1,503 research outputs found
Geometry of good sets in n-fold Cartesian product
We propose here a multidimensional generalisation of the notion of link
introduced in our previous papers and we discuss some consequences for
simplicial measures and sums of function algebras.Comment: 17 pages, no figures, no table
Mathematics of risk taking
A simple mathematical model for an investor's gains and losses over time shows that, in the long run, those with large sums to invest have an excellent chance of reaching their goal while the marginal investors have a high probability of going bankrupt. A greedy investor, rich or poor, will hit the bottom in the long run, with probability one. Consequences for the population at large are discussed
3d SU(N) + adjoint Higgs theory and finite temperature QCD
We study to what extent the three-dimensional SU(N)+adjoint Higgs theory can
be used as an effective theory for finite temperature SU(N) gauge theory, with
N=2,3. The parameters of the 3d theory are computed in 2-loop perturbation
theory in terms of T/Lambda_MSbar,N,N_f. The perturbative effective potential
of the 3d theory is computed to two loops for N=2. While the Z(N) symmetry
probably driving the 4d confinement-deconfinement phase transition (for N_f=0)
is not explicit in the effective Lagrangian, it is partly reinstated by
radiative effects in the 3d theory. Lattice simulations in the 3d theory are
carried out for N=2, and the static screening masses relevant for the
high-temperature phase of the 4d theory are measured. In particular, we measure
non-perturbatively the O(g^2 T) correction to the Debye screening mass. We find
that non-perturbative effects are much larger in the SU(2) + adjoint Higgs
theory than in the SU(2) + fundamental Higgs theory.Comment: 30 pages, 9 figure
A Case Of Invasive Aspergillosis in a Patient with No Identifiable Immunodeficiencies
Invasive fungal infections usually affect patients with immunodeficiencies and very rarely patients with no known or identifiable risk factors. Diagnosis could be delayed in patients without previously known immunodeficiencies due to a low index of suspicion, leading to a delay in treatment and a potential poor outcome. We report a case of a postpartum woman with no history of immuno-compromised disease who developed left hemiparesis with evidence of invasive aspergollosis affecting the nervous system, and leading to fatal outcome. The patient had a mass-like lesion in the neuroimaging with soft tissue shadowing in the chest x-ray leading to initial diagnosis of tuberculosis. The brain biopsy showed changes consistent with a diagnosis of aspergillosis. The source of the aspergillus infection was not clear. Aspergillus infection should be considered in patients with no identifiable immunodeficiencies who have abnormal brain imaging and chest x-ray, as early treatment may alter the outcome
Intravascular Polarimetry: Clinical Translation and Future Applications of Catheter-Based Polarization Sensitive Optical Frequency Domain Imaging
Optical coherence tomography (OCT) and optical frequency domain imaging (OFDI)
visualize the coronary artery wall and plaque morphology in great detail. The advent of
these high-resolution intracoronary imaging modalities has propelled our understanding
of coronary atherosclerosis and provided enhanced guidance for percutaneous coronary
intervention. Yet, the lack of contrast between distinct tissue types and plaque
compositions impedes further elucidation of the complex mechanisms that contribute
to acute coronary syndrome (ACS) and hinders the prospective identification of
plaques susceptible to rupture. Intravascular polarimetry with polarization-sensitive
OFDI measures polarization properties of the coronary arterial wall using conventional
intravascular imaging catheters. The quantitative polarization metrics display notable
image contrast between several relevant coronary plaque microstructures that are difficult
to identify with conventional OCT and OFDI. Tissues rich in collagen and smooth
muscle cells exhibit birefringence, while lipid and macrophages cause depolarization.
In this review, we describe the basic principles of intravascular polarimetry, discuss the
interpretation of the polarization signatures, and outline promising avenues for future
research and clinical implications
A Lattice Monte Carlo Study of the Hot Electroweak Phase Transition
We study the finite temperature electroweak phase transition with lattice
perturbation theory and Monte Carlo techniques. Dimensional reduction is used
to approximate the full four-dimensional SU(2) + a fundamental doublet Higgs
theory by an effective three-dimensional SU(2) + adjoint Higgs + fundamental
Higgs theory with coefficients depending on temperature via screening masses
and mass counterterms. Fermions contribute to the effective theory only via the
and dependence of the coefficients. For sufficiently small
lattices ( for = 35 GeV) the study of the one-loop lattice
effective potential shows the existence of the {\em second} order phase
transition even for the small Higgs masses. At the same time, a clear signal of
a {\em first order} phase transition is seen on the lattice simulations with a
transition temperature close to but less than the value determined from the
perturbative calculations. This indicates that the dynamics of the first order
electroweak phase transition depends strongly on non-perturbative effects and
is not exclusively related to the so-called term in the effective
potential.Comment: 15 pages, use latex+epsfig, includes 6 ps-figures, CERN-TH.6901/9
Some aspects of heavy ion fusion-fission dynamics
Study of heavy ion induced fusion-fission reactions at near and below barrier energies has attracted a great deal of attention in recent years, due to the observations of anomalous features in the fragment angular distributions for many target-projectile systems. Additionally there are also measurements of the fragment spin distributions and time-scales of the fusion-fission reactions, which have provided important information on the dynamics of these processes. In the present paper, the emphasis would be to highlight some of the recent experimental findings and their implications on the dynamics of the fusion-fission reactions in heavy ion collisions at near and above barrier energies
Gauge Dependence of the High-Temperature 2-Loop Effective Potential for the Higgs Field
The high-temperature limit of the 2-loop effective potential for the Higgs
field is calculated from an effective 3d theory, in a general covariant gauge.
It is shown explicitly that a gauge-independent result can be extracted for the
equation of state from the gauge-dependent effective potential. The convergence
of perturbation theory is estimated in the broken phase, utilizing the gauge
dependence of the effective potential.Comment: 13 LaTeX-pages + 2 ps-figure (Instructions added to uudecode the
ps-file.
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