1,275 research outputs found
Currency Crises: Is Central America Different?
In a recent paper we analyzed the determinants of currency crises in a sample of 30 high and middle income countries (Esquivel and Larrain, 1998). In this work we focus on Central America and analyze whether the determinants of currency crises in this region are different from those identified in our previous work. We conclude that they are not, and show that a small set of macroeconomic variables helps to explain the currency crises that took place in Central America between 1976 and 1996. The results of tests applied here support the empirical approach that attempts to explain currency crises by focusing on the behavior of a few macroeconomic indicators. Part of the interest of this result stems from the fact that the Central American countries had an exchange rate system markedly different from that prevailing in the economies that are usually analyzed in similar studies.
THE IMPACT OF G-3 EXCHANGE RATE VOLATILITY ON DEVELOPING COUNTRIES,
This paper describes G-3 exchange rate volatility and evaluates its impact on developing countries. The paper presents empirical evidence showing that G-3 exchange rate volatility has a robust and significantly negative impact on developing countries’ exports. A one percentage point increase in G-3 exchange rate volatility decreases real exports of developing countries by about 2 per cent, on average. G-3 exchange rate volatility also appears to have a negative influence on foreign direct investment to certain regions, and increases the probability of occurrence of exchange rate crises in developing countries. These results imply that greater stability in the international exchange rate system would help improve trade and foreign direct investment prospects for developing countries – and would help prevent currency crises.
Casimir force calculations near the insulator-conductor transition in gold thin films
We present theoretical calculations of the Casimir force for Au thin films
near the insulator-conductor transition that has been observed experimentally.
The dielectric function of the Au thin films is described by the Drude-Smith
model. The parameters needed to model the dielectric function such as the
relaxation time, plasma frequency and the backscattering constant depend on the
thickness of the film. The Casimir force decreases as the film thickness
decreases until it reaches a minimum after which the force increases again. The
minimum of the force coincides with the critical film thickness where a
percolation conductor-insulator occurs.Comment: 5 figures, 1 tabl
Van der Waals torque induced by external magnetic fields
We present a method for inducing and controlling van der Waals torques
between two parallel slabs using a constant magnetic field. The torque is
calculated using the Barash theory of dispersive torques. In III-IV
semiconductors such as , the effect of an external magnetic field is to
induce an optical anisotropy, in an otherwise isotropic material, that will in
turn induce a torque.
The calculations of the torque are done in the Voigt configuration, with the
magnetic field parallel to the surface of the slabs. As a case study we
consider a slab made of calcite and a second slab made of . In the
absence of magnetic field there is no torque. As the magnetic field increases,
the optical anisotropy of increases and the torque becomes different
from zero, increasing with the magnetic field. The resulting torque is of the
same order of magnitude as that calculated using permanent anisotropic
materials when the magnetic fields is close to 1 T.Comment: to appear in Journal of Applied Physic
Spatial dispersion in Casimir forces: A brief review
We present the basic principles of non-local optics in connection with the
calculation of the Casimir force between half-spaces and thin films.
At currently accessible distances , non-local corrections amount to about
half a percent, but they increase roughly as 1/L at smaller separations. Self
consistent models lead to corrections with the opposite sign as models with
abrupt surfaces.Comment: Proceedings of QFEXT05, Barcelona, Sept. 5-9, 200
Statistics of Velocity from Spectral Data: Modified Velocity Centroids
We address the problem of studying interstellar turbulence using spectral
line data. We find a criterion when the velocity centroids may provide
trustworthy velocity statistics. To enhance the scope of centroids
applications, we construct a measure that we term ``modified velocity
centroids'' (MVCs) and derive an analytical solution that relates the 2D
spectra of the modified centroids with the underlying 3D velocity spectrum. We
test our results using synthetic maps constructed with data obtained through
simulations of compressible magnetohydrodynamical (MHD) turbulence. We show
that the modified velocity centroids (MVCs) are complementary to the the
Velocity Channel Analysis (VCA) technique. Employed together, they make
determining of the velocity spectral index more reliable and for wider variety
of astrophysical situations.Comment: 4 pages, 1 figure, Accepted for publication in ApJ Letters. minor
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Jeans instability of a galactic disk embedded in a live dark halo
We investigate the Jeans instability of a galactic disk embedded in a
dynamically responsive dark halo. It is shown that the disk-halo system becomes
nominally Jeans unstable. On small scales the instability is suppressed, if the
Toomre stability index Q_T is higher than a certain threshold, but on large
scales the Jeans instability sets invariably in. However, using a simple
self-consistent disk-halo model it is demonstrated that this occurs on scales
which are much larger than the system so that this is indeed only a nominal
effect. From a practical point of view the Jeans instability of galactic disks
is not affected by a live dark halo.Comment: 3 pages, 1 figure, accepted by Astron. Astrophy
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