12,055 research outputs found
Limit solutions of the Chern-Simons equation
We investigate the scalar Chern-Simons equation in cases where there is no solution for a given nonnegative finite measure
. Approximating by a sequence of nonnegative functions or
finite measures for which this equation has a solution, we show that the
sequence of solutions of the Dirichlet problem converges to the solution with
largest possible datum \mu^# \le \mu and we derive an explicit formula of
\mu^# in terms of . The counterpart for the Chern-Simons system with
datum behaves differently and the conclusion depends on how much
the measures and charge singletons
Wave-like Solutions for Bianchi type-I cosmologies in 5D
We derive exact solutions to the vacuum Einstein field equations in 5D, under
the assumption that (i) the line element in 5D possesses self-similar symmetry,
in the classical understanding of Sedov, Taub and Zeldovich, and that (ii) the
metric tensor is diagonal and independent of the coordinates for ordinary 3D
space. These assumptions lead to three different types of self-similarity in
5D: homothetic, conformal and "wave-like". In this work we present the most
general wave-like solutions to the 5D field equations. Using the standard
technique based on Campbell's theorem, they generate a large number of
anisotropic cosmological models of Bianchi type-I, which can be applied to our
universe after the big-bang, when anisotropies could have played an important
role. We present a complete review of all possible cases of self-similar
anisotropic cosmologies in 5D. Our analysis extends a number of previous
studies on wave-like solutions in 5D with spatial spherical symmetry
Barriers to Diversification and Regional Allocation of Capital
In order to evaluate the allocational effectiveness of regional policy when harmonizing regional economic conditions firms? preferences play a pivot role. If harmonization hinders risk diversification of the firm, then instead of regional diversification of capital agglomeration of capital occurs. Hence, regional policy will not achieve its objective to equal the spatial allocation of capital. --Regional policy,agglomeration,diversification,allocation,risk aversion,prudence
A framework for closed-loop supply chains of reusable articles
Reuse practices contribute to the environmental and economical sustainability of production and distribution systems. Surprisingly, reuse closed-loop supply chains (CLSC) have not been widely researched for the moment. In this paper, we explore the scientific literature on reuse and we propose a framework for reusable articles. This conceptual structure includes a typology integrating under the reusable articles term different categories of articles (transportation items, packaging materials, tools) and addresses the management issues that arise in reuse CLSC. We ground our results in a set of case studies developed in real industrial settings, which have also been contrasted with cases available in existing literature.reverse logistics;case studies;closed-loop supply chains;returns managment
The Hardy Uncertainty Principle Revisited
We give a real-variable proof of the Hardy uncertainty principle. The method
is based on energy estimates for evolutions with positive viscosity, convexity
properties of free waves with Gaussian decay at two different times, elliptic
-estimates and the invertibility of the Fourier transform on L^2(\Rn)
and \mathcal S'(\Rn)
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