37,972 research outputs found

    A new model for the double well potential

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    A new model for the double well potential is presented in the paper. In the new potential, the exchanging rate could be easily calculated by the perturbation method in supersymmetric quantum mechanics. It gives good results whether the barrier is high or sallow. The new model have many merits and may be used in the double well problem.Comment: 3pages, 3figure

    Ricci flow on K\"ahler-Einstein manifolds

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    In our previous paper math.DG/0010008, we develop some new techniques in attacking the convergence problems for the K\"ahler Ricci flow. The one of main ideas is to find a set of new functionals on curvature tensors such that the Ricci flow is the gradient like flow of these functionals. We successfully find such functionals in case of Kaehler manifolds. On K\"ahler-Einstein manifold with positive scalar curvature, if the initial metric has positive bisectional curvature, we prove that these functionals have a uniform lower bound, via the effective use of Tian's inequality. Consequently, we prove the following theorem: Let MM be a K\"ahler-Einstein manifold with positive scalar curvature. If the initial metric has nonnegative bisectional curvature and positive at least at one point, then the K\"ahler Ricci flow will converge exponentially fast to a K\"ahler-Einstein metric with constant bisectional curvature. Such a result holds for K\"ahler-Einstein orbifolds.Comment: 49 pages. This is a revised version. Sections 4 and 5 are simplified and streamline

    Calabi-Yau manifolds from pairs of non-compact Calabi-Yau manifolds

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    Most of Calabi-Yau manifolds that have been considered by physicists are complete intersection Calabi-Yau manifolds of toric varieties or some quotients of product types. Purpose of this paper is to introduce a different and rather new kind of construction method of Calabi-Yau manifolds by pasting two non-compact Calabi-Yau manifolds. We will also in some details explain a curious and mysterious similarity with construction of some G2G_2-manifolds (also called Joyce manifolds), which are base spaces for M-theory.Comment: 10 pages. Accepted for publication in JHE

    Growth of the Internet and the Establishment of Proper Digital Copyright Strategies: China as a Case Study

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    With the dramatic development of Information Communication Technology (ICT), the Internet is playing an increasingly significant role in our society. The growth of the Internet not only greatly enhances the development ofElectronic Commence (EC) and an Internet economy, but also speeds up the steps of globalizarion' and the formation of the "global village." Ever-improving Internet technology changes the traditional rules of distribution and dissemination of information and copyright works," and enables users to efficiently access and disseminate online copyright works
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