187 research outputs found

    One-particle reducible contribution to the one-loop spinor propagator in a constant field

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    Extending work by Gies and Karbstein on the Euler\ue2\u80\u93Heisenberg Lagrangian, it has recently been shown that the one-loop propagator of a charged scalar particle in a constant electromagnetic field has a one-particle reducible contribution in addition to the well-studied irreducible one. Here we further generalize this result to the spinor case, and find the same relation between the reducible term, the tree-level propagator and the one-loop Euler\ue2\u80\u93Heisenberg Lagrangian as in the scalar case. Our demonstration uses a novel worldline path integral representation of the photon-dressed spinor propagator in a constant electromagnetic field background

    Publication and patent analysis of European researchers in the field of production technology and manufacturing systems

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    This paper develops a structured comparison among a sample of European researchers in the field of Production Technology and Manufacturing Systems, on the basis of scientific publications and patents. Researchers are evaluated and compared by a variegated set of indicators concerning (1) the output of individual researchers and (2) that of groups of researchers from the same country. While not claiming to be exhaustive, the results of this preliminary study provide a rough indication of the publishing and patenting activity of researchers in the field of interest, identifying (dis)similarities between different countries. Of particular interest is a proposal for aggregating analysis results by means of maps based on publication and patent indicators. A large amount of empirical data are presented and discusse

    Bosonic Quadratic Actions for 11D Supergravity on AdS_7/4 x S_4/7

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    We determine from 11D supergravity the quadratic bulk action for the physical bosonic fields relevant for the computation of correlation functions of normalized chiral operators in D=6, N=(0,2) and D=3, N=8 supersymmetric CFT in the large N limit, as dictated by the AdS/CFT duality conjecture.Comment: 16 pages, Plain TeX, no figures, requires AMS font files amssym.def and amssym.tex, a few typos correcte

    SCN1B gene variants in Brugada Syndrome: a study of 145 SCN5A-negative patients.

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    Brugada syndrome is characterised by a typical ECG with ST segment elevation in the right precordial leads. Individuals with this condition are susceptible to ventricular arrhythmias and sudden cardiac death. The principal gene responsible for this syndrome is SCN5A, which encodes the α-subunit of the Nav1.5 voltage-gated sodium channel. Mutations involving other genes have been increasingly reported, but their contribution to Brugada syndrome has been poorly investigated. Here we focused on the SCN1B gene, which encodes the β1-subunit of the voltage-gated sodium channel and its soluble β1b isoform. SCN1B mutations have been associated with Brugada syndrome as well as with other cardiac arrhythmias and familial epilepsy. In this study, we have analysed SCN1B exons (including the alternatively-spliced exon 3A) and 3′UTR in 145 unrelated SCN5A-negative patients from a single centre. We took special care to report all identified variants (including polymorphisms), following the current nomenclature guidelines and considering both isoforms. We found two known and two novel (and likely deleterious) SCN1B variants. We also found two novel changes with low evidence of pathogenicity. Our findings contribute more evidence regarding the occurrence of SCN1B variants in Brugada syndrome, albeit with a low prevalence, which is in agreement with previous reports

    Detours and Paths: BRST Complexes and Worldline Formalism

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    We construct detour complexes from the BRST quantization of worldline diffeomorphism invariant systems. This yields a method to efficiently extract physical quantum field theories from particle models with first class constraint algebras. As an example, we show how to obtain the Maxwell detour complex by gauging N=2 supersymmetric quantum mechanics in curved space. Then we concentrate on first class algebras belonging to a class of recently introduced orthosymplectic quantum mechanical models and give generating functions for detour complexes describing higher spins of arbitrary symmetry types. The first quantized approach facilitates quantum calculations and we employ it to compute the number of physical degrees of freedom associated to the second quantized, field theoretical actions.Comment: 1+35 pages, 1 figure; typos corrected and references added, published versio
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