14,850 research outputs found
Argentina's default and the lack of dire consequences
We analyze the 2001 Argentine default on its foreign debt and its consequences in terms of the existing literature on sovereign debt default. It is our purpose to evaluate this experience and to see to what extent the Argentine case requires a re-thinking on the nature and consequences of defaults. We show that the Argentine case contradicts many of their standard predictions, in particular its posterior lack of access to international credit, restriction to international trade and negative economic growth. Moreover, it corroborates the historical fact that many defaulters “get away with it.
Localization of gauge fields in a tachyonic de Sitter thick braneworld
In this work we show that universal gauge vector fields can be localized on
the recently proposed 5D thick tachyonic braneworld which involves a de Sitter
cosmological background induced on the 3-brane. Namely, by performing a
suitable decomposition of the vector field, the resulting 4D effective action
corresponds to a massive gauge field, while the profile along the extra
dimension obeys a Schroedinger-like equation with a Poeschl-Teller potential.
It turns out that the massless zero mode of the gauge field is bound to the
expanding 3-brane and allows us to recover the standard 4D electromagnetic
phenomena of our world. Moreover, this zero mode is separated from the
continuum of Kaluza-Klein (KK) modes by a mass gap determined by the scale of
the expansion parameter. We also were able to analytically solve the
corresponding Schroedinger-like equation for arbitrary mass, showing that KK
massive modes asymptotically behave like plane waves as expected.Comment: 7 pages in latex, no figure
GTD analysis of airborne antennas radiating in the presence of lossy dielectric layers
The patterns of monopole or aperture antennas mounted on a perfectly conducting convex surface radiating in the presence of a dielectric or metal plate are computed. The geometrical theory of diffraction is used to analyze the radiating system and extended here to include diffraction by flat dielectric slabs. Modified edge diffraction coefficients valid for wedges whose walls are lossy or lossless thin dielectric or perfectly conducting plates are developed. The width of the dielectric plates cannot exceed a quarter of a wavelength in free space, and the interior angle of the wedge is assumed to be close to 0 deg or 180 deg. Systematic methods for computing the individual components of the total high frequency field are discussed. The accuracy of the solutions is demonstrated by comparisons with measured results, where a 2 lambda by 4 lambda prolate spheroid is used as the convex surface. A jump or kink appears in the calculated pattern when higher order terms that are important are not included in the final solution. The most immediate application of the results presented here is in the modelling of structures such as aircraft which are composed of nonmetallic parts that play a significant role in the pattern
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