1,633 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
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
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
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
The homotopy theory of simplicial props
The category of (colored) props is an enhancement of the category of colored
operads, and thus of the category of small categories. In this paper, the
second in a series on "higher props," we show that the category of all small
colored simplicial props admits a cofibrantly generated model category
structure. With this model structure, the forgetful functor from props to
operads is a right Quillen functor.Comment: Final version, to appear in Israel J. Mat
A colimit decomposition for homotopy algebras in Cat
Badzioch showed that in the category of simplicial sets each homotopy algebra
of a Lawvere theory is weakly equivalent to a strict algebra. In seeking to
extend this result to other contexts Rosicky observed a key point to be that
each homotopy colimit in simplicial sets admits a decomposition into a homotopy
sifted colimit of finite coproducts, and asked the author whether a similar
decomposition holds in the 2-category of categories Cat. Our purpose in the
present paper is to show that this is the case.Comment: Some notation changed; small amount of exposition added in intr
The self-consistent bounce: an improved nucleation rate
We generalize the standard computation of homogeneous nucleation theory at
zero temperature to a scenario in which the bubble shape is determined
self-consistently with its quantum fluctuations. Studying two scalar models in
1+1 dimensions, we find the self-consistent bounce by employing a two-particle
irreducible (2PI) effective action in imaginary time at the level of the
Hartree approximation. We thus obtain an effective single bounce action which
determines the rate exponent. We use collective coordinates to account for the
translational invariance and the growth instability of the bubble and finally
present a new nucleation rate prefactor. We compare the results with those
obtained using the standard 1-loop approximation and show that the
self-consistent rate can differ by several orders of magnitude.Comment: 28 pages, revtex, 7 eps figure
Strongly absorbed quiescent X-ray emission from the X-ray transient XTE J0421+56 (CI Cam) observed with XMM-Newton
We have observed the X-ray transient XTE J0421+56 in quiescence with
XMM-Newton. The observed spectrum is highly unusual being dominated by an
emission feature at ~6.5 keV. The spectrum can be fit using a partially covered
power-law and Gaussian line model, in which the emission is almost completely
covered (covering fraction of 0.98_{-0.06}^{+0.02}) by neutral material and is
strongly absorbed with an N_H of (5_{-2}^{+3}) x 10^{23} atom cm^{-2}. This
absorption is local and not interstellar. The Gaussian has a centroid energy of
6.4 +/- 0.1 keV, a width < 0.28 keV and an equivalent width of 940
^{+650}_{-460} eV. It can be interpreted as fluorescent emission line from
iron. Using this model and assuming XTE J0421+56 is at a distance of 5 kpc, its
0.5-10 keV luminosity is 3.5 x 10^{33} erg s^{-1}. The Optical Monitor onboard
XMM-Newton indicates a V magnitude of 11.86 +/- 0.03. The spectra of X-ray
transients in quiescence are normally modeled using advection dominated
accretion flows, power-laws, or by the thermal emission from a neutron star
surface. The strongly locally absorbed X-ray emission from XTE J0421+56 is
therefore highly unusual and could result from the compact object being
embedded within a dense circumstellar wind emitted from the supergiant B[e]
companion star. The uncovered and unabsorbed component observed below 5 keV
could be due either to X-ray emission from the supergiant B[e] star itself, or
to the scattering of high-energy X-ray photons in a wind or ionized corona,
such as observed in some low-mass X-ray binary systems.Comment: 8 pages, 4 postscript figures, accepted for publication in Astronomy
and Astrophysic
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