5,072 research outputs found
On the response of a particle detector in Anti-de Sitter spacetime
We consider the vacuum response of a particle detector in Anti-de Sitter
spacetime, and in particular analyze how spacetime features such as curvature
and dimensionality affect the response spectrum of an accelerated detector. We
calculate useful limits on Wightman functions, analyze the dynamics of the
detector in terms of vacuum fluctuations and radiation reactions, and discuss
the thermalization process for the detector. We also present a generalization
of the GEMS approach and obtain the Gibbons-Hawking temperature of de Sitter
spacetime as an embedded Unruh temperature in a curved Anti-de Sitter
spacetime.Comment: 13 pages, no figures, accepted for publication in Class. Quantum Gra
Status of the Standard Solar Model Prediction of Solar Neutrino Fluxes
The Standard Solar Model (BP04) predicts a total 8B neutrino flux that is
17.2% larger than measured in the salt phase of the SNO detector (and if it
were significant it will indicate oscillation to sterile neutrinos). Hence it
is important to examine in details uncertainties (and values) of inputs to the
SSM. Currently, the largest fractional uncertainty is due to the new evaluation
of the surface composition of the sun. We examine the nuclear input on the
formation of solar 8B [S17(0)] and demonstrate that it is still quite uncertain
due to ill known slope of the measured astrophysical cross section factor and
thus ill defined extrapolation to zero energy. This yields an additional
reasonably estimated uncertainty due to extrapolation of +0.0 -3.0 eV-b (+0%
-14%). Since a large discrepancy exists among measured as well as among
predicted slopes, the value of S17(0) is dependent on the choice of data and
theory used to extrapolate S17(0). This situation must be alleviated by new
measurement(s). The "world average" is driven by the Seattle result due to the
very small quoted uncertainty, which we however demonstrate it to be an
over-estimated accuracy. We propose more realistic error bars for the Seattle
results based on the published Seattle data.Comment: Fifth International Conferenceon Non-Accelerator New Physics, Dubna,
June 20-25, 2005. Work Supported by USDOE Grant No. DE-FG02-94ER4087
The position profiles of order cancellations in an emerging stock market
Order submission and cancellation are two constituent actions of stock
trading behaviors in order-driven markets. Order submission dynamics has been
extensively studied for different markets, while order cancellation dynamics is
less understood. There are two positions associated with a cancellation, that
is, the price level in the limit-order book (LOB) and the position in the queue
at each price level. We study the profiles of these two order cancellation
positions through rebuilding the limit-order book using the order flow data of
23 liquid stocks traded on the Shenzhen Stock Exchange in the year 2003. We
find that the profiles of relative price levels where cancellations occur obey
a log-normal distribution. After normalizing the relative price level by
removing the factor of order numbers stored at the price level, we find that
the profiles exhibit a power-law scaling behavior on the right tails for both
buy and sell orders. When focusing on the order cancellation positions in the
queue at each price level, we find that the profiles increase rapidly in the
front of the queue, and then fluctuate around a constant value till the end of
the queue. These profiles are similar for different stocks. In addition, the
profiles of cancellation positions can be fitted by an exponent function for
both buy and sell orders. These two kinds of cancellation profiles seem
universal for different stocks investigated and exhibit minor asymmetry between
buy and sell orders. Our empirical findings shed new light on the order
cancellation dynamics and pose constraints on the construction of order-driven
stock market models.Comment: 17 pages, 6 figures and 6 table
Status of the Whipple Observatory Cerenkov air shower imaging telescope array
Recently the power of the Cerenkov imaging technique in Very High Energy gamma-ray astronomy was demonstrated by the detection of the Crab nebula at high statistical significance. In order to further develop this technique to allow the detection of weaker or more distant sources a second 10 m class reflector was constructed about 120 m from the original instrument. The addition of the second reflector will allow both a reduction in the energy threshold and an improvement in the rejection of the hadronic background. The design and construction of the second reflector, Gamma Ray Astrophysics New Imaging TElescope (GRANITE) is described
Bias in the journal impact factor
The ISI journal impact factor (JIF) is based on a sample that may represent
half the whole-of-life citations to some journals, but a small fraction (<10%)
of the citations accruing to other journals. This disproportionate sampling
means that the JIF provides a misleading indication of the true impact of
journals, biased in favour of journals that have a rapid rather than a
prolonged impact. Many journals exhibit a consistent pattern of citation
accrual from year to year, so it may be possible to adjust the JIF to provide a
more reliable indication of a journal's impact.Comment: 9 pages, 8 figures; one reference correcte
Product assurance technology for custom LSI/VLSI electronics
The technology for obtaining custom integrated circuits from CMOS-bulk silicon foundries using a universal set of layout rules is presented. The technical efforts were guided by the requirement to develop a 3 micron CMOS test chip for the Combined Release and Radiation Effects Satellite (CRRES). This chip contains both analog and digital circuits. The development employed all the elements required to obtain custom circuits from silicon foundries, including circuit design, foundry interfacing, circuit test, and circuit qualification
Mean-field description of ground-state properties of drip-line nuclei. (I) Shell-correction method
A shell-correction method is applied to nuclei far from the beta stability
line and its suitability to describe effects of the particle continuum is
discussed. The sensitivity of predicted locations of one- and two-particle drip
lines to details of the macroscopic-microscopic model is analyzed.Comment: 22 REVTeX pages, 13 uuencoded postscript figures available upon
reques
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