3,650 research outputs found

    Quantum resolution of black hole singularities

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    We study the classical and quantum theory of spherically symmetric spacetimes with scalar field coupling in general relativity. We utilise the canonical formalism of geometrodynamics adapted to the Painleve-Gullstrand coordinates, and present a new quantisation of the resulting field theory. We give an explicit construction of operators that capture curvature properties of the spacetime and use these to show that the black hole curvature singularity is avoided in the quantum theory.Comment: 5 pages, version to appear in CQ

    Efektivitas Promotion Mix terhadap Keputusan Wali Murid Memilih SMA IT Pesantren Nururrahman

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    This research aim was to obtain empirical evidence and analyzing the effectiveness of promotional mix on decision parents in choosing a school. The research type was causality using survey approach. The population of this research was candidate parents who purchased the form registering student new admission (PPDB) in school year of 2016/2017 as many as 217 people. The number of samples was counted 69 peoples. Data was collected through observation and questionnaire-based. The data analysis method used structural equation model based on regression variance with partial least square approach. The results of this research indicated that only word-of mouth marketing components of promotional mix had significant effect to the decision parent. Promotional mix was started from advertising to establish brand awareness, public relations and direct marketing activities to shape consumer behavior, the role of word-of mouth marketing and terminate in personal selling activities to determine purchase decisions

    Understanding Determinants and Common Factors of Railway and Sovereign Securities during the First Era of Globalisation

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    General covariance, and supersymmetry without supersymmetry

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    An unusual four-dimensional generally covariant and supersymmetric SU(2) gauge theory is described. The theory has propagating degrees of freedom, and is invariant under a local (left-handed) chiral supersymmetry, which is half the supersymmetry of supergravity. The Hamiltonian 3+1 decomposition of the theory reveals the remarkable feature that the local supersymmetry is a consequence of Yang-Mills symmetry, in a manner reminiscent of how general coordinate invariance in Chern-Simons theory is a consequence of Yang-Mills symmetry. It is possible to write down an infinite number of conserved currents, which strongly suggests that the theory is classically integrable. A possible scheme for non-perturbative quantization is outlined. This utilizes ideas that have been developed and applied recently to the problem of quantizing gravity.Comment: 17 pages, RevTeX, two minor errors correcte

    Two dimensional general covariance from three dimensions

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    A 3d generally covariant field theory having some unusual properties is described. The theory has a degenerate 3-metric which effectively makes it a 2d field theory in disguise. For 2-manifolds without boundary, it has an infinite number of conserved charges that are associated with graphs in two dimensions and the Poisson algebra of the charges is closed. For 2-manifolds with boundary there are additional observables that have a Kac-Moody Poisson algebra. It is further shown that the theory is classically integrable and the general solution of the equations of motion is given. The quantum theory is described using Dirac quantization, and it is shown that there are quantum states associated with graphs in two dimensions.Comment: 10 pages (Latex), Alberta-Thy-19-9

    On Singularity Resolution in Quantum Gravity

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    We examine the singularity resolution issue in quantum gravity by studying a new quantization of standard Friedmann-Robertson-Walker geometrodynamics. The quantization procedure is inspired by the loop quantum gravity programme, and is based on an alternative to the Schr\"odinger representation normally used in metric variable quantum cosmology. We show that in this representation for quantum geometrodynamics there exists a densely defined inverse scale factor operator, and that the Hamiltonian constraint acts as a difference operator on the basis states. We find that the cosmological singularity is avoided in the quantum dynamics. We discuss these results with a view to identifying the criteria that constitute "singularity resolution" in quantum gravity.Comment: 12 page

    Solutions in Self-Dual Gravity Constructed Via Chiral Equations

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    The chiral model for self-dual gravity given by Husain in the context of the chiral equations approach is discussed. A Lie algebra corresponding to a finite dimensional subgroup of the group of symplectic diffeomorphisms is found, and then use for expanding the Lie algebra valued connections associated with the chiral model. The self-dual metric can be explicitly given in terms of harmonic maps and in terms of a basis of this subalgebra.Comment: Plain Latex, 13 Pages, major revisions of style in the above proof, several Comments added. Version to appear in Physical Review

    An Investigation of the Effects of Categorization and Discrimination Training on Auditory Perceptual Space

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    Psychophysical phenomena such as categorical perception and the perceptual magnet effect indicate that our auditory perceptual spaces are warped for some stimuli. This paper investigates the effects of two different kinds of training on auditory perceptual space. It is first shown that categorization training, in which subjects learn to identify stimuli within a particular frequency range as members of the same category, can lead to a decrease in sensitivity to stimuli in that category. This phenomenon is an example of acquired similarity and apparently has not been previously demonstrated for a category-relevant dimension. Discrimination training with the same set of stimuli was shown to have the opposite effect: subjects became more sensitive to differences in the stimuli presented during training. Further experiments investigated some of the conditions that are necessary to generate the acquired similarity found in the first experiment. The results of these experiments are used to evaluate two neural network models of the perceptual magnet effect. These models, in combination with our experimental results, are used to generate an experimentally testable hypothesis concerning changes in the brain's auditory maps under different training conditions.Alfred P. Sloan Foundation and the National institutes of Deafness and other Communication Disorders (R29 02852); Air Force Office of Scientific Research (F49620-98-1-0108

    Praktik Manajemen Laba: Studi Komparasi pada Perusahaan-Perusahaan yang Melakukan IPO Tahun 2012-2016

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    This research was aimed to obtain empirical evidence about the practice of earnings management between companies in manufacturing industry and financial sectors listed in Indonesian Stock Exchange. This study adopted measurement of earnings management based on conditional revenue model approach. The population in this research was 41 manufacturing companies and financial sectors listed in Indonesian Stock Exchange to conduct an initial public offerings (IPO) in 2012-2016. The sampling technique was purposive method. The sample in this research establishment was 16 manufacturing industry and 22 financial sectors companies. The data analysis method using independent-samples t test, did the normality and homogenity test previously and hypothesis testing with mann-whitney test approach. The hypothesis testing results indicated that there is no significant difference between manufacturing industry and financial sectors who conduct an IPO in 2012-2016 to the practice of earnings management

    Stalling HIV through social marketing: prospects in Pakistan

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    Over the last two decades HIV/AIDS has evolved from a series of interesting case-reports to a growing epidemic that threatens the entire world. It is feared to cause devastation among large pockets of populations and may roll back more than thirty years of public health achievements. This killer disease has been more amenable to behavioral change than by provision of curative services and attempts are being made to educate the public about this threat. Various techniques of promotion have been tried through out the world including television dramas/soaps, mass media and school curricula. Social marketing is an evolving strategy used to influence human behavior and choices. By using the principles of marketing and promoting behavior as a product, social marketers attempt to understand the dynamics of human behaviour and devise messages and products to change, modify, accept or reject unsafe behaviors or practices. Thus, social marketers provide an effective force to combat the spread of HIV and may serve to be invaluable allies in health promotion efforts. In a complex and diversified cultural milieu of Pakistan, social marketing can have a significant impact on health determinants and the conditions that will facilitate the adoption of health-oriented behaviors and practices. This paper gives an account of the elements needed for the success of a health promotion strategy adopted in a developing country and makes a case for social marketing to be adopted as the lead strategy for stalling HIV/AIDS in Pakistan
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