3,351 research outputs found
The Future of Private Loans: Who is Borrowing, and Why?
Examines developments in private loans within the student lending industry, characteristics of loan borrowers, and trends that might impact the growth of private loans in the future
Relaxation of atomic polarization in paraffin-coated cesium vapor cells
The relaxation of atomic polarization in buffer-gas-free, paraffin-coated
cesium vapor cells is studied using a variation on Franzen's technique of
``relaxation in the dark'' [Franzen, Phys. Rev. {\bf 115}, 850 (1959)]. In the
present experiment, narrow-band, circularly polarized pump light, resonant with
the Cs D2 transition, orients atoms along a longitudinal magnetic field, and
time-dependent optical rotation of linearly polarized probe light is measured
to determine the relaxation rates of the atomic orientation of a particular
hyperfine level. The change in relaxation rates during light-induced atomic
desorption (LIAD) is studied. No significant change in the spin relaxation rate
during LIAD is found beyond that expected from the faster rate of spin-exchange
collisions due to the increase in Cs density.Comment: 14 pages, 14 figure
Quantum and Classical Dissipative Effects on Tunnelling in Quantum Hall Bilayers
We discuss the interplay between transport and dissipation in quantum Hall
bilayers. We show that quantum effects are relevant in the pseudospin picture
of these systems, leading either to direct tunnelling currents or to quantum
dissipative processes that damp oscillations around the ground state. These
quantum effects have their origins in resonances of the classical spin system.Comment: 12 pages. Minor changes from v
Preconditioning Maximal Center Gauge with Stout Link Smearing in SU(3)
Center vortices are studied in SU(3) gauge theory using Maximal Center Gauge
(MCG) fixing. Stout link smearing and over-improved stout link smearing are
used to construct a preconditioning gauge field transformation, applied to the
original gauge field before fixing to MCG. We find that preconditioning
successfully achieves higher gauge fixing maxima. We observe a reduction in the
number of identified vortices when preconditioning is used, and also a
reduction in the vortex-only string tension.Comment: 9 pages, 4 figure
Conglomerate Multi-Fidelity Gaussian Process Modeling, with Application to Heavy-Ion Collisions
In an era where scientific experimentation is often costly, multi-fidelity
emulation provides a powerful tool for predictive scientific computing. While
there has been notable work on multi-fidelity modeling, existing models do not
incorporate an important ``conglomerate'' property of multi-fidelity
simulators, where the accuracies of different simulator components (modeling
separate physics) are controlled by different fidelity parameters. Such
conglomerate simulators are widely encountered in complex nuclear physics and
astrophysics applications. We thus propose a new CONglomerate multi-FIdelity
Gaussian process (CONFIG) model, which embeds this conglomerate structure
within a novel non-stationary covariance function. We show that the proposed
CONFIG model can capture prior knowledge on the numerical convergence of
conglomerate simulators, which allows for cost-efficient emulation of
multi-fidelity systems. We demonstrate the improved predictive performance of
CONFIG over state-of-the-art models in a suite of numerical experiments and two
applications, the first for emulation of cantilever beam deflection and the
second for emulating the evolution of the quark-gluon plasma, which was
theorized to have filled the Universe shortly after the Big Bang
Degenerate Bose liquid in a fluctuating gauge field
We study the effect of a strongly fluctuating gauge field on a degenerate
Bose liquid, relevant to the charge degrees of freedom in doped Mott
insulators. We find that the superfluidity is destroyed. The resulting metallic
phase is studied using quantum Monte Carlo methods. Gauge fluctuations cause
the boson world lines to retrace themselves. We examine how this world-line
geometry affects the physical properties of the system. In particular, we find
a transport relaxation rate of the order of 2kT, consistent with the normal
state of the cuprate superconductors. We also find that the density excitations
of this model resemble that of the full tJ model.Comment: 4 pages. Uses RevTeX, epsf, multicols macros. 5 postscript figure
Examining associations Between School-Level Determinants and the Implementation of Physical activity Opportunities
School-based physical activity (PA) opportunities can help students engage in greater amounts of daily PA, meet PA guidelines, and lead to improved health and educational outcomes. However, we do not completely understand the organizational challenges to implementing these opportunities successfully. This exploratory study examined associations between school-level determinants and the implementation of school-based PA opportunities. We analyzed cross-sectional survey data from schools (n = 46) participating in the Healthy Zone School Program (HZSP) (Dallas, Texas, USA) during 2019-2020. Respondents completed an electronic survey that included measures of school-level determinants (e.g. culture, leadership, priority) and the implementation of school-based PA opportunities. We used linear regression models to examine associations between determinants and implementation outcomes (number of PA opportunities delivered, perceived overall success of each PA program/activity used). After adjusting for campus type (i.e. elementary, middle, high, K-12), student race/ethnicity, and percentage of economically disadvantaged students, no constructs were associated with the number of PA opportunities implemented. Linear regression models suggest access to knowledge and information (β = 0.39, P = .012, 95% CI = 0.24-1.44) and implementation climate (β = 0.34, P = .045, 95% CI = 0.02-1.59) were positively associated with the success of school-based PA opportunities. Our findings provide suggestive evidence that access to knowledge and information and a supportive school climate may improve the overall success of PA opportunities provided to students. Future research should examine additional school-level determinants to understand their importance to implementation and inform the development of strategies to improve schools\u27 capacity for implementing PA opportunities successfully
- …