1,365 research outputs found

    Phase structure of the N=1 supersymmetric Yang-Mills theory at finite temperature

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    Supersymmetry (SUSY) has been proposed to be a central concept for the physics beyond the standard model and for a description of the strong interactions in the context of the AdS/CFT correspondence. A deeper understanding of these developments requires the knowledge of the properties of supersymmetric models at finite temperatures. We present a Monte Carlo investigation of the finite temperature phase diagram of the N=1 supersymmetric Yang-Mills theory (SYM) regularised on a space-time lattice. The model is in many aspects similar to QCD: quark confinement and fermion condensation occur in the low temperature regime of both theories. A comparison to QCD is therefore possible. The simulations show that for N=1 SYM the deconfinement temperature has a mild dependence on the fermion mass. The analysis of the chiral condensate susceptibility supports the possibility that chiral symmetry is restored near the deconfinement phase transition.Comment: 26 pages, 12 figure

    N=1 supersymmetric Yang-Mills theory on the lattice

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    Numerical simulations of supersymmetric theories on the lattice are intricate and challenging with respect to their theoretical foundations and algorithmic realisation. Nevertheless, the simulations of a four-dimensional supersymmetric gauge theory have made considerable improvements over the recent years. In this contribution we summarise the results of our collaboration concerning the mass spectrum of this theory. The investigation of systematic errors allows now a more precise estimate concerning the expected formation of supersymmetric multiplets of the lightest particles. These multiplets contain flavour singlet mesons, glueballs, and an additional fermionic state.Comment: presented at the 31st International Symposium on Lattice Field Theory (Lattice 2013), 29 July - 3 August 2013, Mainz, German

    Subkutane Dirofilariasis: Infektion mit Dirofilaria repens.

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    A female patient resident in Germany is described, who had developed dirofilariasis presenting as a hard subcutaneous nodule at the glabella. Dirofilaria repens was isolated after surgical removal of the skin lesion. She was treated with diethylcarbamazine (Hetrazan) for 4 weeks. Exposures related to infection with Dirofilaria repens are discussed

    On the estimation of brain signal entropy from sparse neuroimaging data

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    Multi-scale entropy (MSE) has been recently established as a promising tool for the analysis of the moment-to-moment variability of neural signals. Appealingly, MSE provides a measure of the predictability of neural operations across the multiple time scales on which the brain operates. An important limitation in the application of the MSE to some classes of neural signals is MSE’s apparent reliance on long time series. However, this sparse-data limitation in MSE computation could potentially be overcome via MSE estimation across shorter time series that are not necessarily acquired continuously (e.g., in fMRI block-designs). In the present study, using simulated, EEG, and fMRI data, we examined the dependence of the accuracy and precision of MSE estimates on the number of data points per segment and the total number of data segments. As hypothesized, MSE estimation across discontinuous segments was comparably accurate and precise, despite segment length. A key advance of our approach is that it allows the calculation of MSE scales not previously accessible from the native segment lengths. Consequently, our results may permit a far broader range of applications of MSE when gauging moment-to- moment dynamics in sparse and/or discontinuous neurophysiological data typical of many modern cognitive neuroscience study designs

    Group actions on Segal operads

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    We give a Quillen equivalence between model structures for simplicial operads, described via the theory of operads, and Segal operads, thought of as certain reduced dendroidal spaces. We then extend this result to give an Quillen equivalence between the model structures for simplicial operads equipped with a group action and the corresponding Segal operads.Comment: Revised version. Accepted to Isr J Mat

    Dressing Up the Kink

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    Many quantum field theoretical models possess non-trivial solutions which are stable for topological reasons. We construct a self-consistent example for a self-interacting scalar field--the quantum (or dressed) kink--using a two particle irreducible effective action in the Hartree approximation. This new solution includes quantum fluctuations determined self-consistently and nonperturbatively at the 1-loop resummed level and allowed to backreact on the classical mean-field profile. This dressed kink is static under the familiar Hartree equations for the time evolution of quantum fields. Because the quantum fluctuation spectrum is lower lying in the presence of the defect, the quantum kink has a lower rest energy than its classical counterpart. However its energy is higher than well-known strict 1-loop results, where backreaction and fluctuation self-interactions are omitted. We also show that the quantum kink exists at finite temperature and that its profile broadens as temperature is increased until it eventually disappears.Comment: 13 pages, latex, 3 eps figures; revised with yet additional references, minor rewordin

    Bubble formation in Ď•6\phi^6 potential

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    Scalar field theory with an asymmetric potential is studied at zero temperature and high-temperature for Ď•6\phi^6 potential. The equations of motion are solved numerically to obtain O(4) spherical symmetric and O(3) cylindrical symmetric bounce solutions. These solutions control the rates for tunneling from the false vacuum to the true vacuum by bubble formation. The range of validity of the thin-wall approximation (TWA) is investigated. An analytical solution for the bounce is presented, which reproduces the action in the thin-wall as well as the thick-wall limits.Comment: 22 pag

    Navigating the Accounting Academic Job Market and Related Advice

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    Purpose: To disseminate helpful advice to current and future candidates about the accounting academic job market. Methodology/Approach: Literature review, interviews with recently hired faculty members, insights from the author’s experiences as both job candidates and search committee members, and discussions with colleagues. Findings: In this chapter, we discuss the current state of the job market for accounting professors and offer our insights as well as those from a group of recent graduates. It is our recent experience that many rookie candidates pursue initial faculty positions with an incomplete understanding of many aspects of the market, including how the market clears, job expectations, and other issues that we believe are important. While others have adequately addressed the importance of research in the profession and alluded to some aspects of the market, we provide additional useful information about the market and other career aspects in order to assist new graduates in their quests to find fulfilling appointments. Our chapter complements existing literature to form an updated and more complete picture of the market and profession. Practical Implications: This chapter helps prepare candidates for the job market by providing information and advice that complements advice given in Ph.D. programs and the existing literature. Social Implications: Candidates entering the job market will better understand the nuances of the market and can make more informed decisions about the institutions that best meet their needs. Originality/Value of Article: The chapter provides important practical advice for job seekers about the accounting academic job market not available elsewhere

    Towers and fibered products of model categories

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    Given a left Quillen presheaf of localized model structures, we study the homotopy limit model structure on the associated category of sections. We focus specifically on towers and fibered products of model categories. As applications we consider Postnikov towers of model categories, chromatic towers of spectra and Bousfield arithmetic squares of spectra. For spectral model categories, we show that the homotopy fiber of a stable left Bousfield localization is a stable right Bousfield localization

    Homological Localisation of Model Categories

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    One of the most useful methods for studying the stable homotopy category is localising at some spectrum E. For an arbitrary stable model category we introduce a candidate for the E–localisation of this model category. We study the properties of this new construction and relate it to some well–known categories
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