7,397 research outputs found
On interpretations and constructions of classical dynamical r-matrices
In this note we complement recent results on the exchange -matrices
appearing in the chiral WZNW model by providing a direct, purely
finite-dimensional description of the relationship between the monodromy
dependent 2-form that enters the chiral WZNW symplectic form and the exchange
-matrix that governs the corresponding Poisson brackets. We also develop the
special case in which the exchange -matrix becomes the `canonical' solution
of the classical dynamical Yang-Baxter equation on an arbitrary self-dual Lie
algebra.Comment: 8 pages, LaTeX, based on a talk given by L.F. at the QTS2 symposium,
18-21 July 2001, Krakow, Poland. References are updated, and a typo is
removed in v2; a misprint in equation (A.13) is corrected in v
Has emerging Asia decoupled? An analysis of production and trade linkages using the Asian international input-output table
Due to the emergence of global production networks, trade statistics have became less accurate in describing the dependence of emerging Asia on external demand. This paper analyses, using an update of the Asian International Input-Output (AIO) table, the interdependence of emerging Asian countries, the United States, the EU15, and Japan via trade and production linkages. According to the results, we do not find evidence of the decoupling of emerging Asia from the rest of the world. On the contrary, we find evidence on increasing trade integration, both globally and regionally. Nonetheless, our analysis indicates that emerging Asia’s dependence on exports is only about one-third of its GDP, i.e. well below the 50% exposure suggested by trade data. This finding can be explained by the high import content of exports in these economies, which is a result of the increasing segmentation of production across the region. JEL Classification: F14, C67, E23Asian International Input-Output table, decoupling, Emerging Asia, real linkages, resilience
Chiral Disorder and Diffusion of Light Quarks in the QCD Vacuum
We give a pedagogical introduction to the concept that light quarks diffuse
in the QCD vacuum following the spontaneous breaking of chiral symmetry. By
analogy with disordered electrons in metals, we show that the diffusion
constant for light quarks in QCD is D=2F_{\pi}^2/|\la\bar{q}q\to| which is
about 0.22 fm. We comment on the correspondence between the diffusive phase and
the chiral phase as described by chiral perturbation theory, as well as the
cross-over to the ergodic phase as described by random matrix theory. The
cross-over is identified with the Thouless energy which is
the inverse diffusion time in an Euclidean four-volume .Comment: 9 pages in APPB sty (included). Invited talk by MAN at the Workshop
on the Structure of Mesons, Baryons and Nuclei, Cracow, May 26-30, 199
U(1) Problem at Finite Temperature
We model the effects of a large number of zero and near-zero modes in the QCD
partition function by using sparse chiral matrix models with an emphasis on the
quenched topological susceptibility in the choice of the measure. At finite
temperature, the zero modes are not affected by temperature but are allowed to
pair into topologically neutral near-zero modes which are gapped at high
temperature. In equilibrium, chiral and U(1) symmetry are simultaneously
restored for total pairing, evading mean-field arguments. We analyze a number
of susceptibilities versus the light quark masses. At the transition point the
topological susceptibility vanishes, and the dependence on the vacuum angle
drops out. Our results are briefly contrasted with recent lattice
simulations.Comment: 15 pages with 1 epf figure included; Proc of the Light-Cone Workshop
"New Directions in QCD", June 1999, Kyungju, Kore
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