37,972 research outputs found
A new model for the double well potential
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
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 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
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 -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
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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