1,194 research outputs found

    Geons of Galileons

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    We suggest that galileon theories should have an additional self-coupling of the fields to the trace of their own energy-momentum tensor. We explore the classical features of one such model, in flat 4D spacetime, with emphasis on solutions that are scalar analogues of gravitational geons. We discuss the stability of these scalar geons, and some of their possible signatures, including shock fronts.Comment: References added in v

    Euler Incognito

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    The nonlinear flow equations discussed recently by Bender and Feinberg are all reduced to the well-known Euler equation after change of variables.Comment: 2 page

    A universal solution

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    The phenomenon of an implicit function which solves a large set of second order partial differential equations obtainable from a variational principle is explicated by the introduction of a class of universal solutions to the equations derivable from an arbitrary Lagrangian which is homogeneous of weight one in the field derivatives. This result is extended to many fields. The imposition of Lorentz invariance makes such Lagrangians unique, and equivalent to the Companion Lagrangians introduced in [baker].Comment: arxiv version is already officia

    A Compact Formula for Rotations as Spin Matrix Polynomials

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    Group elements of SU(2) are expressed in closed form as finite polynomials of the Lie algebra generators, for all definite spin representations of the rotation group. The simple explicit result exhibits connections between group theory, combinatorics, and Fourier analysis, especially in the large spin limit. Salient intuitive features of the formula are illustrated and discussed

    Ternary Virasoro - Witt Algebra

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    A 3-bracket variant of the Virasoro-Witt algebra is constructed through the use of su(1,1) enveloping algebra techniques. The Leibniz rules for 3-brackets acting on other 3-brackets in the algebra are discussed and verified in various situations.Comment: 6 pages, Late

    Hyper-elliptic Nambu flow associated with integrable maps

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    We study hyper-elliptic Nambu flows associated with some nn dimensional maps and show that discrete integrable systems can be reproduced as flows of this class.Comment: 13 page

    Wigner Trajectory Characteristics in Phase Space and Field Theory

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    Exact characteristic trajectories are specified for the time-propagating Wigner phase-space distribution function. They are especially simple---indeed, classical---for the quantized simple harmonic oscillator, which serves as the underpinning of the field theoretic Wigner functional formulation introduced. Scalar field theory is thus reformulated in terms of distributions in field phase space. Applications to duality transformations in field theory are discussed.Comment: 9 pages, LaTex2

    Focus on adolescents with HIV and AIDS

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    KMAdolescents living with HIV, including those infected perinatally and non-perinatally, bear a disproportionate burden of the HIV epidemic in South Africa. This article discusses HIV management in adolescents including the following aspects: (i) burden of HIV disease, modes of HIV acquisition and implications for management; (ii) initiation of combination antiretroviral therapy (ART), outcomes and complications of ART in adolescents,including virological failure and switching regimens; (iii) adherence in adolescence, including factors that may contribute to poor adherence and advice to improve adherence; (iv) issues particular to adolescents, including sexual and reproductive health needs, disclosure to adolescents and by adolescents, and transition to adult care. This article aims to provide insights based on the literature and experience to assist the clinician to navigate the difficulties of managing HIV in adolescence and achieving successful transition to adult care
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