26,352 research outputs found
Agency Behavior in a Nonprofit Setting: Effects of the 1984 Supreme Court NCAA Decision
The NCAA is commonly viewed as a cartel. We model the cartel relationship between the member teams and the NCAA central organization as a principal-agent relationship. Our model predicts imperfect agency behavior on the part of the NCAA with corresponding overregulation relative to the level preferred by the member teams. We empirically test the model by examining the impact of the 1984 Supreme Court decision that reassigned the telecast rights for intercollegiate football from the NCAA to the individual member teams. Our empirical estimates of telecasts, attendance, and competitive balance support the prediction of imperfect agency behavior by the NCAA.NCAA, Intercollegiate Football, Broadcast Regulation, Antitrust Policy
Extremal black holes, gravitational entropy and nonstationary metric fields
We show that extremal black holes have zero entropy by pointing out a simple
fact: they are time-independent throughout the spacetime and correspond to a
single classical microstate. We show that non-extremal black holes, including
the Schwarzschild black hole, contain a region hidden behind the event horizon
where all their Killing vectors are spacelike. This region is nonstationary and
the time labels a continuous set of classical microstates, the phase space
, where is a three-metric induced on a
spacelike hypersurface and is its momentum conjugate. We
determine explicitly the phase space in the interior region of the
Schwarzschild black hole. We identify its entropy as a measure of an outside
observer's ignorance of the classical microstates in the interior since the
parameter which labels the states lies anywhere between 0 and 2M. We
provide numerical evidence from recent simulations of gravitational collapse in
isotropic coordinates that the entropy of the Schwarzschild black hole stems
from the region inside and near the event horizon where the metric fields are
nonstationary; the rest of the spacetime, which is static, makes no
contribution. Extremal black holes have an event horizon but in contrast to
non-extremal black holes, their extended spacetimes do not possess a bifurcate
Killing horizon. This is consistent with the fact that extremal black holes are
time-independent and therefore have no distinct time-reverse.Comment: 12 pages, 2 figures. To appear in Class. and Quant. Gravity. Based on
an essay selected for honorable mention in the 2010 gravity research
foundation essay competitio
Accumulator for shaft encoder
Digital accumulator relies almost entirely on integrated circuitry to process the data derived from the outputs of gyro shaft encoder. After the read command is given, the output register collects and stores the data that are on the set output terminals of the up-down counters
Study of the impact of cruise speed on scheduling and productivity of commercial transport aircraft
A comparison is made between airplane productivity and utilization levels derived from commercial airline type schedules which were developed for two subsonic and four supersonic cruise speed aircraft. The cruise speed component is the only difference between the schedules which are based on 1995 passenger demand forecasts. Productivity-to-speed relationships were determined for the three discrete route systems: North Atlantic, Trans-Pacific, and North-South America. Selected combinations of these route systems were also studied. Other areas affecting the productivity-to-speed relationship such as aircraft design range and scheduled turn time were examined
Rippled Cosmological Dark Matter from Damped Oscillating Newton Constant
Let the reciprocal Newton 'constant' be an apparently non-dynamical
Brans-Dicke scalar field damped oscillating towards its General Relativistic
VEV. We show, without introducing additional matter fields or dust, that the
corresponding cosmological evolution averagely resembles, in the Jordan frame,
the familiar dark radiation -> dark matter -> dark energy domination sequence.
The fingerprints of our theory are fine ripples, hopefully testable, in the FRW
scale factor; they die away at the General Relativity limit. The possibility
that the Brans-Dicke scalar also serves as the inflaton is favorably examined.Comment: RevTex4, 12 pages, 5 figures; Minor revision, References adde
Ground-based measurements of O3, NO2, OClO, and BrO during the 1987 Antarctic ozone depletion event
Near-ultraviolet absorption spectroscopy in the wavelength range from 330 to 370 nm was used to measure O3, NO2, OClO, and BrO at McMurdo Station (78S) during 1987. Visible absorption measurements of O3, NO2, and OClO were also obtained using the wavelength range from about 403 to 453 nm. These data are described and compared to observations obtained in 1986. It is shown that comparisons of observations in the two wavelength ranges provide a sensitive measure of the altitude where the bulk of atmospheric absorption takes place
Two Component Model of Dark Energy
We consider the possibility that the dark energy is made up of two or more
independent components, each having a different equation of state. We fit the
model with supernova and gamma-ray burst (GRB) data from resent observations,
and use the Markov Chain Monte Carlo (MCMC) technique to estimate the allowed
parameter regions. We also use various model selection criteria to compare the
two component model with the LCDM, one component dark energy model with static
or variable w(XCDM), and with other multi-component models. We find that the
two component models can give reasonably good fit to the current data. For some
data sets, and depending somewhat on the model selection criteria, the two
component model can give better fit to the data than XCDM with static w and
XCDM with variable w parameterized by w = w_0 + w_az/(1+z).Comment: 10 pages, 8 figures, 3 tables; Version accepted by PR
The Red Queen visits Minkowski Space
When Alice went `Through the Looking Glass' [1], she found herself in a
situation where she had to run as fast as she could in order to stay still. In
accordance with the dictum that truth is stranger than fiction, we will see
that it is possible to find a situation in special relativity where running
towards one's target is actually counter-productive. Although the situation is
easily analysed algebraically, the qualitative properties of the analysis are
greatly illuminated by the use of space-time diagrams
On the Miura map between the dispersionless KP and dispersionless modified KP hierarchies
We investigate the Miura map between the dispersionless KP and dispersionless
modified KP hierarchies. We show that the Miura map is canonical with respect
to their bi-Hamiltonian structures. Moreover, inspired by the works of Takasaki
and Takebe, the twistor construction of solution structure for the
dispersionless modified KP hierarchy is given.Comment: 19 pages, Latex, no figure
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