389 research outputs found
Poisson-Lie T-Duality and Bianchi Type Algebras
All Bianchi bialgebras have been obtained. By introducing a non-degenerate
adjoint invariant inner product over these bialgebras the associated Drinfeld
doubles have been constructed, then by calculating the coupling matrices for
these bialgebras several sigma-models with Poisson-Lie symmetry have been
obtained. Two simple examples as prototypes of Poisson-Lie dual models have
been given.Comment: 16 pages, Latex; Some comments to the concluding section added,
references adde
Symplectic structures associated to Lie-Poisson groups
The Lie-Poisson analogues of the cotangent bundle and coadjoint orbits of a
Lie group are considered. For the natural Poisson brackets the symplectic
leaves in these manifolds are classified and the corresponding symplectic forms
are described. Thus the construction of the Kirillov symplectic form is
generalized for Lie-Poisson groups.Comment: 30 page
Prospects for coordination of the international legal regime of celestial bodies natural resources
The article deals with the analysis of different possible ways of creating international legal regime of celestial bodies natural resources. The effort of different international platforms to coordinate a legal regime of celestial bodies natural resources, including the Hague International Space Resources Governance Working Group, is analyzed. Several possible ways of establishing the corresponding international regime are discussed. Статья посвящена анализу перспектив согласования международно-правового режима природных ресурсов небесных тел. В статье рассмотрена деятельность различных международных площадок, включая Гаагскую рабочую группу по управлению космическими ресурсами, по согласованию соответствующего правового режима. Рассмотрены различные возможные варианты установления такого режима в рамках международного права
Small-angle fragmentation of carbon ions at 0.6 GeV/n: a comparison with models of ion-ion interactions
Momentum distributions of hydrogen and helium isotopes from 12C fragmentation at 3.5° were measured at 0.6 GeV/nucleon in the FRAGM experiment at ITEP TWA heavy ion accelerator. The fragments were selected by correlated time of flight and dE/dx measurements with a magnetic spectrometer with scintillation counters. The main attention was drawn to the high momentum region where the fragment velocity exceeds the velocity of the projectile nucleus. The momentum spectra of fragments span the region of the fragmentation peak as well as the cumulative region. The differential cross sections cover six orders of magnitude. The distributions measured are compared to the predictions of three ion-ion interaction models: BC, QMD and LAQGSM03.03. The kinetic energy spectra of fragments in the projectile rest frame have an exponential shape with two temperatures, being defined by their slope parameters
Poisson-Lie generalization of the Kazhdan-Kostant-Sternberg reduction
The trigonometric Ruijsenaars-Schneider model is derived by symplectic
reduction of Poisson-Lie symmetric free motion on the group U(n). The commuting
flows of the model are effortlessly obtained by reducing canonical free flows
on the Heisenberg double of U(n). The free flows are associated with a very
simple Lax matrix, which is shown to yield the Ruijsenaars-Schneider Lax matrix
upon reduction.Comment: 13 pages, LaTeX, minor modifications and references added in v
More on quantum groups from the the quantization point of view
Star products on the classical double group of a simple Lie group and on
corresponding symplectic grupoids are given so that the quantum double and the
"quantized tangent bundle" are obtained in the deformation description.
"Complex" quantum groups and bicovariant quantum Lie algebras are discused from
this point of view. Further we discuss the quantization of the Poisson
structure on symmetric algebra leading to the quantized enveloping
algebra as an example of biquantization in the sense of Turaev.
Description of in terms of the generators of the bicovariant
differential calculus on is very convenient for this purpose. Finally
we interpret in the deformation framework some well known properties of compact
quantum groups as simple consequences of corresponding properties of classical
compact Lie groups. An analogue of the classical Kirillov's universal character
formula is given for the unitary irreducible representation in the compact
case.Comment: 18 page
Entropy and Quantum Kolmogorov Complexity: A Quantum Brudno's Theorem
In classical information theory, entropy rate and Kolmogorov complexity per
symbol are related by a theorem of Brudno. In this paper, we prove a quantum
version of this theorem, connecting the von Neumann entropy rate and two
notions of quantum Kolmogorov complexity, both based on the shortest qubit
descriptions of qubit strings that, run by a universal quantum Turing machine,
reproduce them as outputs.Comment: 26 pages, no figures. Reference to publication added: published in
the Communications in Mathematical Physics
(http://www.springerlink.com/content/1432-0916/
Water waves generated by a moving bottom
Tsunamis are often generated by a moving sea bottom. This paper deals with
the case where the tsunami source is an earthquake. The linearized water-wave
equations are solved analytically for various sea bottom motions. Numerical
results based on the analytical solutions are shown for the free-surface
profiles, the horizontal and vertical velocities as well as the bottom
pressure.Comment: 41 pages, 13 figures. Accepted for publication in a book: "Tsunami
and Nonlinear Waves", Kundu, Anjan (Editor), Springer 2007, Approx. 325 p.,
170 illus., Hardcover, ISBN: 978-3-540-71255-8, available: May 200
Views of the Chiral Magnetic Effect
My personal views of the Chiral Magnetic Effect are presented, which starts
with a story about how we came up with the electric-current formula and
continues to unsettled subtleties in the formula. There are desirable features
in the formula of the Chiral Magnetic Effect but some considerations would lead
us to even more questions than elucidations. The interpretation of the produced
current is indeed very non-trivial and it involves a lot of confusions that
have not been resolved.Comment: 19 pages, no figure; typos corrected, references significantly
updated, to appear in Lect. Notes Phys. "Strongly interacting matter in
magnetic fields" (Springer), edited by D. Kharzeev, K. Landsteiner, A.
Schmitt, H.-U. Ye
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