1,253 research outputs found
Fractional topological phase for entangled qudits
We investigate the topological structure of entangled qudits under unitary
local operations. Different sectors are identified in the evolution, and their
geometrical and topological aspects are analyzed. The geometric phase is
explicitly calculated in terms of the concurrence. As a main result, we predict
a fractional topological phase for cyclic evolutions in the multiply connected
space of maximally entangled states.Comment: REVTex, 4 page
SUPPORT Tools for evidence-informed health Policymaking (STP)
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Relationship between fish size and otolith length for 63 species of fishes from the Eastern North Pacific Ocean
Otoliths commonly are used to determine the taxon, age, and size of fishes. This information is useful for population management, predator-prey studies, and archaeological research. The relationship between the length of a fish and the length of its otoliths remains unknown for many species of marine fishes in the Pacific Ocean. Therefore, the relationships between fish length and fish weight, and between otolith length and fish length, were developed for 63 species of fishes caught in the eastern North Pacific Ocean. We also summarized similar relationships for 46 eastern North Pacific fish species reported in the literature. The relationship between fish length and otolith length was linear, and most of the variability was explained by a simple least-squares regression (r 2 > 0.700 for 45 of 63 species). The relationship between otolith length and fish length was not significantly different between left and right otoliths for all but one fish species. Images of otoliths from 77 taxa are included to assist in the identification of species. (PDF file contains 38 pages.
System and market failures: the unavailability of magnesium sulphate for the treatment of eclampsia and pre-eclampsia in Mozambique and Zimbabwe.
Low cost and effective drugs, such as magnesium sulphate, need to be included in initiatives to improve access to essential medicines in Afric
Large Dual Transformations and the Petrov-Diakonov Representation of the Wilson Loop
In this work, based on the Petrov-Diakonov representation of the Wilson loop
average W in the SU(2) Yang-Mills theory, together with the Cho-Fadeev-Niemi
decomposition, we present a natural framework to discuss possible ideas
underlying confinement and ensembles of defects in the continuum. In this
language we show how for different ensembles the surface appearing in the
Wess-Zumino term in W can be either decoupled or turned into a variable, to be
summed together with gauge fields, defects and dual fields. This is discussed
in terms of the regularity properties imposed by the ensembles on the dual
fields, thus precluding or enabling the possibility of performing the large
dual transformations that would be necessary to decouple the initial surface.Comment: 35 pages, LaTeX, corrected version, accepted for publication in Phys.
Rev.
Attractive Casimir effect in an infrared modified gluon bag model
In this work, we are motivated by previous attempts to derive the vacuum
contribution to the bag energy in terms of familiar Casimir energy calculations
for spherical geometries. A simple infrared modified model is introduced which
allows studying the effects of the analytic structure as well as the geometry
in a clear manner. In this context, we show that if a class of infrared
vanishing effective gluon propagators is considered, then the renormalized
vacuum energy for a spherical bag is attractive, as required by the bag model
to adjust hadron spectroscopy.Comment: 7 pages. 1 figure. Accepted for publication in Physical Review D.
Revised version with improved analysis and presentation, references adde
On the induced gauge invariant mass
We derive a general expression for the gauge invariant mass (m_G) for an
Abelian gauge field, as induced by vacuum polarization, in 1+1 dimensions. From
its relation to the chiral anomaly, we show that m_G has to satisfy a certain
quantization condition. This quantization can be, on the other hand, explicitly
verified by using the exact general expression for the gauge invariant mass in
terms of the fermion propagator. This result is applied to some explicit
examples, exploring the possibility of having interesting physical situations
where the value of departs from its canonical value. We also study the
possibility of generalizing the results to the 2+1 dimensional case at finite
temperature, showing that there are indeed situations where a finite and
non-vanishing gauge invariant mass is induced.Comment: 18 pages, Latex, 3 figures (pstex
SUPPORT Tools for evidence-informed health Policymaking (STP) 12: Finding and using research evidence about resource use and costs
This article is part of a series written for people responsible for making decisions about health policies and programmes and for those who support these decision makers
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