2,242 research outputs found

    DAMA detection claim is still compatible with all other DM searches

    Full text link
    We show that the annual modulation signal observed by DAMA can be reconciled with all other negative results from dark matter searches with a conventional halo model for particle masses around 5 to 9 GeV. We also show which particular dark matter stream could produce the DAMA signal.Comment: Talk given at TAUP2005, Sept. 10-14 2005, Zaragoza (Spain). 3 pages, 4 figure

    Positioning systems in Minkowski space-time: from emission to inertial coordinates

    Full text link
    The coordinate transformation between emission coordinates and inertial coordinates in Minkowski space-time is obtained for arbitrary configurations of the emitters. It appears that a positioning system always generates two different coordinate domains, namely, the front and the back emission coordinate domains. For both domains, the corresponding covariant expression of the transformation is explicitly given in terms of the emitter world-lines. This task requires the notion of orientation of an emitter configuration. The orientation is shown to be computable from the emission coordinates for the users of a `central' region of the front emission coordinate domain. Other space-time regions associated with the emission coordinates are also outlined.Comment: 20 pages; 1 figur

    On the Weyl transverse frames in type I spacetimes

    Full text link
    We apply a covariant and generic procedure to obtain explicit expressions of the transverse frames that a type I spacetime admits in terms of an arbitrary initial frame. We also present a simple and general algorithm to obtain the Weyl scalars Ψ2T\Psi_2^T, Ψ0T\Psi_0^T and Ψ4T\Psi_4^T associated with these transverse frames. In both cases it is only necessary to choose a particular root of a cubic expression.Comment: 12 pages, submitted to Gen. Rel. Grav. (6-3-2004

    Non-coboundary Poisson-Lie structures on the book group

    Full text link
    All possible Poisson-Lie (PL) structures on the 3D real Lie group generated by a dilation and two commuting translations are obtained. Its classification is fully performed by relating these PL groups with the corresponding Lie bialgebra structures on the corresponding "book" Lie algebra. By construction, all these Poisson structures are quadratic Poisson-Hopf algebras for which the group multiplication is a Poisson map. In contrast to the case of simple Lie groups, it turns out that most of the PL structures on the book group are non-coboundary ones. Moreover, from the viewpoint of Poisson dynamics, the most interesting PL book structures are just some of these non-coboundaries, which are explicitly analysed. In particular, we show that the two different q-deformed Poisson versions of the sl(2,R) algebra appear as two distinguished cases in this classification, as well as the quadratic Poisson structure that underlies the integrability of a large class of 3D Lotka-Volterra equations. Finally, the quantization problem for these PL groups is sketched.Comment: 15 pages, revised version, some references adde

    2D vs. 3D pain visualization: User preferences in a spinal cord injury cohort

    Get PDF
    This is the post-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2011 Springer VerlagResearch on pain experienced after Spinal Cord Injury (SCI) has revealed that not only are there several types of pain present in the same individual with this kind of trauma, but also that people who suffer such an injury can describe the characteristics of the same type of pain in different ways. Making it possible, therefore, to more precisely describe pain experience could prove to be vital for an increased quality of life. Accordingly, fifteen individuals with pain after SCI were asked to describe their pain experience using a 3 Dimensional (3D) model of the human body that could be used as an aid in communicating their pain. The results of this study suggest that the consensus of the participants approved the ability of the 3D model to more accurately describe their pain, an encouraging outcome towards the use of 3D technology in support of post SCI pain rehabilitation

    On the existence of Killing vector fields

    Get PDF
    In covariant metric theories of coupled gravity-matter systems the necessary and sufficient conditions ensuring the existence of a Killing vector field are investigated. It is shown that the symmetries of initial data sets are preserved by the evolution of hyperbolic systems.Comment: 9 pages, no figure, to appear in Class. Quant. Gra

    Physicochemical characterisation of restructured Fenalår and safety implications of salt and nitrite reduction

    Get PDF
    There is a new trend to produce dry-cured ham from lamb in shorter times by boning the ham before salting to later obtain restructured hams that are easier to dry and slice. However, little information about the physicochemical characteristics of Norwegian Fenalårs during the process or the safety implications of their elaboration procedures is reported in the literature. The aim of this study was to characterize the colour, texture and physicochemical properties of restructured Fenalårs when using Standard Salting (SS), Salt Reduced (SR) and a Non-Nitrite Salt Reduced (NNSR) treatments. Microbiological safety implications of the elaboration process when using the different salting treatments were also assessed using predictive microbiology. To do so, sixty Fenalårs were elaborated using a Standard Salting (SS), a Salt reduced (SR) and a Non-Nitrite Salt Reduced (NNSR) treatments. Physicochemical characterization (instrumental colour and texture and Zinc Protoporphyrin content) was performed at the end of the process using thirty Fenalårs. The rest of the Fenalårs were used to characterize the product through the elaboration process (pH and aw) for the evaluation of microbiological hazards when using the different salting treatments using predictive microbiology. Results showed a significant increase in softness when reducing salt content and a decrease of redness when no nitrite was used, attributed to the formation of ZnPP content instead of nitrosylmyoglobin. In terms of risk assessment, the decrease of aw through the elaboration process reduced the growth capacity of all the microorganisms evaluated. However, microbiological safety implications in salt reduced Fenalårs are important, especially when no nitrite was added, because the considerable increase of growth potential of L. monocytogenes. The increase of growth potential of proteolytic C. botulinum is very little and no relevant effect of nitrite on growth potential of S. aureus was observed. Predictive microbiology and optimization of the process to enhance ZnPP formation can help to ensure safety and quality of salt reduced restructured Fenalårs without additives.info:eu-repo/semantics/acceptedVersio

    Cohomology and Deformation of Leibniz Pairs

    Full text link
    Cohomology and deformation theories are developed for Poisson algebras starting with the more general concept of a Leibniz pair, namely of an associative algebra AA together with a Lie algebra LL mapped into the derivations of AA. A bicomplex (with both Hochschild and Chevalley-Eilenberg cohomologies) is essential.Comment: 15 page
    corecore