12,026 research outputs found

    Homogeneous geodesics of non-unimodular Lorentzian Lie groups and naturally reductive Lorentzian spaces in dimension three

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    We determine, for all three-dimensional non-unimodular Lie groups equipped with a Lorentzian metric, the set of homogeneous geodesics through a point. Together with the results of [C] and [CM2], this leads to the full classification of three-dimensional Lorentzian g.o. spaces and naturally reductive spaces

    Coherent states for the q-deformed quantum mechanics on a circle

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    The q-deformed coherent states for a quantum particle on a circle are introduced and their properties investigated.Comment: 11 pages, 2 PostScript figure

    Planck-scale relativity from quantum κ\kappa-Poincar\'e algebra

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    Extending the commutator algebra of quantum κ\kappa-Poincar\'e symmetry to the whole of the phase space, and assuming that this algebra is to be covariant under action of deformed Lorentz generators, we derive the transformation properties of positions under the action of deformed boosts. It turns out that these transformations leave invariant the quadratic form in the position space, which is the Minkowski metric and that the boosts saturate. The issues of massless and massive particles motion, as well as time dilatation and length contraction in this new framework are also studied.Comment: 14 pages, LaTeX, no figure

    A Survey of the Management and Development of Captive African Elephant (\u3cem\u3eLoxodonta africana\u3c/em\u3e) Calves: Birth to Three Months of Age

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    We used four surveys to collect information about the birth, physical growth, and behavioral development of 12 African elephant calves born in captivity. The management of the birth process and neonatal care involved a variety of standard procedures. All of the calves were born at night, between 7PM and 7AM. The calves showed a systematic progression in behavioral and physical development, attaining developmental milestones at least a quickly as calves in situ. This study emphasized birth-related events, changes in the ways that calves used their trunks, first instances of behaviors, and interactions of the calves with other, usually adult, elephants. Several behaviors, such as the dam covering her calf with hay and the calf sucking its own trunk, were common in the captive situation and have been observed in situ. Overall, the behaviors of the calves resembled those observed for African elephant calves in situ. These data should help in the management of African elephants under human care by providing systematic reference values for the birth and development of elephant calves

    The Behaviour of the Green Function for the BFKL Pomeron with Running Coupling

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    We analyse here in LO the physical properties of the Green function solution for the BFKL equation. We show that the solution obeys the orthonormality conditions in the physical region and fulfills the completeness requirements. The unintegrated gluon density is shown to consists of a set of few poles with parameters which could be determined by comparison with the DIS data of high precision

    Indirect Evidence for New Physics at the 10 TeV Scale

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    We show that the supersymmetric extension of the Standard Model modifies the structure of the low lying BFKL discrete pomeron states (DPS) which give a sizable contribution to the gluon structure function in the HERA x and Q2 region. The comparison of the gluon density, determined within DPS with N=1 SUSY, with data favours a supersymmetry scale of the order of 10 TeV. The DPS method described here could open a new window to the physics beyond the Standard Model.Comment: 14 pages, 6 figure

    Scalar field theory on κ\kappa-Minkowski space-time and Doubly Special Relativity

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    In this paper we recall the construction of scalar field action on κ\kappa-Minkowski space-time and investigate its properties. In particular we show how the co-product of κ\kappa-Poincar\'e algebra of symmetries arises from the analysis of the symmetries of the action, expressed in terms of Fourier transformed fields. We also derive the action on commuting space-time, equivalent to the original one. Adding the self-interaction Φ4\Phi^4 term we investigate the modified conservation laws. We show that the local interactions on κ\kappa-Minkowski space-time give rise to 6 inequivalent ways in which energy and momentum can be conserved at four-point vertex. We discuss the relevance of these results for Doubly Special Relativity.Comment: 17 pages; some editing done, final version to be published in Int. J. Mod. Phys.

    Tsallis' deformation parameter q quantifies the classical-quantum transition

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    We investigate the classical limit of a type of semiclassical evolution, the pertinent system representing the interaction between matter and a given field. On using as a quantifier of the ensuing dynamics Tsallis q-entropy, we encounter that it not only appropriately describes the quantum-classical transition, but that the associated deformation-parameter q itself characterizes the different regimes involved in the process, detecting the most salient fine details of the changeover.Comment: 19 pages, 7 figure

    Relative Locality in κ\kappa-Poincar\'e

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    We show that the κ\kappa-Poincar\'e Hopf algebra can be interpreted in the framework of curved momentum space leading to the relativity of locality \cite{AFKS}. We study the geometric properties of the momentum space described by κ\kappa-Poincar\'e, and derive the consequences for particles propagation and energy-momentum conservation laws in interaction vertices, obtaining for the first time a coherent and fully workable model of the deformed relativistic kinematics implied by κ\kappa-Poincar\'e. We describe the action of boost transformations on multi-particles systems, showing that in order to keep covariant the composed momenta it is necessary to introduce a dependence of the rapidity parameter on the particles momenta themselves. Finally, we show that this particular form of the boost transformations keeps the validity of the relativity principle, demonstrating the invariance of the equations of motion under boost transformations.Comment: 24 pages, 4 figures, 1 table. v2 matches accepted CQG versio
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