7,028 research outputs found
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A Structural Analysis of Chile's Long-Term Growth: History, Prospects and Policy Implications
symmetry and quasi-normal modes in the BTZ black hole
With the help of two new intrinsic tensor fields associated with the
quadratic Casimir of Killing fields, we uncover the
symmetry satisfied by the solutions to the equations of motion for various
fields in the BTZ black hole in a uniform way by performing tensor and spinor
analysis without resorting to any specific coordinate system. Then with the
standard algebraic method developed recently, we determine the quasi-normal
modes for various fields in the BTZ black hole. As a result, the quasi-normal
modes are given by the infinite tower of descendants of the chiral highest
weight mode, which is in good agreement with the previous analytic result
obtained by exactly solving equations of motion instead.Comment: JHEP style, 1+13 pages, version to appear in JHE
A Riemann-Hilbert Problem for an Energy Dependent Schr\"odinger Operator
\We consider an inverse scattering problem for Schr\"odinger operators with
energy dependent potentials. The inverse problem is formulated as a
Riemann-Hilbert problem on a Riemann surface. A vanishing lemma is proved for
two distinct symmetry classes. As an application we prove global existence
theorems for the two distinct systems of partial differential equations
for suitably restricted,
complementary classes of initial data
(2,2)-Formalism of General Relativity: An Exact Solution
I discuss the (2,2)-formalism of general relativity based on the
(2,2)-fibration of a generic 4-dimensional spacetime of the Lorentzian
signature. In this formalism general relativity is describable as a Yang-Mills
gauge theory defined on the (1+1)-dimensional base manifold, whose local gauge
symmetry is the group of the diffeomorphisms of the 2-dimensional fibre
manifold. After presenting the Einstein's field equations in this formalism, I
solve them for spherically symmetric case to obtain the Schwarzschild solution.
Then I discuss possible applications of this formalism.Comment: 2 figures included, IOP style file neede
On the Weyl transverse frames in type I spacetimes
We apply a covariant and generic procedure to obtain explicit expressions of
the transverse frames that a type I spacetime admits in terms of an arbitrary
initial frame. We also present a simple and general algorithm to obtain the
Weyl scalars , and associated with these
transverse frames. In both cases it is only necessary to choose a particular
root of a cubic expression.Comment: 12 pages, submitted to Gen. Rel. Grav. (6-3-2004
A note on the uniqueness of global static decompositions
We discuss when static Killing vector fields are standard, that is, leading
to a global orthogonal splitting of the spacetime. We prove that such an
orthogonal splitting is unique whenever the natural space is compact. This is
carried out by proving that many notable spacelike submanifolds must be
contained in an orthogonal slice. Possible obstructions to the global splitting
are also considered.Comment: 6 pages, no figure
Cosmological Perturbations of Quantum-Mechanical Origin and Anisotropy of the Microwave Background
Cosmological perturbations generated quantum-mechanically (as a particular
case, during inflation) possess statistical properties of squeezed quantum
states. The power spectra of the perturbations are modulated and the angular
distribution of the produced temperature fluctuations of the CMBR is quite
specific. An exact formula is derived for the angular correlation function of
the temperature fluctuations caused by squeezed gravitational waves. The
predicted angular pattern can, in principle, be revealed by the COBE-type
observations.Comment: 9 pages, WUGRAV-92-17 Accepted for Publication in Phys. Rev. Letters
(1993
Cosmic Microwave Background Dipole induced by double inflation
The observed CMBR dipole is generally interpreted as the consequence of the
peculiar motion of the Sun with respect to the reference frame of the CMBR.
This article proposes an alternative interpretation in which the observed
dipole is the result of isocurvature perturbations on scales larger than the
present Hubble radius. These perturbations are produced in the simplest model
of double inflation, depending on three parameters. The observed dipole and
quadrupole can be explained in this model, while severely constraining its
parameters.Comment: Latex, 9 pages, no figure, to appear in Phys. Rev.
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Contractionary Devaluation, and Dynamic Adjustment of Exports and Wages
Recent macroeconomic models of developing countries have emphasized the possibility of contactionary devaluations, stressing that domestic aggregate demand is likely to be reduced by the devaluations while aggregate supply may respond only slowly to the change in relative prices brought about by the devaluation. These results have been obtained in static models. In this paper we add wage and export-sector dynamics to the models of contractionary devaluation, and show that the effects which produce contractionary devaluations in the short term can produce limit cycles in the long run. The economy never returns to long-run equilibrium following a devaluation, but rather moves with fixed periodicity through successive phases of boom and bust
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