1,744 research outputs found
Symplecton for U_h(sl(2)) and representations of SL_h(2)
Polynomials of boson creation and annihilation operators which form
irreducible tensor operators for Jordanian quantum algebra U_h(sl(2)), called
h-symplecton, are introduced and their properties are investigated. It is shown
that many properties of symplecton for Lie algebra sl(2) are extended to
h-symplecton. The h-symplecton is also a basis of irreducible representation of
SL_h(2) dual to U_h(sl(2)). As an application of the procedure used to
construct h-symplecton, we construct the representation bases of SL_h(2) on the
quantum h-plane.Comment: 20 pages, LaTeX2e, no figures, to be published in J.Math.Phy
Strong magnetic field enhancement of spin triplet pairing arising from coexisting spin and charge fluctuations
We study the effect of the magnetic field (Zeeman splitting) on the triplet
pairing. We show generally that the enhancement of spin triplet pairing
mediated by coexisting spin and charge fluctuations can be much
larger than in the case of triplet pairing mediated by ferromagnetic spin
fluctuations. We propose that this may be related to the recent experiment for
(TMTSF)ClO, in which a possibility of singlet to triplet pairing
transition has been suggested.Comment: 5 page
International Financial Regulatory Standards and Human Rights: Connecting the Dots
This paper’s hypothesis is that the international standard setting bodies (SSBs) could improve the quality of their international standards by incorporating a human rights analysis. It focuses on five SSBs and seven of their international standards and its findings include the following: First, the standards all implicate the right of non-discrimination, and the rights to information, privacy and an effective remedy. Second, they each raises economic, social and cultural rights issues, including the obligation to allocate ‘maximum available resources’ to the progressive realization of economic, social and cultural rights; the human rights responsibilities of private actors exercising delegated regulatory authority, and the need for financial decision-makers to account for all the impacts and risks of their decisions and actions. Third, the SSBs’ failure to utilize such international standards as the UNGPs, the PRI, and the Equator Principles means that they have not comprehensively addressed the risk factors facing the financial sector. Fourth, the benefits that the SSBs gain from utilizing a human rights analysis outweigh their costs. Fifth, there are manageable risks to human rights if the financial sector adopts a human rights approach
Basic Hypergeometric Functions and Covariant Spaces for Even Dimensional Representations of U_q[osp(1/2)]
Representations of the quantum superalgebra U_q[osp(1/2)] and their relations
to the basic hypergeometric functions are investigated. We first establish
Clebsch-Gordan decomposition for the superalgebra U_q[osp(1/2)] in which the
representations having no classical counterparts are incorporated. Formulae for
these Clebsch-Gordan coefficients are derived, and it is observed that they may
be expressed in terms of the -Hahn polynomials. We next investigate
representations of the quantum supergroup OSp_q(1/2) which are not well-defined
in the classical limit. Employing the universal T-matrix, the representation
matrices are obtained explicitly, and found to be related to the little
Q-Jacobi polynomials. Characteristically, the relation Q = -q is satisfied in
all cases. Using the Clebsch-Gordan coefficients derived here, we construct new
noncommutative spaces that are covariant under the coaction of the even
dimensional representations of the quantum supergroup OSp_q(1/2).Comment: 16 pages, no figure
A lattice dynamical treatment for the total potential energy of single-walled carbon nanotubes and its applications: relaxed equilibrium structure, elastic properties, and vibrational modes of ultra-narrow tubes
In this paper, we proposed a lattice dynamic treatment for the total
potential energy for single-walled carbon nanotubes (SWCNT's) which is, apart
from a parameter for the non-linear effects, extracted from the vibrational
energy of the planar graphene sheet. Based upon the proposal, we investigated
systematically the relaxed lattice configuration for narrow SWCNT's, the strain
energy, the Young's modulus and Poisson ratio, and the lattice vibrational
properties respected to the relaxed equilibrium tubule structure. Our
calculated results for various physical quantities are nicely in consistency
with existing experimental measurements. Particularly, we verified that the
relaxation effect brings the bond length longer and the frequencies of various
optical vibrational modes softer; Our calculation provides the evidence that
the Young's modulus of armchair tube exceeds that of the planar graphene sheet,
and the large diameter limits of the Young's modulus and Poisson ratio are in
agreement with the experimental values of the graphite; The calculated radial
breathing modes for the ultra narrow tubes with diameter range between 0.2 -
0.5 nm coincide the experimental results and the existing {\it ab initio}
calculations with satisfaction; For narrow tubes of diameter 2 nm, the
calculated frequencies of optical modes in tubule tangential plane as well as
those of radial breathing modes are also in good agreement with the
experimental measurement. In addition, our calculation shows that various
physical quantities of relaxed SWCNT's can actually be expanded in terms of the
chiral angle defined for the correspondent ideal SWCNT's.Comment: 9 pages, 7 figure
Quantization of Lie-Poisson structures by peripheric chains
The quantization properties of composite peripheric twists are studied.
Peripheric chains of extended twists are constructed for U(sl(N)) in order to
obtain composite twists with sufficiently large carrier subalgebras. It is
proved that the peripheric chains can be enlarged with additional Reshetikhin
and Jordanian factors. This provides the possibility to construct new solutions
to Drinfeld equations and, thus, to quantize new sets of Lie-Poisson
structures. When the Jordanian additional factors are used the carrier algebras
of the enlarged peripheric chains are transformed into algebras of motion of
the form G_{JB}^{P}={G}_{H}\vdash {G}_{P}. The factor algebra G_{H} is a direct
sum of Borel and contracted Borel subalgebras of lower dimensions. The
corresponding omega--form is a coboundary. The enlarged peripheric chains
F_{JB}^{P} represent the twists that contain operators external with respect to
the Lie-Poisson structure. The properties of new twists are illustrated by
quantizing r-matrices for the algebras U(sl(3)), U(sl(4)) and U(sl(7)).Comment: 24 pages, LaTe
Effect of heuristics on serendipity in path-based storytelling with linked data
Path-based storytelling with Linked Data on the Web provides users the ability to discover concepts in an entertaining and educational way. Given a query context, many state-of-the-art pathfinding approaches aim at telling a story that coincides with the user's expectations by investigating paths over Linked Data on the Web. By taking into account serendipity in storytelling, we aim at improving and tailoring existing approaches towards better fitting user expectations so that users are able to discover interesting knowledge without feeling unsure or even lost in the story facts. To this end, we propose to optimize the link estimation between - and the selection of facts in a story by increasing the consistency and relevancy of links between facts through additional domain delineation and refinement steps. In order to address multiple aspects of serendipity, we propose and investigate combinations of weights and heuristics in paths forming the essential building blocks for each story. Our experimental findings with stories based on DBpedia indicate the improvements when applying the optimized algorithm
Laughlin states on the Poincare half-plane and its quantum group symmetry
We find the Laughlin states of the electrons on the Poincare half-plane in
different representations. In each case we show that there exist a quantum
group symmetry such that the Laughlin states are a representation of
it. We calculate the corresponding filling factor by using the plasma analogy
of the FQHE.Comment: 9 pages,Late
Electron-phonon effects and transport in carbon nanotubes
We calculate the electron-phonon scattering and binding in semiconducting
carbon nanotubes, within a tight binding model. The mobility is derived using a
multi-band Boltzmann treatment. At high fields, the dominant scattering is
inter-band scattering by LO phonons corresponding to the corners K of the
graphene Brillouin zone. The drift velocity saturates at approximately half the
graphene Fermi velocity. The calculated mobility as a function of temperature,
electric field, and nanotube chirality are well reproduced by a simple
interpolation formula. Polaronic binding give a band-gap renormalization of ~70
meV, an order of magnitude larger than expected. Coherence lengths can be quite
long but are strongly energy dependent.Comment: 5 pages and 4 figure
Improving the Representation and Conversion of Mathematical Formulae by Considering their Textual Context
Mathematical formulae represent complex semantic information in a concise
form. Especially in Science, Technology, Engineering, and Mathematics,
mathematical formulae are crucial to communicate information, e.g., in
scientific papers, and to perform computations using computer algebra systems.
Enabling computers to access the information encoded in mathematical formulae
requires machine-readable formats that can represent both the presentation and
content, i.e., the semantics, of formulae. Exchanging such information between
systems additionally requires conversion methods for mathematical
representation formats. We analyze how the semantic enrichment of formulae
improves the format conversion process and show that considering the textual
context of formulae reduces the error rate of such conversions. Our main
contributions are: (1) providing an openly available benchmark dataset for the
mathematical format conversion task consisting of a newly created test
collection, an extensive, manually curated gold standard and task-specific
evaluation metrics; (2) performing a quantitative evaluation of
state-of-the-art tools for mathematical format conversions; (3) presenting a
new approach that considers the textual context of formulae to reduce the error
rate for mathematical format conversions. Our benchmark dataset facilitates
future research on mathematical format conversions as well as research on many
problems in mathematical information retrieval. Because we annotated and linked
all components of formulae, e.g., identifiers, operators and other entities, to
Wikidata entries, the gold standard can, for instance, be used to train methods
for formula concept discovery and recognition. Such methods can then be applied
to improve mathematical information retrieval systems, e.g., for semantic
formula search, recommendation of mathematical content, or detection of
mathematical plagiarism.Comment: 10 pages, 4 figure
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