Pseudo-differential Operators with Semi-Quasielliptic Symbols Over p-adic Fields

In this article, we study pseudo-differential equations involving semi-quasielliptic symbols over p-adics. We determine the function spaces where such equations have solutions. We introduce the space of infinitely pseudo-differentiable functions with respect to a semi-quasielliptic operator. By using these spaces we show the existence of a regularization effect for certain parabolic equations over p-adics.Comment: Accepted in Journal of Mathemaatical Analysis and its Application

Second thoughts on second moments : panel evidence on asset-based models of currency crises

The literature on speculative attacks has been given new impetus by the collapse of the European currency arrangements beginning in 1992, by the Mexican peso crisis and after-effects in 1994, and most recently by speculative attacks across Asia. One stand of this literature stresses the importance of imbalances in stocks of monetary and financial aggregates rather than traditional"flow"factors, arguing that massive, volatile capital flows have become a dominant feature of the global landscape, and that exchange-rate levels and current accounts have not proved convincing as proximate causes of crises. The authors test two popular asset-based models of speculative attacks -- Krugman and Rotemberg (1992) and Calvo and Mendoza (1995) -- especially their emphasis on the second moments of monetary aggregates. Analyzing monthly panels of appropriate countries in three regions, they find evidence for the importance of money/reserve ratios predicted by both models, and their variance as predicted by Calvo and Mendoza. But the variance of velocity does not appear to be important, casting some doubt on the Krugman-Rotemberg target zone framework and the interpretation of the Calvo-Mendoza results.Fiscal&Monetary Policy,Payment Systems&Infrastructure,Environmental Economics&Policies,Insurance&Risk Mitigation,Economic Theory&Research,Economic Theory&Research,Fiscal&Monetary Policy,Macroeconomic Management,Environmental Economics&Policies,Economic Stabilization

Molecular dynamics simulations of complex shaped particles using Minkowski operators

The Minkowski operators (addition and substraction of sets in vectorial spaces) has been extensively used for Computer Graphics and Image Processing to represent complex shapes. Here we propose to apply those mathematical concepts to extend the Molecular Dynamics (MD) Methods for simulations with complex-shaped particles. A new concept of Voronoi-Minkowski diagrams is introduced to generate random packings of complex-shaped particles with tunable particle roundness. By extending the classical concept of Verlet list we achieve numerical efficiencies that do not grow quadratically with the body number of sides. Simulations of dissipative granular materials under shear demonstrate that the method complies with the first law of thermodynamics for energy balance.Comment: Submitted to Phys. Rev.

Quasi-isotropic spacecraft antenna system Final report

Spacecraft quasi-isotropic antenna system for space telemetr