynamical form is ideal for global analysis, analytic approximation methods such as gauge-invariant perturbation theory, and numerical solution.Comment: 12 pages, revtex3.0, no figure

    Quantum Backreaction on ``Classical'' Variables

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    A mathematically consistent procedure for coupling quasiclassical and quantum variables through coupled Hamilton-Heisenberg equations of motion is derived from a variational principle. During evolution, the quasiclassical variables become entangled with the quantum variables with the result that the value of the quasiclassical variables depends on the quantum state. This provides a formalism to compute the backreaction of any quantum system on a quasiclassical one. In particular, it leads to a natural candidate for a theory of gravity coupled to quantized matter in which the gravitational field is not quantized.Comment: LaTeX, 10 pp. title change, minor improvement of presentatio

    Geometrical Hyperbolic Systems for General Relativity and Gauge Theories

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    The evolution equations of Einstein's theory and of Maxwell's theory---the latter used as a simple model to illustrate the former--- are written in gauge covariant first order symmetric hyperbolic form with only physically natural characteristic directions and speeds for the dynamical variables. Quantities representing gauge degrees of freedom [the spatial shift vector βi(t,xj)\beta^{i}(t,x^{j}) and the spatial scalar potential ϕ(t,xj)\phi(t,x^{j}), respectively] are not among the dynamical variables: the gauge and the physical quantities in the evolution equations are effectively decoupled. For example, the gauge quantities could be obtained as functions of (t,xj)(t,x^{j}) from subsidiary equations that are not part of the evolution equations. Propagation of certain (``radiative'') dynamical variables along the physical light cone is gauge invariant while the remaining dynamical variables are dragged along the axes orthogonal to the spacelike time slices by the propagating variables. We obtain these results by (1)(1) taking a further time derivative of the equation of motion of the canonical momentum, and (2)(2) adding a covariant spatial derivative of the momentum constraints of general relativity (Lagrange multiplier βi\beta^{i}) or of the Gauss's law constraint of electromagnetism (Lagrange multiplier ϕ\phi). General relativity also requires a harmonic time slicing condition or a specific generalization of it that brings in the Hamiltonian constraint when we pass to first order symmetric form. The dynamically propagating gravity fields straightforwardly determine the ``electric'' or ``tidal'' parts of the Riemann tensor.Comment: 24 pages, latex, no figure

    A Quantum-Classical Brackets from p-Mechanics

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    We provide an answer to the long standing problem of mixing quantum and classical dynamics within a single formalism. The construction is based on p-mechanical derivation (quant-ph/0212101, quant-ph/0304023) of quantum and classical dynamics from the representation theory of the Heisenberg group. To achieve a quantum-classical mixing we take the product of two copies of the Heisenberg group which represent two different Planck's constants. In comparison with earlier guesses our answer contains an extra term of analytical nature, which was not obtained before in purely algebraic setup. Keywords: Moyal brackets, Poisson brackets, commutator, Heisenberg group, orbit method, representation theory, Planck's constant, quantum-classical mixingComment: LaTeX, 7 pages (EPL style), no figures; v2: example of dynamics with two different Planck's constants is added, minor corrections; v3: major revion, a complete example of quantum-classic dynamics is given; v4: few grammatic correction

    Unitary Equivalence of the Metric and Holonomy Formulations of 2+1 Dimensional Quantum Gravity on the Torus

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    Recent work on canonical transformations in quantum mechanics is applied to transform between the Moncrief metric formulation and the Witten-Carlip holonomy formulation of 2+1-dimensional quantum gravity on the torus. A non-polynomial factor ordering of the classical canonical transformation between the metric and holonomy variables is constructed which preserves their classical modular transformation properties. An extension of the definition of a unitary transformation is briefly discussed and is used to find the inner product in the holonomy variables which makes the canonical transformation unitary. This defines the Hilbert space in the Witten-Carlip formulation which is unitarily equivalent to the natural Hilbert space in the Moncrief formulation. In addition, gravitational theta-states arising from ``large'' diffeomorphisms are found in the theory.Comment: 31 pages LaTeX [Important Revision: a section is added constructing the inner product/Hilbert space for the Witten-Carlip holonomy formulation; the proof of unitary equivalence of the metric and holonomy formulations is then completed. Other additions include discussion of relation of canonical and unitary transformations. Title/abstract change.

    An Information-Theoretic Measure of Uncertainty due to Quantum and Thermal Fluctuations

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    We study an information-theoretic measure of uncertainty for quantum systems. It is the Shannon information II of the phase space probability distribution \la z | \rho | z \ra , where |z \ra are coherent states, and ρ\rho is the density matrix. The uncertainty principle is expressed in this measure as I1I \ge 1. For a harmonic oscillator in a thermal state, II coincides with von Neumann entropy, - \Tr(\rho \ln \rho), in the high-temperature regime, but unlike entropy, it is non-zero at zero temperature. It therefore supplies a non-trivial measure of uncertainty due to both quantum and thermal fluctuations. We study II as a function of time for a class of non-equilibrium quantum systems consisting of a distinguished system coupled to a heat bath. We derive an evolution equation for II. For the harmonic oscillator, in the Fokker-Planck regime, we show that II increases monotonically. For more general Hamiltonians, II settles down to monotonic increase in the long run, but may suffer an initial decrease for certain initial states that undergo ``reassembly'' (the opposite of quantum spreading). Our main result is to prove, for linear systems, that II at each moment of time has a lower bound ItminI_t^{min}, over all possible initial states. This bound is a generalization of the uncertainty principle to include thermal fluctuations in non-equilibrium systems, and represents the least amount of uncertainty the system must suffer after evolution in the presence of an environment for time tt.Comment: 36 pages (revised uncorrupted version), Report IC 92-93/2
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