2,261 research outputs found
Generation of Hidden Optical-Polarization: Squeezing and Non-Classicality
A monochromatic double-mode coherent light endowed with orthogonally
polarized photons propagating collinearly is studied in Degenerate Parametric
Amplification. Generation of Hidden Optical- Polarized States is shown by
non-zero values of Index of Hidden Optical-Polarization. Squeezing in HOPS is
demonstrated by recognizing a Squeezing function. The Non-Classical feature of
HOPS is observed by 'degree of Hidden Optical-Polarization' which attains
non-classical value 'greater than unity'. The dynamical nature of Generation,
Squeezing and Non-Classicality are numerically presented.Comment: 14 pages and 02 figure
Quality of a Which-Way Detector
We introduce a measure Q of the "quality" of a quantum which-way detector,
which characterizes its intrinsic ability to extract which-way information in
an asymmetric two-way interferometer. The "quality" Q allows one to separate
the contribution to the distinguishability of the ways arising from the quantum
properties of the detector from the contribution stemming from a-priori
which-way knowledge available to the experimenter, which can be quantified by a
predictability parameter P. We provide an inequality relating these two sources
of which-way information to the value of the fringe visibility displayed by the
interferometer. We show that this inequality is an expression of duality,
allowing one to trace the loss of coherence to the two reservoirs of which-way
information represented by Q and P. Finally, we illustrate the formalism with
the use of a quantum logic gate: the Symmetric Quanton-Detecton System (SQDS).
The SQDS can be regarded as two qubits trying to acquire which way information
about each other. The SQDS will provide an illustrating example of the
reciprocal effects induced by duality between system and which-way detector.Comment: 10 pages, 5 figure
Theoretical Uncertainties in Red Giant Branch Evolution: The Red Giant Branch Bump
A Monte Carlo simulation exploring uncertainties in standard stellar
evolution theory on the red giant branch of metal-poor globular clusters has
been conducted. Confidence limits are derived on the absolute V-band magnitude
of the bump in the red giant branch luminosity function (M_v,b) and the excess
number of stars in thebump, R_b. The analysis takes into account uncertainties
in the primordial helium abundance, abundance of alpha-capture elements,
radiative and conductive opacities, nuclear reaction rates, neutrino energy
losses, the treatments of diffusion and convection, the surface boundary
conditions, and color transformations.
The uncertainty in theoretical values for the red giant bump magnitude varies
with metallicity between +0.13/-0.12 mag at [Fe/H] = -2.4 and +0.23/-0.21 mag
at [Fe/H] = -1.0 to 0.50 at [Fe/H] =
-1.0. These theoretical values for R_b are in agreement with observations.Comment: 30 pages, 6 figures. To appear in Ap
AN INDIVIDUALIZED MARKING SCHEME FOR SANDHILL CRANES AND ITS USE TO DETERMINE FALL MIGRATION INTERVAL
A color-band based marking scheme was used for individually marking sa ndhill cranes in Florida. The band-loss rate was 2.8% per year between 1977 and 1988. Band loss was greatest on bands placed below the ankle joint and occurred most frequently during years 2 to 5. Color-marked individuals monitored during fall migration averaged 6.2 days (r=5-13 days) between the Jasper-Pulaski Fish and Wildlife area in northwestern Indiana and winlering areas in northern Florida
Implied Filtering Densities on Volatility's Hidden State
We formulate and analyze an inverse problem using derivatives prices to
obtain an implied filtering density on volatility's hidden state. Stochastic
volatility is the unobserved state in a hidden Markov model (HMM) and can be
tracked using Bayesian filtering. However, derivative data can be considered as
conditional expectations that are already observed in the market, and which can
be used as input to an inverse problem whose solution is an implied conditional
density on volatility. Our analysis relies on a specification of the martingale
change of measure, which we refer to as \textit{separability}. This
specification has a multiplicative component that behaves like a risk premium
on volatility uncertainty in the market. When applied to SPX options data, the
estimated model and implied densities produce variance-swap rates that are
consistent with the VIX volatility index. The implied densities are relatively
stable over time and pick up some of the monthly effects that occur due to the
options' expiration, indicating that the volatility-uncertainty premium could
experience cyclic effects due to the maturity date of the options
Trinity University\u27s Summer Bridge Program: Navigating the Changing Demographics in Higher Education
Our article is divided into five sections. First, our study explores the demographic, economic, and cultural changes influencing higher education. We also explain the tangible and intangible benefits of a college education for first-generation, underrepresented students (FGUS). Second, we provide a brief discussion of the history of Trinity University and our Summer Bridge program. Third, our study describes our Summer Bridge program. Fourth, the data we collected examines how our Summer Bridge students’ grades and retention rates compare to our other first-year students. And, fifth, our article concludes with a discussion of future directions for our Summer Bridge program and how it may apply to other higher educational institutions. In particular, we offer recommendations for other student affairs professionals who also will be experiencing an increase in first-generation, underrepresented students
Inventories and the Stockout Constraint in General Equilibrium
We study the implications of a stockout constraint in a dynamic general equilibrium model, which can explain both standard business cycle and inventory facts. Under this constraint, inventories and demand are complements in generating sales, and hence the optimal level of inventories increases in expected demand. We show that the inventory to sales ratio is both persistent and countercyclical because the cost of carrying inventories is mainly determined by the interest rate. We use this model to disentangle output and sales, by matching the key inventory moments, and find that preference and productivity shocks are equally important in the data. Finally, we assess whether improvements in inventory management can explain the Great Moderation. We find that, although improvements in inventory management can reduce the need for inventory holdings, which decreases output volatility relative to sales volatility, lower levels of inventories actually increases sales volatility. Because these two effects offset each other, a change in inventory management does not change output volatility to any great extent
Cognitive Effort Avoidance in Veterans with Suicide Attempt Histories
Suicide attempts (SA) are increasing in the United States, especially in veterans. Discovering individual cognitive features of the subset of suicide ideators who attempt suicide is critical. Cognitive theories attribute SA to facile schema-based negative interpretations of environmental events. Over-general autobiographical memory and facile solutions in problem solving tasks in SA survivors suggest that aversion to expending cognitive effort may be a neurobehavioral marker of SA risk. In veterans receiving care for mood disorder, we compared cognitive effort discounting and evidence-gathering in a beads task between veterans with (SAHx+; n = 26) versus without (SAHx-; n = 22) a history of SA. Groups did not differ in depressed mood or in a proxy metric of premorbid intelligence. Compared to SAHx- participants, SAHx+ participants self-reported significantly more severe cognitive problems in most domains, and also eschewed choice to earn higher monetary reward if earning it required a slightly increased working memory (WM) demand relative to an easy WM task. There was no group difference, however, in extent of evidence-gathering before declaring a conclusion in a beads task. These preliminary data suggest that aversion to expenditure of cognitive effort, potentially as a component of cognitive difficulties, may be a marker for SA risk
The ACS LCID project IV: detection of the RGB bump in isolated galaxies of the Local Group
We report the detection and analysis of the red giant branch luminosity
function bump in a sample of isolated dwarf galaxies in the Local Group. We
have designed a new analysis approach comparing the observed color-magnitude
diagrams with theoretical best-fit color-magnitude diagrams derived from
precise estimates of the star formation histories of each galaxy. This analysis
is based on studying the difference between the V-magnitude of the RGB bump and
the horizontal branch at the level of the RR Lyrae instability strip
(Delta_vhbb) and we discuss here a technique for reliably measuring this
quantity in complex stellar systems. By using this approach, we find that the
difference between the observed and predicted values of Delta_vhbb is +0.13 +/-
0.14 mag. This is smaller, by about a factor of two, than the well-known
discrepancy between theory and observation at low metallicity commonly derived
for Galactic globular clusters. This result is confirmed by a comparison
between the adopted theoretical framework and empirical estimates of the
Delta_vhbb parameter for both a large database of Galactic globular clusters
and for four other dSph galaxies for which this estimate is available in the
literature. We also investigate the strength of the red giant branch bump
feature (R_bump), and find very good agreement between the observed and
theoretically predicted R_bump values. This agreement supports the reliability
of the evolutionary lifetimes predicted by theoretical models of the evolution
of low-mass stars.Comment: Accepted for publication on Ap
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