2,581 research outputs found
Weâre All Human, but Some Are More Human Than Others: Thoughts on the Hypocrisies of Global Travel
A Note on the Equality of Algebraic and Geometric D-Brane Charges in WZW Models
The algebraic definition of charges for symmetry-preserving D-branes in
Wess-Zumino-Witten models is shown to coincide with the geometric definition,
for all simple Lie groups. The charge group for such branes is computed from
the ambiguities inherent in the geometric definition.Comment: 12 pages, fixed typos, added references and a couple of remark
A Comparison of the Operating Characteristics of Two Cooling Water Systems using Chlorine and Chlorine Dioxide Biocides
Tests using side streams from an industrial cooling water system have been made to compare the corrosion rates associated with the use of chlorine and chlorine dioxide biocides. Two streams were employed, a once through and a recirculating system employing a cooling tower. The water used in the plant originated from a canal. The results of the tests revealed differences in characteristics between the circuits, depending on the biocide used and the operating conditions. The data obtained demonstrated a higher corrosion rate of 1.5 mpy with chlorine compared to 1.0 mpy using chlorine dioxide
Equivariant Symplectic Geometry of Gauge Fixing in Yang-Mills Theory
The Faddeev-Popov gauge fixing in Yang-Mills theory is interpreted as
equivariant localization. It is shown that the Faddeev-Popov procedure amounts
to a construction of a symplectic manifold with a Hamiltonian group action. The
BRST cohomology is shown to be equivalent to the equivariant cohomology based
on this symplectic manifold with Hamiltonian group action. The ghost operator
is interpreted as a (pre)symplectic form and the gauge condition as the moment
map corresponding to the Hamiltonian group action. This results in the
identification of the gauge fixing action as a closed equivariant form, the sum
of an equivariant symplectic form and a certain closed equivariant 4-form which
ensures convergence. An almost complex structure compatible with the symplectic
form is constructed. The equivariant localization principle is used to localize
the path integrals onto the gauge slice. The Gribov problem is also discussed
in the context of equivariant localization principle. As a simple illustration
of the methods developed in the paper, the partition function of N=2
supersymmetric quantum mechanics is calculated by equivariant localizationComment: 46 pages, added remarks, typos and references correcte
Physical States at the Tachyonic Vacuum of Open String Field Theory
We illustrate a method for computing the number of physical states of open
string theory at the stable tachyonic vacuum in level truncation approximation.
The method is based on the analysis of the gauge-fixed open string field theory
quadratic action that includes Fadeev-Popov ghost string fields. Computations
up to level 9 in the scalar sector are consistent with Sen's conjecture about
the absence of physical open string states at the tachyonic vacuum. We also
derive a long exact cohomology sequence that relates relative and absolute
cohomologies of the BRS operator at the non-perturbative vacuum. We use this
exact result in conjunction with our numerical findings to conclude that the
higher ghost number non-perturbative BRS cohomologies are non-empty.Comment: 43 pages, 16 eps figures, LaTe
Complex Line Bundles over Simplicial Complexes and their Applications
Discrete vector bundles are important in Physics and recently found
remarkable applications in Computer Graphics. This article approaches discrete
bundles from the viewpoint of Discrete Differential Geometry, including a
complete classification of discrete vector bundles over finite simplicial
complexes. In particular, we obtain a discrete analogue of a theorem of Andr\'e
Weil on the classification of hermitian line bundles. Moreover, we associate to
each discrete hermitian line bundle with curvature a unique piecewise-smooth
hermitian line bundle of piecewise constant curvature. This is then used to
define a discrete Dirichlet energy which generalizes the well-known cotangent
Laplace operator to discrete hermitian line bundles over Euclidean simplicial
manifolds of arbitrary dimension
Proton imaging of stochastic magnetic fields
Recent laser-plasma experiments report the existence of dynamically
significant magnetic fields, whose statistical characterisation is essential
for understanding the physical processes these experiments are attempting to
investigate. In this paper, we show how a proton imaging diagnostic can be used
to determine a range of relevant magnetic field statistics, including the
magnetic-energy spectrum. To achieve this goal, we explore the properties of an
analytic relation between a stochastic magnetic field and the image-flux
distribution created upon imaging that field. We conclude that features of the
beam's final image-flux distribution often display a universal character
determined by a single, field-scale dependent parameter - the contrast
parameter - which quantifies the relative size of the correlation length of the
stochastic field, proton displacements due to magnetic deflections, and the
image magnification. For stochastic magnetic fields, we establish the existence
of four contrast regimes - linear, nonlinear injective, caustic and diffusive -
under which proton-flux images relate to their parent fields in a qualitatively
distinct manner. As a consequence, it is demonstrated that in the linear or
nonlinear injective regimes, the path-integrated magnetic field experienced by
the beam can be extracted uniquely, as can the magnetic-energy spectrum under a
further statistical assumption of isotropy. This is no longer the case in the
caustic or diffusive regimes. We also discuss complications to the
contrast-regime characterisation arising for inhomogeneous, multi-scale
stochastic fields, as well as limitations currently placed by experimental
capabilities on extracting magnetic field statistics. The results presented in
this paper provide a comprehensive description of proton images of stochastic
magnetic fields, with applications for improved analysis of given proton-flux
images.Comment: Main paper pp. 1-29; appendices pp. 30-84. 24 figures, 2 table
The Standard Model Fermion Spectrum From Complex Projective spaces
It is shown that the quarks and leptons of the standard model, including a
right-handed neutrino, can be obtained by gauging the holonomy groups of
complex projective spaces of complex dimensions two and three. The spectrum
emerges as chiral zero modes of the Dirac operator coupled to gauge fields and
the demonstration involves an index theorem analysis on a general complex
projective space in the presence of topologically non-trivial SU(n)xU(1) gauge
fields. The construction may have applications in type IIA string theory and
non-commutative geometry.Comment: 13 pages. Typset using LaTeX and JHEP3 style files. Minor typos
correcte
"It's Huge, in a Way." Conflicting Stakeholder Priorities for Managing Hearing Impairment for People Living with Dementia in Residential Aged Care Facilities
Objectives:
The aims of this study were to a) explore the impact of hearing impairment on people living with dementia in residential aged care facilities (RACFs) and b) investigate management of hearing impairment for this population. /
Methods:
A descriptive qualitative approach, consisting of semi-structured interviews, was conducted with 23 participants across four stakeholder groups (audiologists, care staff, family members and individuals with dementia and hearing impairment living in RACFs). /
Results:
Thematic analysis revealed an overarching theme of âdifferent priorities for managing hearing impairmentâ that emerged from the data. Audiologists and care staff prioritized different practices for managing hearing impairment: audiologists emphasized hearing aids and care staff emphasized communication strategies. Care staff also identified that current management of hearing impairment was sub-optimal as they do not prioritize managing it. /
Conclusions:
Residents with dementia and hearing impairment living in RACFs are not receiving optimal hearing management. Further research is required to understand the factors that influence this
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