1,397 research outputs found
Phase structure of the N=1 supersymmetric Yang-Mills theory at finite temperature
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
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.
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
Group actions on Segal operads
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
On the estimation of brain signal entropy from sparse neuroimaging data
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
Dressing Up the Kink
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 potential
Scalar field theory with an asymmetric potential is studied at zero
temperature and high-temperature for 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
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
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
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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