6,835 research outputs found

    Duals of coloured quantum universal enveloping algebras and coloured universal T\cal T-matrices

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    We extend the notion of dually conjugate Hopf (super)algebras to the coloured Hopf (super)algebras Hc{\cal H}^c that we recently introduced. We show that if the standard Hopf (super)algebras Hq{\cal H}_q that are the building blocks of Hc{\cal H}^c have Hopf duals Hq{\cal H}_q^*, then the latter may be used to construct coloured Hopf duals Hc{\cal H}^{c*}, endowed with coloured algebra and antipode maps, but with a standard coalgebraic structure. Next, we review the case where the Hq{\cal H}_q's are quantum universal enveloping algebras of Lie (super)algebras Uq(g)U_q(g), so that the corresponding Hq{\cal H}_q^*'s are quantum (super)groups GqG_q. We extend the Fronsdal and Galindo universal T{\cal T}-matrix formalism to the coloured pairs (Uc(g),Gc)(U^c(g), G^c) by defining coloured universal T{\cal T}-matrices. We then show that together with the coloured universal R\cal R-matrices previously introduced, the latter provide an algebraic formulation of the coloured RTT-relations, proposed by Basu-Mallick. This establishes a link between the coloured extensions of Drinfeld-Jimbo and Faddeev-Reshetikhin-Takhtajan pictures of quantum groups and quantum algebras. Finally, we illustrate the construction of coloured pairs by giving some explicit results for the two-parameter deformations of (U(gl(2)),Gl(2))\bigl(U(gl(2)), Gl(2)\bigr), and (U(gl(1/1)),Gl(1/1))\bigl(U(gl(1/1)), Gl(1/1)\bigr).Comment: LaTeX 2.09, 35 pages, no figur

    Generalized boson algebra and its entangled bipartite coherent states

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    Starting with a given generalized boson algebra U_(h(1)) known as the bosonized version of the quantum super-Hopf U_q[osp(1/2)] algebra, we employ the Hopf duality arguments to provide the dually conjugate function algebra Fun_(H(1)). Both the Hopf algebras being finitely generated, we produce a closed form expression of the universal T matrix that caps the duality and generalizes the familiar exponential map relating a Lie algebra with its corresponding group. Subsequently, using an inverse Mellin transform approach, the coherent states of single-node systems subject to the U_(h(1)) symmetry are found to be complete with a positive-definite integration measure. Nonclassical coalgebraic structure of the U_(h(1)) algebra is found to generate naturally entangled coherent states in bipartite composite systems.Comment: 15pages, no figur

    Focused browsing: Providing topical feedback for link selection in hypertext browsing

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    When making decisions about whether to navigate to a linked page, users of standard browsers of hypertextual documents returned by an information retrieval search engine are entirely reliant on the content of the anchortext associated with links and the surrounding text. This information is often insufficient for them to make reliable decisions about whether to open a linked page, and they can find themselves following many links to pages which are not helpful with subsequent return to the previous page. We describe a prototype focusing browsing application which provides feedback on the likely usefulness of each page linked from the current one, and a term cloud preview of the contents of each linked page. Results from an exploratory experiment suggest that users can find this useful in improving their search efficiency

    Multiple charge beam dynamics in Alternate Phase Focusing structure

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    Asymmetrical Alternate Phase (A-APF) focusing realized in a sequence of 36 Superconducting Quarter Wave Resonators has been shown to accelerate almost 81 % of input Uranium beam before foil stripper to an energy of 6.2 MeV/u from 1.3 MeV/u. Ten charge states from 34+ to 43+ could be simultaneously accelerated with the phase of resonators tuned for 34+. A-APF structure showed unique nature of large potential bucket for charge states higher than that of tuned one. Steering inherent to QWRs can be mitigated by selecting appropriate phase variation of the APF periods and optimization of solenoid field strengths placed in each of the periods. This mitigation facilitates multiple charge state acceleration schemeComment: 10 pages, 8 figure

    Particle Acceleration in Advection-Dominated Accretion Disks with Shocks: Green's Function Energy Distribution

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    The distribution function describing the acceleration of relativistic particles in an advection-dominated accretion disk is analyzed using a transport formalism that includes first-order Fermi acceleration, advection, spatial diffusion, and the escape of particles through the upper and lower surfaces of the disk. When a centrifugally-supported shock is present in the disk, the concentrated particle acceleration occurring in the vicinity of the shock channels a significant fraction of the binding energy of the accreting gas into a population of relativistic particles. These high-energy particles diffuse vertically through the disk and escape, carrying away both energy and entropy and allowing the remaining gas to accrete. The dynamical structure of the disk/shock system is computed self-consistently using a model previously developed by the authors that successfully accounts for the production of the observed relativistic outflows (jets) in M87 and \SgrA. This ensures that the rate at which energy is carried away from the disk by the escaping relativistic particles is equal to the drop in the radial energy flux at the shock location, as required for energy conservation. We investigate the influence of advection, diffusion, and acceleration on the particle distribution by computing the nonthermal Green's function, which displays a relatively flat power-law tail at high energies. We also obtain the energy distribution for the particles escaping from the disk, and we conclude by discussing the spectrum of the observable secondary radiation produced by the escaping particles.Comment: Published in Ap

    The Gervais-Neveu-Felder equation for the Jordanian quasi-Hopf U_{h;y}(sl(2)) algebra

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    Using a contraction procedure, we construct a twist operator that satisfies a shifted cocycle condition, and leads to the Jordanian quasi-Hopf U_{h;y}(sl(2)) algebra. The corresponding universal Rh(y){\cal R}_{h}(y) matrix obeys a Gervais-Neveu-Felder equation associated with the U_{h;y}(sl(2)) algebra. For a class of representations, the dynamical Yang-Baxter equation may be expressed as a compatibility condition for the algebra of the Lax operators.Comment: Latex, 9 pages, no figure
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