250 research outputs found
Demonstration of superluminal effects in an absorptionless, non-reflective system
We present an experimental and theoretical study of a simple, passive system
consisting of a birefringent, two-dimensional photonic crystal and a polarizer
in series, and show that superluminal dispersive effects can arise even though
no incident radiation is absorbed or reflected. We demonstrate that a vector
formulation of the Kramers-Kronig dispersion relations facilitates an
understanding of these counter-intuitive effects.Comment: 6 pages, 3 figures, accepted on Physical Review Letter
Athletic Ticket Pricing in the Collegiate Environment: An Agenda for Research
s pressure mounts for intercollegiate athletic departments to be more selfsufficient, administrators must respond by increasing generated revenues. Despite the importance of ticket sales in this endeavor, however, little is known about the underlying ticket pricing structures and policies used by National Collegiate Athletic Association (NCAA) institutions. Of the limited existing scholarship focused on managerial pricing decisions in the field of sport management, only professional sports settings have been addressed. Given the unique operational differences between professional and intercollegiate sport, this paper is designed to establish a foundation from which to build future research concerning the pricing of college sport tickets. The frameworks of stakeholder theory and institutional theory are proposed to ground future study in an attempt to strengthen our understanding of the process and behavior of price setting in intercollegiate athletics
Athletic Ticket Pricing in the Collegiate Environment: An Agenda for Research
As pressure mounts for intercollegiate athletic departments to be more selfsufficient, administrators must respond by increasing generated revenues. Despite the importance of ticket sales in this endeavor, however, little is known about the underlying ticket pricing structures and policies used by National Collegiate Athletic Association (NCAA) institutions. Of the limited existing scholarship focused on managerial pricing decisions in the field of sport management, only professional sports settings have been addressed. Given the unique operational differences between professional and intercollegiate sport, this paper is designed to establish a foundation from which to build future research concerning the pricing of college sport tickets. The frameworks of stakeholder theory and institutional theory are proposed to ground future study in an attempt to strengthen our understanding of the process and behavior of price setting in intercollegiate athletics
The distribution of transit durations for Kepler planet candidates and implications for their orbital eccentricities
‘In these times, during the rise in the popularity of institutional repositories, the Society does not forbid authors from depositing their work in such repositories. However, the AAS regards the deposit of scholarly work in such repositories to be a decision of the individual scholar, as long as the individual's actions respect the diligence of the journals and their reviewers.’ Original article can be found at : http://iopscience.iop.org/ Copyright American Astronomical SocietyDoppler planet searches have discovered that giant planets follow orbits with a wide range of orbital eccentricities, revolutionizing theories of planet formation. The discovery of hundreds of exoplanet candidates by NASA's Kepler mission enables astronomers to characterize the eccentricity distribution of small exoplanets. Measuring the eccentricity of individual planets is only practical in favorable cases that are amenable to complementary techniques (e.g., radial velocities, transit timing variations, occultation photometry). Yet even in the absence of individual eccentricities, it is possible to study the distribution of eccentricities based on the distribution of transit durations (relative to the maximum transit duration for a circular orbit). We analyze the transit duration distribution of Kepler planet candidates. We find that for host stars with T > 5100 K we cannot invert this to infer the eccentricity distribution at this time due to uncertainties and possible systematics in the host star densities. With this limitation in mind, we compare the observed transit duration distribution with models to rule out extreme distributions. If we assume a Rayleigh eccentricity distribution for Kepler planet candidates, then we find best fits with a mean eccentricity of 0.1-0.25 for host stars with T ≤ 5100 K. We compare the transit duration distribution for different subsets of Kepler planet candidates and discuss tentative trends with planetary radius and multiplicity. High-precision spectroscopic follow-up observations for a large sample of host stars will be required to confirm which trends are real and which are the results of systematic errors in stellar radii. Finally, we identify planet candidates that must be eccentric or have a significantly underestimated stellar radius.Peer reviewedFinal Accepted Versio
Planetary Candidates Observed by Kepler IV: Planet Sample From Q1-Q8 (22 Months)
We provide updates to the Kepler planet candidate sample based upon nearly
two years of high-precision photometry (i.e., Q1-Q8). From an initial list of
nearly 13,400 Threshold Crossing Events (TCEs), 480 new host stars are
identified from their flux time series as consistent with hosting transiting
planets. Potential transit signals are subjected to further analysis using the
pixel-level data, which allows background eclipsing binaries to be identified
through small image position shifts during transit. We also re-evaluate Kepler
Objects of Interest (KOI) 1-1609, which were identified early in the mission,
using substantially more data to test for background false positives and to
find additional multiple systems. Combining the new and previous KOI samples,
we provide updated parameters for 2,738 Kepler planet candidates distributed
across 2,017 host stars. From the combined Kepler planet candidates, 472 are
new from the Q1-Q8 data examined in this study. The new Kepler planet
candidates represent ~40% of the sample with Rp~1 Rearth and represent ~40% of
the low equilibrium temperature (Teq<300 K) sample. We review the known biases
in the current sample of Kepler planet candidates relevant to evaluating planet
population statistics with the current Kepler planet candidate sample.Comment: 12 pages, 8 figures, Accepted ApJ Supplemen
Transit Timing Observations from Kepler: VII. Confirmation of 27 planets in 13 multiplanet systems via Transit Timing Variations and orbital stability
We confirm 27 planets in 13 planetary systems by showing the existence of
statistically significant anti-correlated transit timing variations (TTVs),
which demonstrates that the planet candidates are in the same system, and
long-term dynamical stability, which places limits on the masses of the
candidates---showing that they are planetary. %This overall method of planet
confirmation was first applied to \kepler systems 23 through 32. All of these
newly confirmed planetary systems have orbital periods that place them near
first-order mean motion resonances (MMRs), including 6 systems near the 2:1
MMR, 5 near 3:2, and one each near 4:3, 5:4, and 6:5. In addition, several
unconfirmed planet candidates exist in some systems (that cannot be confirmed
with this method at this time). A few of these candidates would also be near
first order MMRs with either the confirmed planets or with other candidates.
One system of particular interest, Kepler-56 (KOI-1241), is a pair of planets
orbiting a 12th magnitude, giant star with radius over three times that of the
Sun and effective temperature of 4900 K---among the largest stars known to host
a transiting exoplanetary system.Comment: 12 pages, 13 figures, 5 tables. Submitted to MNRA
From Heisenberg matrix mechanics to EBK quantization: theory and first applications
Despite the seminal connection between classical multiply-periodic motion and
Heisenberg matrix mechanics and the massive amount of work done on the
associated problem of semiclassical (EBK) quantization of bound states, we show
that there are, nevertheless, a number of previously unexploited aspects of
this relationship that bear on the quantum-classical correspondence. In
particular, we emphasize a quantum variational principle that implies the
classical variational principle for invariant tori. We also expose the more
indirect connection between commutation relations and quantization of action
variables. With the help of several standard models with one or two degrees of
freedom, we then illustrate how the methods of Heisenberg matrix mechanics
described in this paper may be used to obtain quantum solutions with a modest
increase in effort compared to semiclassical calculations. We also describe and
apply a method for obtaining leading quantum corrections to EBK results.
Finally, we suggest several new or modified applications of EBK quantization.Comment: 37 pages including 3 poscript figures, submitted to Phys. Rev.
Five Kepler target stars that show multiple transiting exoplanet candidates
We present and discuss five candidate exoplanetary systems identified with
the Kepler spacecraft. These five systems show transits from multiple exoplanet
candidates. Should these objects prove to be planetary in nature, then these
five systems open new opportunities for the field of exoplanets and provide new
insights into the formation and dynamical evolution of planetary systems. We
discuss the methods used to identify multiple transiting objects from the
Kepler photometry as well as the false-positive rejection methods that have
been applied to these data. One system shows transits from three distinct
objects while the remaining four systems show transits from two objects. Three
systems have planet candidates that are near mean motion
commensurabilities---two near 2:1 and one just outside 5:2. We discuss the
implications that multitransiting systems have on the distribution of orbital
inclinations in planetary systems, and hence their dynamical histories; as well
as their likely masses and chemical compositions. A Monte Carlo study indicates
that, with additional data, most of these systems should exhibit detectable
transit timing variations (TTV) due to gravitational interactions---though none
are apparent in these data. We also discuss new challenges that arise in TTV
analyses due to the presence of more than two planets in a system.Comment: Accepted to Ap
Development of recurrent coastal plume in Lake Michigan observed for first time
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94637/1/eost11132.pd
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