20,086 research outputs found
A System of n=3 Coupled Oscillators with Magnetic Terms: Symmetries and Integrals of Motion
The properties of a system of n = 3 coupled oscillators with linear terms in
the velocities (magnetic terms) depending in two parameters are studied. We
proved the existence of a bi-Hamiltonian structure arising from a
non-symplectic symmetry, as well the existence of master symmetries and
additional integrals of motion (weak superintegrability) for certain particular
values of the parameters.Comment: Published in SIGMA (Symmetry, Integrability and Geometry: Methods and
Applications) at http://www.emis.de/journals/SIGMA
The Tremblay-Turbiner-Winternitz system on spherical and hyperbolic spaces : Superintegrability, curvature-dependent formalism and complex factorization
The higher-order superintegrability of the Tremblay-Turbiner-Winternitz
system (related to the harmonic oscillator) is studied on the two-dimensional
spherical and hiperbolic spaces, S_\k^2 (\k>0), and H_{\k}^2 (\k<0).
The curvature is considered as a parameter and all the results are
formulated in explicit dependence of . The idea is that the additional
constant of motion can be factorized as the product of powers of two particular
rather simple complex functions (here denoted by and ). This
technique leads to a proof of the superintegrability of the
Tremblay-Turbiner-Winternitz system on S_\k^2 (\k>0) and H_{\k}^2
(\k<0), and to the explicit expression of the constants of motion.Comment: one figur
Photon Self-Energy in a Color Superconductor
In a color superconductor the diquark condensates break spontaneously both
the color and ordinary electromagnetism, leaving a remanining rotated U(1)
symmetry unbroken. The gauge interactions associated to this rotated symmetry
may be considered as the in-medium electromagnetism. We compute the in-medium
photon self-energy in the presence of diquark condensates at high baryonic
density and weak coupling. This is done to one-loop order for the cases of two
and three quark flavors. For vanishing temperature, a detailed discussion is
given of the low momentum behavior of the photon polarization tensor. A simple
physical picture for the propagation of light in color superconducting media is
obtained. The main new effect is due to the diquark condensates, which lead to
a strong dielectric constant of the medium. The magnetic permeability remains
unchanged, because the primary condensates have vanishing spin and angular
momentum. In the two flavor case, an additional contribution arises due to
gapless quarks and electrons, which is responsible for Debye screening effects.
We also discuss the low energy effective theory for the three flavor case in
the presence of electromagnetic interactions.Comment: 26 pages, 4 postscript figures, appendix added, to appear in PR
Deriving effective transport equations for non-Abelian plasmas
Within classical transport theory, an approach is presented to derive
systematically effective collision terms and noise sources for effective
kinetic equations of non-Abelian plasmas. This procedure amounts to the
`integrating-out' of fluctuations, and is applicable for in- and
out-of-equilibrium situations. When applied to a hot non-Abelian plasma close
to equilibrium we recover the collision integral and the noise source first
obtained by B\"odeker. It is also shown that our approach, and hence
B\"odeker's effective theory, is consistent with the fluctuation-dissipation
theorem.Comment: 7 pages, needs sprocl.sty, invited talk given by DFL at 5th workshop
on QCD (QCD2000), Villefranche-sur-Mer, France, 3-7 Jan 200
Review of Structural Adjustment in the Philippines
This article has been delivered during the Central Bank Diamond Jubilee celebration on November 21,1988. It reviews the issues of Philippine structural adjustments with a focus on the identification of elements in the past Philippine efforts that appear to be critical in the future adjustment endeavor. It also discusses the problems and the potentials of policy-based lending in support of future structural adjustment efforts in the Philippines.tax structure, agrarian reform, liberalization, structural adjustment, balance of payments, structural reforms, policy adjustment, industrialization
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