52 research outputs found

    Newton-Hooke type symmetry of anisotropic oscillators

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    The rotation-less Newton--Hooke - type symmetry found recently in the Hill problem and instrumental for explaining the center-of-mass decomposition is generalized to an arbitrary anisotropic oscillator in the plane. Conversely, the latter system is shown, by the orbit method, to be the most general one with such a symmetry. Full Newton-Hooke symmetry is recovered in the isotropic case. Star escape from a Galaxy is studied as application.Comment: Updated version with more figures added. 34 pages, 7 figures. Dedicated to the memory of J.-M. Souriau, deceased on March 15 2012, at the age of 9

    Maxwell - Chern - Simons topologically massive gauge fields in the first-order formalism

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    We find the canonical and Belinfante energy-momentum tensors and their nonzero traces. We note that the dilatation symmetry is broken and the divergence of the dilatation current is proportional to the topological mass of the gauge field. It was demonstrated that the gauge field possesses the `scale dimensionality' d=1/2. Maxwell - Chern - Simons topologically massive gauge field theory in 2+1 dimensions is formulated in the first-order formalism. It is shown that 6x6-matrices of the relativistic wave equation obey the Duffin - Kemmer - Petiau algebra. The Hermitianizing matrix of the relativistic wave equation is given. The projection operators extracting solutions of field equations for states with definite energy-momentum and spin are obtained. The 5x5-matrix Schrodinger form of the equation is derived after the exclusion of non-dynamical components, and the quantum-mechanical Hamiltonian is obtained. Projection operators extracting physical states in the Schrodinger picture are found.Comment: 18 pages, correction in Ref. [5

    Interpolating Action for Strings and Membranes - a Study of Symmetries in the Constrained Hamiltonian Approach

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    A master action for bosonic strings and membranes, interpolating between the Nambu--Goto and Polyakov formalisms, is discussed. The role of the gauge symmetries vis-\`{a}-vis reparametrization symmetries of the various actions is analyzed by a constrained Hamiltonian approach. This analysis reveals the difference between strings and higher branes, which is essentially tied to a degree of freedom count. The cosmological term for membranes follows naturally in this scheme. The conncetion of our aproach with the Arnowitt--Deser--Misner representation in general relativity is illuminated.Comment: LaTex, 23 pages; discussion on ADM representation included and new references adde

    Kohn condition and exotic Newton-Hooke symmetry in the non-commutative Landau problem

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    NN "exotic" [alias non-commutative] particles with masses mam_a, charges eae_a and non-commutative parameters őła\theta_a, moving in a uniform magnetic field BB, separate into center-of-mass and internal motions if Kohn's condition e_a/m_a=\const is supplemented with e_a\theta_a=\const. Then the center-of-mass behaves as a single exotic particle carrying the total mass and charge of the system, MM and ee, and a suitably defined non-commutative parameter őė\Theta. For vanishing electric field off the critical case eőėB‚Ȇ1e\Theta B\neq1, the particles perform the usual cyclotronic motion with modified but equal frequency. The system is symmetric under suitable time-dependent translations which span a (4+2)- parameter centrally extended subgroup of the "exotic" [i.e., two-parameter centrally extended] Newton-Hooke group. In the critical case B=Bc=(eőė)‚ąí1B=B_c=(e\Theta)^{-1} the system is frozen into a static "crystal" configuration. Adding a constant electric field, all particles perform, collectively, a cyclotronic motion combined with a drift perpendicular to the electric field when eőėB‚Ȇ1e\Theta B\neq1. For B=BcB=B_c the cyclotronic motion is eliminated and all particles move, collectively, following the Hall law. Our time-dependent symmetries are reduced to the (2+1)-parameter Heisenberg group of centrally-extended translations.Comment: 12 pages, no figures. A minor error and some typos corrected, one reference adde

    Time dependent solitons of noncommutative Chern-Simons theory coupled to scalar fields

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    We study one- and two-soliton solutions of noncommutative Chern-Simons theory coupled to a nonrelativistic or a relativistic scalar field. In the nonrelativistic case, we find a tower of new stationary time-dependent solutions, all with the same charge density, but with increasing energies. The dynamics of these solitons cannot be studied using traditional moduli space techniques, but we do find a nontrivial symplectic form on the phase space indicating that the moduli space is not flat. In the relativistic case we find the metric on the two soliton moduli space.Comment: 22 pages, 2 figures, JHEP3 style. v2: This paper is a thoroughly revised version. We thank P.A. Horvathy, L. Martina and P.C. Stichel for illuminating comments that led us to reconsider some of our previously reported results; see note added at the end of the paper. v3: Acknowledgements adde

    Acceleration-Enlarged Symmetries in Nonrelativistic Space-Time with a Cosmological Constant

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    By considering the nonrelativistic limit of de-Sitter geometry one obtains the nonrelativistic space-time with a cosmological constant and Newton-Hooke (NH) symmetries. We show that the NH symmetry algebra can be enlarged by the addition of the constant acceleration generators and endowed with central extensions (one in any dimension (D) and three in D=(2+1)). We present a classical Lagrangian and Hamiltonian framework for constructing models quasi-invariant under enlarged NH symmetries which depend on three parameters described by three nonvanishing central charges. The Hamiltonian dynamics then splits into external and internal sectors with new non-commutative structures of external and internal phase spaces. We show that in the limit of vanishing cosmological constant the system reduces to the one presented in [1] which possesses accelaration-enlarged Galilean symmetries.Comment: 13 pages; small changes like a couple of footnotes et

    Non-commutative oscillator with Kepler-type dynamical symmetry

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    A 3-dimensional non-commutative oscillator with no mass term but with a certain momentum-dependent potential admits a conserved Runge-Lenz vector, derived from the dual description in momentum space. The latter corresponds to a Dirac monopole with a fine-tuned inverse-square plus Newtonian potential, introduced by McIntosh, Cisneros, and by Zwanziger some time ago. The trajectories are (arcs of) ellipses, which, in the commutative limit, reduce to the circular hodographs of the Kepler problem. The dynamical symmetry allows for an algebraic determination of the bound-state spectrum and actually extends to the conformal algebra o(4,2).Comment: 10 pages, 3 figures. Published versio

    Super-extended noncommutative Landau problem and conformal symmetry

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    A supersymmetric spin-1/2 particle in the noncommutative plane, subject to an arbitrary magnetic field, is considered, with particular attention paid to the homogeneous case. The system has three different phases, depending on the magnetic field. Due to supersymmetry, the boundary critical phase which separates the sub- and super-critical cases can be viewed as a reduction to the zero-energy eigensubspace. In the sub-critical phase the system is described by the superextension of exotic Newton-Hooke symmetry, combined with the conformal so(2,1) ~ su(1,1) symmetry; the latter is changed into so(3) ~ su(2) in the super-critical phase. In the critical phase the spin degrees of freedom are frozen and supersymmetry disappears.Comment: 12 pages, references added, published versio

    The non-linear Schr\"odinger equation and the conformal properties of non-relativistic space-time

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    The cubic non-linear Schr\"odinger equation where the coefficient of the nonlinear term is a function F(t,x)F(t,x) only passes the Painlev\'e test of Weiss, Tabor, and Carnevale only for F=(a+bt)‚ąí1F=(a+bt)^{-1}, where aa and bb are constants. This is explained by transforming the time-dependent system into the constant-coefficient NLS by means of a time-dependent non-linear transformation, related to the conformal properties of non-relativistic space-time. A similar argument explains the integrability of the NLS in a uniform force field or in an oscillator background.Comment: Thoroughly revised version, in the light of new interest in non-relativistic conformal tranformation, with a new reference list. 8 pages, LaTex, no figures. To be published in Int. J. Theor. Phy

    Landau Analog Levels for Dipoles in the Noncommutative Space and Phase Space

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    In the present contribution we investigate the Landau analog energy quantization for neutral particles, that possesses a nonzero permanent magnetic and electric dipole moments, in the presence of an homogeneous electric and magnetic external fields in the context of the noncommutative quantum mechanics. Also, we analyze the Landau--Aharonov--Casher and Landau--He--McKellar--Wilkens quantization due to noncommutative quantum dynamics of magnetic and electric dipoles in the presence of an external electric and magnetic fields and the energy spectrum and the eigenfunctions are obtained. Furthermore, we have analyzed Landau quantization analogs in the noncommutative phase space, and we obtain also the energy spectrum and the eigenfunctions in this context.Comment: 20 pages, references adde
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