196 research outputs found

    Deforming Maps for Lie Group Covariant Creation and Annihilation Operators

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    Any deformation of a Weyl or Clifford algebra A can be realized through a `deforming map', i.e. a formal change of generators in A. This is true in particular if A is covariant under a Lie algebra g and its deformation is induced by some triangular deformation UhgU_h g of the Hopf algebra UgUg. We propose a systematic method to construct all the corresponding deforming maps, together with the corresponding realizations of the action of UhgU_h g. The method is then generalized and explicitly applied to the case that UhgU_h g is the quantum group Uhsl(2)U_h sl(2). A preliminary study of the status of deforming maps at the representation level shows in particular that `deformed' Fock representations induced by a compact UhgU_h g can be interpreted as standard `undeformed' Fock representations describing particles with ordinary Bose or Fermi statistics.Comment: Latex file, 26 pages, no figures. Extended changes. Final Version to appear in J. Math. Phy

    Modeling Expertise in Assistive Navigation Interfaces for Blind People

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    Evaluating the impact of expertise and route knowledge on task performance can guide the design of intelligent and adaptive navigation interfaces. Expertise has been relatively unexplored in the context of assistive indoor navigation interfaces for blind people. To quantify the complex relationship between the user's walking patterns, route learning, and adaptation to the interface, we conducted a study with 8 blind participants. The participants repeated a set of navigation tasks while using a smartphone-based turn-by-turn navigation guidance app. The results demonstrate the gradual evolution of user skill and knowledge throughout the route repetitions, significantly impacting the task completion time. In addition to the exploratory analysis, we take a step towards tailoring the navigation interface to the user's needs by proposing a personalized recurrent neural net work-based behavior model for expertise level classification

    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

    h-deformation of Gr(2)

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    The hh-deformation of functions on the Grassmann matrix group Gr(2)Gr(2) is presented via a contraction of Grq(2)Gr_q(2). As an interesting point, we have seen that, in the case of the hh-deformation, both R-matrices of GLh(2)GL_h(2) and Grh(2)Gr_h(2) are the same

    Non-standard quantum so(3,2) and its contractions

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    A full (triangular) quantum deformation of so(3,2) is presented by considering this algebra as the conformal algebra of the 2+1 dimensional Minkowskian spacetime. Non-relativistic contractions are analysed and used to obtain quantum Hopf structures for the conformal algebras of the 2+1 Galilean and Carroll spacetimes. Relations between the latter and the null-plane quantum Poincar\'e algebra are studied.Comment: 9 pages, LaTe

    Integrable deformations of oscillator chains from quantum algebras

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    A family of completely integrable nonlinear deformations of systems of N harmonic oscillators are constructed from the non-standard quantum deformation of the sl(2,R) algebra. Explicit expressions for all the associated integrals of motion are given, and the long-range nature of the interactions introduced by the deformation is shown to be linked to the underlying coalgebra structure. Separability and superintegrability properties of such systems are analysed, and their connection with classical angular momentum chains is used to construct a non-standard integrable deformation of the XXX hyperbolic Gaudin system.Comment: 15 pages, LaTe

    Customized television: Standards compliant advanced digital television

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    This correspondence describes a European Union supported collaborative project called CustomTV based on the premise that future TV sets will provide all sorts of multimedia information and interactivity, as well as manage all such services according to each user’s or group of user’s preferences/profiles. We have demonstrated the potential of recent standards (MPEG-4 and MPEG-7) to implement such a scenario by building the following services: an advanced EPG, Weather Forecasting, and Stock Exchange/Flight Information

    Jordanian Twist Quantization of D=4 Lorentz and Poincare Algebras and D=3 Contraction Limit

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    We describe in detail two-parameter nonstandard quantum deformation of D=4 Lorentz algebra o(3,1)\mathfrak{o}(3,1), linked with Jordanian deformation of sl(2;C)\mathfrak{sl} (2;\mathbb{C}). Using twist quantization technique we obtain the explicit formulae for the deformed coproducts and antipodes. Further extending the considered deformation to the D=4 Poincar\'{e} algebra we obtain a new Hopf-algebraic deformation of four-dimensional relativistic symmetries with dimensionless deformation parameter. Finally, we interpret o(3,1)\mathfrak{o}(3,1) as the D=3 de-Sitter algebra and calculate the contraction limit RR\to\infty (RR -- de-Sitter radius) providing explicit Hopf algebra structure for the quantum deformation of the D=3 Poincar\'{e} algebra (with masslike deformation parameters), which is the two-parameter light-cone κ\kappa-deformation of the D=3 Poincar\'{e} symmetry.Comment: 13 pages, no figure

    Universal RR--matrices for non-standard (1+1) quantum groups

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    A universal quasitriangular RR--matrix for the non-standard quantum (1+1) Poincar\'e algebra Uziso(1,1)U_ziso(1,1) is deduced by imposing analyticity in the deformation parameter zz. A family gμg_\mu of ``quantum graded contractions" of the algebra Uziso(1,1)Uziso(1,1)U_ziso(1,1)\oplus U_{-z}iso(1,1) is obtained; this set of quantum algebras contains as Hopf subalgebras with two primitive translations quantum analogues of the two dimensional Euclidean, Poincar\'e and Galilei algebras enlarged with dilations. Universal RR--matrices for these quantum Weyl algebras and their associated quantum groups are constructed.Comment: 12 pages, LaTeX

    Classification of the quantum deformation of the superalgebra GL(11)GL(1|1)

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    We present a classification of the possible quantum deformations of the supergroup GL(11)GL(1|1) and its Lie superalgebra gl(11)gl(1|1). In each case, the (super)commutation relations and the Hopf structures are explicitly computed. For each RR matrix, one finds two inequivalent coproducts whether one chooses an unbraided or a braided framework while the corresponding structures are isomorphic as algebras. In the braided case, one recovers the classical algebra gl(11)gl(1|1) for suitable limits of the deformation parameters but this is no longer true in the unbraided case.Comment: 23p LaTeX2e Document - packages amsfonts,subeqn - misprints and errors corrected, one section adde
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