5,510 research outputs found

    New perturbative solutions of the Kerr-Newman dilatonic black hole field equations

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    This work describes new perturbative solutions to the classical, four-dimensional Kerr--Newman dilaton black hole field equations. Our solutions do not require the black hole to be slowly rotating. The unperturbed solution is taken to be the ordinary Kerr solution, and the perturbation parameter is effectively the square of the charge-to-mass ratio (Q/M)2(Q/M)^2 of the Kerr--Newman black hole. We have uncovered a new, exact conjugation (mirror) symmetry for the theory, which maps the small coupling sector to the strong coupling sector (ϕϕ\phi \to -\phi). We also calculate the gyromagnetic ratio of the black hole.Comment: Revtex, 27 page

    Statistical mechanics of Kerr-Newman dilaton black holes and the bootstrap condition

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    The Bekenstein-Hawking ``entropy'' of a Kerr-Newman dilaton black hole is computed in a perturbative expansion in the charge-to-mass ratio. The most probable configuration for a gas of such black holes is analyzed in the microcanonical formalism and it is argued that it does not satisfy the equipartition principle but a bootstrap condition. It is also suggested that the present results are further support for an interpretation of black holes as excitations of extended objects.Comment: RevTeX, 5 pages, 2 PS figures included (requires epsf), submitted to Phys. Rev. Let

    Anaerober Abbau von p-Cymen und anderen Dialkylbenzenen durch neu isolierte Bakterienarten

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    Microfield Dynamics of Black Holes

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    The microcanonical treatment of black holes as opposed to the canonical formulation is reviewed and some major differences are displayed. In particular the decay rates are compared in the two different pictures.Comment: 22 pages, 4 figures, Revtex, Minor change in forma

    Infinite average lifetime of an unstable bright state in the green fluorescent protein

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    The time evolution of the fluorescence intensity emitted by well-defined ensembles of Green Fluorescent Proteins has been studied by using a standard confocal microscope. In contrast with previous results obtained in single molecule experiments, the photo-bleaching of the ensemble is well described by a model based on Levy statistics. Moreover, this simple theoretical model allows us to obtain information about the energy-scales involved in the aging process.Comment: 4 pages, 4 figure

    A Student Inventory Simulation Evaluating Changing Demand Variation and Customer Service

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    This paper presents the pedagogy of an Excel student simulation that allows the user to change various costs and demand variation and experiment with the effects of those changes on a set of customer service levels. Unlike merely reading about inventory control and the importance of customer service, students can actually experience the results of experimenting with a variety of service levels and the effects on shortages. Track: Marketing Educatio

    Are We Really Going Green Part Three

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    This paper is a second follow-up to “Green, Part One” and “Green Part Two.” In Part One the topic of Interrupted Time Series (ITS) is used to develop a multiple regression model to predict the usage of electricity at the author’s home. In the second paper a multiple regression model is developed to predict water usage in the home. The third paper is a follow-up paper after some of the data in the second paper was found to be spurious. This third paper not only cleans up the bad data, but looks at the proper usage of ITS versus a simple dummy variable. All three papers reveal our continued effort to save the planet by using less of its natural resources. The case is presented as a tutorial for a complex and real world student case

    Extensiveness of business planning and firm survival: an examination into the drivers of success and survival for knowledge intensive start-up firms

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    A number of studies have found that writing a business plan increases the likelihood of firm survival. For instance, Liao and Gartner (2006) found that firms that completed a business plan were nearly three times more likely to launch their business than those that did not. On the contrary, other studies have found no association between writing a business plan and success. For example, Honig and Karlsson (2004) found evidence that entrepreneurs only write business plans because they are required to do so by investors, educators and advisors. While the evidence is mixed on the effectiveness of business planning, previous research has not examined individual elements of business plans. Thus, it is not clear which aspects (e.g., financial projections v. marketing strategy) of business planning are positively (or negatively) related to performance and survival. Our study addresses two main issues concerning the impact of business planning in firm survival: 1) Are surviving firms different in the extent of their business planning? 2) Which topical areas within business planning are more (or less) predictive of firm survival? To seek answers, we reconceptualize business planning along four dimensions: service/product description, marketing strategy, financial projections and organizational planning

    Ghost Busting: PT-Symmetric Interpretation of the Lee Model

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    The Lee model was introduced in the 1950s as an elementary quantum field theory in which mass, wave function, and charge renormalization could be carried out exactly. In early studies of this model it was found that there is a critical value of g^2, the square of the renormalized coupling constant, above which g_0^2, the square of the unrenormalized coupling constant, is negative. Thus, for g^2 larger than this critical value, the Hamiltonian of the Lee model becomes non-Hermitian. It was also discovered that in this non-Hermitian regime a new state appears whose norm is negative. This state is called a ghost state. It has always been assumed that in this ghost regime the Lee model is an unacceptable quantum theory because unitarity appears to be violated. However, in this regime while the Hamiltonian is not Hermitian, it does possess PT symmetry. It has recently been discovered that a non-Hermitian Hamiltonian having PT symmetry may define a quantum theory that is unitary. The proof of unitarity requires the construction of a new time-independent operator called C. In terms of C one can define a new inner product with respect to which the norms of the states in the Hilbert space are positive. Furthermore, it has been shown that time evolution in such a theory is unitary. In this paper the C operator for the Lee model in the ghost regime is constructed exactly in the V/N-theta sector. It is then shown that the ghost state has a positive norm and that the Lee model is an acceptable unitary quantum field theory for all values of g^2.Comment: 20 pages, 9 figure
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