17,136 research outputs found
A Peak Point Theorem for Uniform Algebras on Real-Analytic Varieties
It was once conjectured that if is a uniform algebra on its maximal ideal
space , and if each point of is a peak point for , then .
This peak-point conjecture was disproved by Brian Cole in 1968. Here we
establish a peak-point theorem for uniform algebras generated by real-analytic
functions on real-analytic varieties, generalizing previous results of the
authors and John Wermer
Gender Equity in Intercollegiate Athletics: Determinants of Title IX Compliance
Using new data on intercollegiate athletes, this article shows that recent improvement in Title IX compliance among NCAA Division I institutions was previously overestimated, and provides the first estimates of compliance in Divisions II and III. In addition, regression analyses investigate how institutional characteristics relate to the extent of non-compliance
Factor Price Disparity in the Feeder Cattle Market and Retained Ownership Decision Making: An Application of Farm-Level Feed-Out Data
This study uses farm-level data from a university feed-out program to evaluate how the value of feeder cattle ultimately realized through finishing and grid pricing differs from their market value at public auction. Results indicate that uncertainty related to feedlot performance, final carcass merits, and fed cattle prices likely contribute to significant risk premiums in the feeder cattle market. This is consistent with the theory of factor price disparity. This result indicates that producers of cattle with known feedlot performance and/or carcass potential may be better off retaining ownership of their calves or marketing them in a way that communicates the information that is known about their potential performance directly to the buyer.Marketing,
How credible are capital spending surveys as forecasts?
A comparison of the reliability of the Commerce Department's capital spending survey with that of several alternative forecasts.Capital investments ; Forecasting
The divergence characteristics of constrained-sheath optics systems for use with 5-eV atomic oxygen sources
The potential usefulness of the constrained sheath optics concept as a means of controlling the divergence of low energy, high current density ion beams is examined numerically and experimentally. Numerical results demonstrate that some control of the divergence of typical ion beamlets can be achieved at perveance levels of interest by contouring the surface of the constrained sheath properly. Experimental results demonstrate that a sheath can be constrained by a wire mesh attached to the screen plate of the ion optics system. The numerically predicted beamlet divergence characteristics are shown to depart from those measured experimentally, and additional numerical analysis is used to demonstrate that this departure is probably due to distortions of the sheath caused by the fact that it attempts to conform to the individual wires that make up the sheath constraining mesh. The concept is considered potentially useful in controlling the divergence of ion beamlets in applications where low divergence, low energy, high current density beamlets are being sought, but more work is required to demonstrate this for net beam ion energies as low as 5 eV
Modular vector fields attached to Dwork family: Lie algebra
We introduce an algebraic group that acts from right on the moduli
space of Calabi-Yau -folds arising from Dwork family enhanced
with differential forms, and describe its Lie algebra . We
observe that together with a modular vector field on generates another Lie algebra , called
AMSY-Lie algebra, such that . We find
as a Lie subalgebra of that
contains .Comment: 20 page
A Mission to Test the Pioneer Anomaly
Analysis of the radio tracking data from the Pioneer 10/11 spacecraft has
consistently indicated the presence of an anomalous small Doppler frequency
drift. The drift can be interpreted as being due to a constant acceleration of
a_P= (8.74 +/- 1.33) x 10^{-8} cm/s^2 directed towards the Sun. Although it is
suspected that there is a systematic origin to the effect, none has been found.
The nature of this anomaly has become of growing interest in the fields of
relativistic cosmology, astro- and gravitational physics as well as in the
areas of spacecraft design and high-precision navigation. We present a concept
for a designated deep-space mission to test the discovered anomaly. A number of
critical requirements and design considerations for such a mission are outlined
and addressed.Comment: Final changes for publication. Honorable Mention, 2002 Gravity
Research Foundation Essay
Chameleon effect and the Pioneer anomaly
The possibility that the apparent anomalous acceleration of the Pioneer 10
and 11 spacecraft may be due, at least in part, to a chameleon field effect is
examined. A small spacecraft, with no thin shell, can have a more pronounced
anomalous acceleration than a large compact body, such as a planet, having a
thin shell. The chameleon effect seems to present a natural way to explain the
differences seen in deviations from pure Newtonian gravity for a spacecraft and
for a planet, and appears to be compatible with the basic features of the
Pioneer anomaly, including the appearance of a jerk term. However, estimates of
the size of the chameleon effect indicate that its contribution to the
anomalous acceleration is negligible. We conclude that any inverse-square
component in the anomalous acceleration is more likely caused by an unmodelled
reaction force from solar-radiation pressure, rather than a chameleon field
effect.Comment: 16 pages; to appear in Phys.Rev.
- …