8,725 research outputs found
Leveraging higher salaries for nursing faculty
The nursing faculty pay scale at the University of Nevada, Las Vegas, has increased significantly over the past 5 years. This increase was driven by a number of factors: (a) the rapidly expanding population in Nevada, (b) the nursing shortage and the Nevada legislative mandate to double nursing enrollment in state schools, (c) the national nursing faculty shortage, and (d) the opening of private nursing schools in Nevada. This article describes how, given these factors, the faculty members were able to leverage a pay scale that is finally competitive with clinical appointments
Recursive Calculation of Effective Potential and Variational Resummation
We set up a method for a recursive calculation of the effective potential
which is applied to a cubic potential with imaginary coupling. The result is
resummed using variational perturbation theory (VPT), yielding an exponentially
fast convergence.Comment: Author Information under
http://www.physik.fu-berlin.de/~kleinert/institution.html Latest update of
paper (including all PS fonts) at
http://www.physik.fu-berlin.de/~kleinert/350
Quasiconformality and mass
We identify universal quasiconformal (walking) behaviour in non-Abelian gauge
field theories based on the mass-dependent all-order beta-function introduced
in arXiv:0908.1364. We find different types of walking behaviour in the
presence of (partially) massive species. We employ our findings to the
construction of candidate theories for dynamical electroweak symmetry breaking
by walking technicolour.Comment: 16 pages, 8 figures
Monitoring strip mining and reclamation with LANDSAT data in Belmont County, Ohio
The utility of LANDSAT digital data for mapping and monitoring surface mines in Belmont County, Ohio was investigated. Two data sets from 1976 and 1979 were processed to classify level 1 land covers and three strip mine categories in order to examine change over time and assess reclamation efforts. The two classifications were compared with aerial photographs. Results of the accuracy assessment show that both classifications are approximately 86 per cent correct, and that surface mine change detection (date-to-date comparison) is facilitated by the digital format of LANDSAT data
The distribution of microlensed light curve derivatives: the relationship between stellar proper motions and transverse velocity
We present a method for computing the probability distribution of microlensed
light curve derivatives both in the case of a static lens with a transverse
velocity, and in the case of microlensing that is produced through stellar
proper motions. The distributions are closely related in form, and can be
considered equivalent after appropriate scaling of the input transverse
velocity. The comparison of the distributions in this manner provides a
consistent way to consider the relative contribution to microlensing (both
large and small fluctuations) of the two classes of motion, a problem that is
otherwise an extremely expensive computational exercise. We find that the
relative contribution of stellar proper motions to the microlensing rate is
independent of the mass function assumed for the microlenses, but is a function
of optical depth and shear. We find that stellar proper motions produce a
higher overall microlensing rate than a transverse velocity of the same
magnitude. This effect becomes more pronounced at higher optical depth. With
the introduction of shear, the relative rates of microlensing become dependent
on the direction of the transverse velocity. This may have important
consequences in the case of quadruply lensed quasars such as Q2237+0305, where
the alignment of the shear vector with the source trajectory varies between
images.Comment: 12 pages, including 9 figures. Submitted to M.N.R.A.S. Revised
version includes a short section on the applicability of the metho
Exotic Statistics for Ordinary Particles in Quantum Gravity
Objects exhibiting statistics other than the familiar Bose and Fermi ones are
natural in theories with topologically nontrivial objects including geons,
strings, and black holes. It is argued here from several viewpoints that the
statistics of ordinary particles with which we are already familiar are likely
to be modified due to quantum gravity effects. In particular, such
modifications are argued to be present in loop quantum gravity and in any
theory which represents spacetime in a fundamentally piecewise-linear fashion.
The appearance of unusual statistics may be a generic feature (such as the
deformed position-momentum uncertainty relations and the appearance of a
fundamental length scale) which are to be expected in any theory of quantum
gravity, and which could be testable.Comment: Awarded an honourable mention in the 2008 Gravity Research Foundation
Essay Competitio
Disk/corona model: The transition to ADAF
We propose a model of the accretion flow onto a black hole consisting of the
accretion disk with an accreting two-temperature corona. The model is based on
assumptions about the radiative and conductive energy exchange between the two
phases and the pressure equilibrium. The complete model is determined by the
mass, the accretion rate, and the viscosity parameter. We present the radial
dependencies of parameters of such a two-phase flow, with advection in the
corona and the disk/corona mass exchange due to evaporation/condensation
included, and we determine the transition radius from a two-phase disk/corona
accretion to a single-phase optically thin flow (ADAF) in the innermost part of
the disk as a function of accretion rate. We identify the NLS1 galaxies with
objects accreting at a rate close to the Eddington accretion rate. The strong
variability of these objects may be related to the limit cycle behaviour
expected in this luminosity range, as the disk, unstable due to the dominance
by the radiation pressure, oscillates between the two stable branches: the
advection-dominated optically thick branch and the evaporation branch.Comment: Contributed talk presented at the Joint MPE,AIP,ESO workshop on
NLS1s, Bad Honnef, Dec. 1999, to appear in New Astronomy Reviews; also
available at http://wave.xray.mpe.mpg.de/conferences/nls1-worksho
Detection Rates for Close Binaries Via Microlensing
Microlensing is one of the most promising methods of reconstructing the
stellar mass function down to masses even below the hydrogen-burning limit. The
fundamental limit to this technique is the presence of unresolved binaries,
which can in principle significantly alter the inferred mass function. Here we
quantify the fraction of binaries that can be detected using microlensing,
considering specifically the mass ratio and separation of the binary. We find
that almost all binary systems with separations greater than of
their combined Einstein ring radius are detectable assuming a detection
threshold of . For two M dwarfs, this corresponds to a limiting separation
of \gsim 1 \au. Since very few observed M dwarfs have companions at
separations \lsim 1 \au, we conclude that close binaries will probably not
corrupt the measurements of the mass function. We find that the detectability
depends only weakly on the mass ratio. For those events for which individual
masses can be determined, we find that binaries can be detected down to .Comment: 19 pages including 6 figures. Uses phyyzx format. Send requests for
higher quality figures to [email protected]
Low-Energy Effective Action in Non-Perturbative Electrodynamics in Curved Spacetime
We study the heat kernel for the Laplace type partial differential operator
acting on smooth sections of a complex spin-tensor bundle over a generic
-dimensional Riemannian manifold. Assuming that the curvature of the U(1)
connection (that we call the electromagnetic field) is constant we compute the
first two coefficients of the non-perturbative asymptotic expansion of the heat
kernel which are of zero and the first order in Riemannian curvature and of
arbitrary order in the electromagnetic field. We apply these results to the
study of the effective action in non-perturbative electrodynamics in four
dimensions and derive a generalization of the Schwinger's result for the
creation of scalar and spinor particles in electromagnetic field induced by the
gravitational field. We discover a new infrared divergence in the imaginary
part of the effective action due to the gravitational corrections, which seems
to be a new physical effect.Comment: LaTeX, 42 page
A Characteristic Planetary Feature in Double-Peaked, High-Magnification Microlensing Events
A significant fraction of microlensing planets have been discovered in
high-magnification events, and a significant fraction of these events exhibit a
double-peak structure at their peak. However, very wide or very close binaries
can also produce double-peaked high-magnification events, with the same gross
properties as those produced by planets. Traditionally, distinguishing between
these two interpretations has relied upon detailed modeling, which is both
time-consuming and generally does not provide insight into the observable
properties that allow discrimination between these two classes of models. We
study the morphologies of these two classes of double-peaked high-magnification
events, and identify a simple diagnostic that can be used to immediately
distinguish between perturbations caused by planetary and binary companions,
without detailed modeling. This diagnostic is based on the difference in the
shape of the intra-peak region of the light curves. The shape is smooth and
concave for binary lensing, while it tends to be either boxy or convex for
planetary lensing. In planetary lensing this intra-peak morphology is due to
the small, weak cusp of the planetary central caustic located between the two
stronger cusps. We apply this diagnostic to five observed double-peaked
high-magnification events to infer their underlying nature. A corollary of our
study is that good coverage of the intra-peak region of double-peaked
high-magnification events is likely to be important for their unique
interpretation.Comment: 6 pages, 3 figure
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