137 research outputs found

    Representations of SU(1,1) in Non-commutative Space Generated by the Heisenberg Algebra

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    SU(1,1) is considered as the automorphism group of the Heisenberg algebra H. The basis in the Hilbert space K of functions on H on which the irreducible representations of the group are realized is explicitly constructed. The addition theorems are derived.Comment: Latex, 8 page

    Quantum Group Covariance and the Braided Structure of Deformed Oscillators

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    The connection between braided Hopf algebra structure and the quantum group covariance of deformed oscillators is constructed explicitly. In this context we provide deformations of the Hopf algebra of functions on SU(1,1). Quantum subgroups and their representations are also discussed.Comment: 12 pages, to be published in JM

    Two Dimensional Fractional Supersymmetry from the Quantum Poincare Group at Roots of Unity

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    A group theoretical understanding of the two dimensional fractional supersymmetry is given in terms of the quantum Poincare group at roots of unity. The fractional supersymmetry algebra and the quantum group dual to it are presented and the pseudo-unitary, irreducible representations of them are obtained. The matrix elements of these representations are explicitly constructed.Comment: 10 pages. Some misprints are corrected. To appear in J. Phys.

    More on New Massive Gravity: Exact Solutions

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    We give a novel description of the recently proposed theory of new massive gravity (NMG) in three dimensions. We show that in terms of a Dirac type differential operator acting on the traceless Ricci tensor, the field equations of the theory reduce to the massive Klein-Gordon type equation with a curvature-squared source term and to a constraint equation. Under a certain relation between the source tensor and the traceless Ricci tensor, fulfilled for constant scalar curvature, the field equations of topologically massive gravity (TMG) can be thought of as the "square-root" of the massive Klein-Gordon type equation. Using this fact, we establish a simple framework for mapping all known algebraic types D and N solutions of TMG into NMG. We also present new exact solutions of algebraic types D and N which are only inherent in NMG.Comment: 4 pages, twocolumn REVTeX; Minor cosmetic changes made and new metric adde

    Explaining the subpulse drift velocity of pulsar magnetosphere within the space-charge limited flow model

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    We try to explain the subpulse drift phenomena adopting the space-charge limited flow (SCLF) model and comparing the plasma drift velocity in the inner region of pulsar magnetospheres with the observed velocity of drifting subpulses. We apply the approach described in a recent paper of van Leeuwen & Timokhin (2012), where it was shown that the standard estimation of the subpulse drift velocity through the total value of the scalar potential drop in the inner gap gives inaccurate results, while the exact expression relating the drift velocity to the gradient of the scalar potential should be used instead. After considering a selected sample of sources taken from the catalog of Weltevrede, Edwards & Stappers (2006) with coherently drifting subpulses and reasonably known observing geometry, we show that their subpulse drift velocities would correspond to the drift of the plasma located very close or above the pair formation front. Moreover, a detailed analysis of PSR B0826-34 and PSR B0818-41 reveals that the variation of the subpulse separation with the pulse longitude can be successfully explained by the dependence of the plasma drift velocity on the angular coordinates.Comment: 14 pages, 6 figures, 2 table

    General Relativistic Magnetospheres of Slowly Rotating and Oscillating Magnetized Neutron Stars

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    We study the magnetosphere of a slowly rotating magnetized neutron star subject to toroidal oscillations in the relativistic regime. Under the assumption of a zero inclination angle between the magnetic moment and the angular momentum of the star, we analyze the Goldreich-Julian charge density and derive a second-order differential equation for the electrostatic potential. The analytical solution of this equation in the polar cap region of the magnetosphere shows the modification induced by stellar toroidal oscillations on the accelerating electric field and on the charge density. We also find that, after decomposing the oscillation velocity in terms of spherical harmonics, the first few modes with m=0,1m=0,1 are responsible for energy losses that are almost linearly dependent on the amplitude of the oscillation and that, for the mode (l,m)=(2,1)(l,m)=(2,1), can be a factor ∼8\sim8 larger than the rotational energy losses, even for a velocity oscillation amplitude at the star surface as small as η=0.05 Ω R\eta=0.05 \ \Omega \ R. The results obtained in this paper clarify the extent to which stellar oscillations are reflected in the time variation of the physical properties at the surface of the rotating neutron star, mainly by showing the existence of a relation between PP˙P\dot{P} and the oscillation amplitude. Finally, we propose a qualitative model for the explanation of the phenomenology of intermittent pulsars in terms of stellar oscillations that are periodically excited by star glitches.Comment: 13 pages, 4 figures, submitted to MNRA

    Braided Oscillators

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    The braided Hopf algebra structure of the generalized oscillator is investigated. Using the solutions two types of braided Fibonacci oscillators are introduced. This leads to two types of braided Biedenharn-Macfarlane oscillators.Comment: 12 pages, latex, some references added, published versio

    Fractional Super Lie Algebras and Groups

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    n^{th} root of a Lie algebra and its dual (that is fractional supergroup) based on the permutation group SnS_n invariant forms are formulated in the Hopf algebra formalism. Detailed discussion of S3S_3-graided sl(2)sl(2) algebras is done.Comment: 13 pages, detailed discussion of S3S_3-graided sl(2)sl(2) is adde
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