546 research outputs found

    Towards a quantum field theory of primitive string fields

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    We denote generating functions of massless even higher spin fields "primitive string fields" (PSF's). In an introduction we present the necessary definitions and derive propagators and currents of these PDF's on flat space. Their off-shell cubic interaction can be derived after all off-shell cubic interactions of triplets of higher spin fields have become known [2],[3]. Then we discuss four-point functions of any quartet of PSF's. In subsequent sections we exploit the fact that higher spin field theories in AdSd+1AdS_{d+1} are determined by AdS/CFT correspondence from universality classes of critical systems in dd dimensional flat spaces. The O(N) invariant sectors of the O(N) vector models for 1≀N≀∞1\leq N \leq \infty play for us the role of "standard models", for varying NN, they contain e.g. the Ising model for N=1 and the spherical model for N=∞N=\infty. A formula for the masses squared that break gauge symmetry for these O(N) classes is presented for d = 3. For the PSF on AdSAdS space it is shown that it can be derived by lifting the PSF on flat space by a simple kernel which contains the sum over all spins. Finally we use an algorithm to derive all symmetric tensor higher spin fields. They arise from monomials of scalar fields by derivation and selection of conformal (quasiprimary) fields. Typically one monomial produces a multiplet of spin ss conformal higher spin fields for all s≄4s \geq 4, they are distinguished by their anomalous dimensions (in CFT3CFT_3) or by their mass (in AdS4AdS_4). We sum over these multiplets and the spins to obtain "string type fields", one for each such monomial.Comment: 16 pages,Late

    Supersymmetric Distributions, Hilbert Spaces of Supersymmetric Functions and Quantum Fields

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    The recently investigated Hilbert-Krein and other positivity structures of the superspace are considered in the framework of superdistributions. These tools are applied to problems raised by the rigorous supersymmetric quantum field theory.Comment: 24 page

    Local Interactions of Higher-Spin Potentials That are Gauge Invariant in Linear Approximation

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    We study connected Wightman functions of NN conserved currents, each of which is formed from a scalar field and has even spin lil_{i}. The UV divergence of this vertex function is regularized by the analytic continuation in the space dimension D⟶D−ϔD\longrightarrow D-\epsilon. We evaluate the residue of ϔ−1\epsilon ^{-1} only, which is a local interaction Lagrangian density and gauge invariant in linearComment: Talk given at Group XXVII Yerevan, Armenia, August 13-29, 2008, v.2 published in Yadernaya Fizika 73 (2010) 518-52

    Structural motifs of pre-nucleation clusters

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    Structural motifs of pre-nucleation clusters prepared in single, optically levitated supersaturated aqueous aerosol microparticles containing CaBr2 as a model system are reported. Cluster formation is identified by means of X-ray absorption in the Br K-edge regime. The salt concentration beyond the saturation point is varied by controlling the humidity in the ambient atmosphere surrounding the 15–30 ÎŒm microdroplets. This leads to the formation of metastable supersaturated liquid particles. Distinct spectral shifts in near-edge spectra as a function of salt concentration are observed, in which the energy position of the Br K-edge is red-shifted by up to 7.1 ± 0.4 eV if the dilute solution is compared to the solid. The K-edge positions of supersaturated solutions are found between these limits. The changes in electronic structure are rationalized in terms of the formation of pre- nucleation clusters. This assumption is verified by spectral simulations using first-principle density functional theory and molecular dynamics calculations, in which structural motifs are considered, explaining the experimental results. These consist of solvated CaBr2 moieties, rather than building blocks forming calcium bromide hexahydrates, the crystal system that is formed by drying aqueous CaBr2 solutions

    Steroid concentrations in atopic dermatitis patients: Reduced plasma DHEAS and increased cortisone levels.

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    Atopic dermatitis (AD) is a chronically relapsing inflammatory skin disease, which is characterized by a disrupted epidermal barrier function present both in affected skin and in non-affected skin. Mainly glucocorticosteroids were used in topical and systemic atopy treatments because of their potent anti-inflammatory effects, unfortunately with strong side effects. In this study we determined that 2 out of 16 steroids were significantly different in healthy volunteers vs AD-patients. Cortisone, which is higher in AD-patients plasma, is a direct precursor of the bioactive corticosteroid cortisol, which just displays a higher tendency and is known for its potent anti-inflammatory effects. In addition a tendency of reduced levels of the anti-inflammatory ER ligand estrone was found in AD-patients. DHEA is a precursor of testosterone, its levels just display a lower tendency in male AD-patients, while its sulfonation metabolite DHEAS is lower in male and female AD-patients. We found and conclude that altered steroid levels in the plasma of AD-patients indicate altered vitamin D signaling (based on reduced DHEA sulfonation) and increased feedback for anti-inflammatory signaling (increased levels of cortisone) present in AD-patients. This article is protected by copyright. All rights reserved

    Gravitation on a Homogeneous Domain

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    Among all plastic deformations of the gravitational Lorentz vacuum \cite{wr1} a particular role is being played by conformal deformations. These are conveniently described by using the homogeneous space for the conformal group SU(2,2)/S(U(2)x U(2)) and its Shilov boundary - the compactified Minkowski space \tilde{M} [1]. In this paper we review the geometrical structure involved in such a description. In particular we demonstrate that coherent states on the homogeneous Kae}hler domain give rise to Einstein-like plastic conformal deformations when extended to \tilde{M} [2].Comment: 10 pages, 1 figure; four misprints in the original version corrected: one lacking closing parenthesis, two letters, and an overall sign in front of the primitive function on p.

    Multiple algebraisations of an elliptic Calogero-Sutherland model

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    Recently, Gomez-Ullate et al. (1) have studied a particular N-particle quantum problem with an elliptic function potential supplemented by an external field. They have shown that the Hamiltonian operator preserves a finite dimensional space of functions and as such is quasi exactly solvable (QES). In this paper we show that other types of invariant function spaces exist, which are in close relation to the algebraic properties of the elliptic functions. Accordingly, series of new algebraic eigenfunctions can be constructed.Comment: 9 Revtex pages, 3 PS-figures; Summary, abstract and conclusions extende

    Untersuchungen zum Gaswechsel der Rebe I. Einfluß von Temperatur, Blattalter und Tageszeit auf Nettophotosynthese und Transpiration

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    An verschiedenen Rebsorten wurde unter Laborbedingungen (30 klx, 50 % ) der Einfluß von Temperatur, Blattalter und Tageszeit auf die Nettophotosyntheserate (NPR) und Transpirationsrate (TR) an GewĂ€chshauspflanzen ermittelt. Das Optimum der NPR lag bei 25 °C, wĂ€hrend die TR von 10 °C bis 30 °C annĂ€hernd linear anstieg.Die höchste NPR hatten gerade ausgewachsene BlĂ€tter; Ă€ltere BlĂ€tter zeigten eine etwas geringere, jĂŒngere eine deutlich verminderte NPR. Die VerhĂ€ltnisse bei der TR waren Ă€hnlich, aber weniger ausgeprĂ€gt und zu den jĂŒngeren BlĂ€ttern hin verschoben.Bei trocken kultivierten Pflanzen kam es im Laufe des Tages zu einer starken Reduktion der NPR and TR um etwa 2/a der Werte des Vormittags, nicht dagegen bei ausreichender Wasserversorgung.Investigations on gas exchange in grapevine I. Influence of temperature, leaf age and daytime on net photosynthesis and transpirationThe influence of temperature, leaf age and daytime on the rates of net photosynthesis and transpiration was measured under constant environmental conditions in greenhouse-grown plants of different varieties.The temperature optimum of net photosynthesis was at 25 °C whereas transpiration increased nearly linear from 10 °C to 30 °C.The highest rates of net photosynthesis possessed just fully grown leaves; older leaves showed a minor, younger leaves a more pronounced reduction. The pattern of transpiration rates was nearly the same, but not that distinct.Plants grown under drought conditions reduced their rates of net photosynthesis and transpiration during daytime very strongly (by 2/3 of the rates early in the morning). whereas in watered plants this influence could not be observed
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