2,288 research outputs found

    Gauge Independence and Relativistic Electron Dispersion Equation in Dense Media

    Get PDF
    We discuss the gauge parameter dependence of particle spectra in statistical quantum electrodynamics and conclude that the electron spectrum is gauge-parameter dependent. The physical spectrum being obtained in the Landau gauge, which leads to gauge invariance in a restricted class of gauge transformations.Comment: Style corrections 16 pages, three figures, RevTe

    On the Significance of the Quantity "A Squared"

    Full text link
    We consider the gauge potential A and argue that the minimum value of the volume integral of A squared (in Euclidean space) may have physical meaning, particularly in connection with the existence of topological structures. A lattice simulation comparing compact and non-compact ``photodynamics'' shows a jump in this quantity at the phase transition, supporting this idea.Comment: 6 pages, one figur

    Entrepreneurship Education’s Impact on Entrepreneurial Intention: A Predictive Regression Model of Chinese University Students

    Full text link
    “Entrepreneurship education’s impact on entrepreneurial intention: A predictive regression model of Chinese university students” is a dissertation study by Brian A. Lavelle, doctoral candidate at George Fox University. The study investigates the impact of entrepreneurship education on entrepreneurial intention using quantitative methods and survey data from China. The study uses Ajzen’s (1991) Theory of Planned Behavior and the Entrepreneurial Intention Questionnaire (Linan & Chen, 2009) to investigate the impact between personal attitude, subjective norms, perceived behavioral control, and entrepreneurship education on entrepreneurial intention. The data was collected from eleven college and university programs in Wuxi, Jiangsu Province, in the People’s Republic of China. The primary methodology of the study was regression analysis which allowed the researcher to assess the individual impact of each antecedent factor in the regression model. The findings of the study provide no evidence that entrepreneurship education positively impacts entrepreneurial intention in China. The author concludes that the self-selection bias and differences between ranked universities and vocational colleges in China may explain the results of the study. This research provides findings with implications to university communities and policy-makers in China, which may serve as a performance measurement of entrepreneurship education policies. This research provides findings with implications to scholars as the entrepreneurship education-entrepreneurial relationship in China is currently inconclusive

    Concurrent optimization of airframe and engine design parameters

    Get PDF
    An integrated system for the multidisciplinary analysis and optimization of airframe and propulsion design parameters is being developed. This system is known as IPAS, the Integrated Propulsion/Airframe Analysis System. The traditional method of analysis is one in which the propulsion system analysis is loosely coupled to the overall mission performance analysis. This results in a time consuming iterative process. First, the engine is designed and analyzed. Then, the results from this analysis are used in a mission analysis to determine the overall aircraft performance. The results from the mission analysis are used as a guide as the engine is redesigned and the entire process repeated. In IPAS, the propulsion system, airframe, and mission are closely coupled. The propulsion system analysis code is directly integrated into the mission analysis code. This allows the propulsion design parameters to be optimized along with the airframe and mission design parameters, significantly reducing the time required to obtain an optimized solution

    Quantumness in decoherent quantum walk using measurement-induced disturbance

    Full text link
    The classicalization of a decoherent discrete-time quantum walk on a line or an n-cycle can be demonstrated in various ways that do not necessarily provide a geometry-independent description. For example, the position probability distribution becomes increasingly Gaussian, with a concomitant fall in the standard deviation, in the former case, but not in the latter. As another example, each step of the quantum walk on a line may be subjected to an arbitrary phase gate, without affecting the position probability distribution, no matter whether the walk is noiseless or noisy. This symmetry, which is absent in the case of noiseless cyclic walk, but is restored in the presence of sufficient noise, serves as an indicator of classicalization, but only in the cyclic case. Here we show that the degree of quantum correlations between the coin and position degrees of freedom, quantified by a measure based on the disturbance induced by local measurements (Luo, Phys. Rev. A 77, 022301 (2008)), provides a suitable measure of classicalization across both type of walks. Applying this measure to compare the two walks, we find that cyclic quantum walks tend to classicalize faster than quantum walks on a line because of more efficient phase randomization due to the self-interference of the two counter-rotating waves. We model noise as acting on the coin, and given by the squeezed generalized amplitude damping (SGAD) channel, which generalizes the generalized amplitude damping channel.Comment: 8 pages with 8 figures, Published versio

    Gluon condensate, quark propagation, and dilepton production in the quark-gluon plasma

    Get PDF
    A calculation of the thermal quark propagator is presented taking the gluon condensate above the critical temperature into account. The quark dispersion relation and the dilepton production following from this propagator are derived.Comment: 4 pages, LATEX (style file included), 3 PostScript figures, to be published in the proceedings of the Quark Matter'99 conferenc
    corecore