46,665 research outputs found
Fractal templates in the escape dynamics of trapped ultracold atoms
We consider the dynamic escape of a small packet of ultracold atoms launched
from within an optical dipole trap. Based on a theoretical analysis of the
underlying nonlinear dynamics, we predict that fractal behavior can be seen in
the escape data. This data would be collected by measuring the time-dependent
escape rate for packets launched over a range of angles. This fractal pattern
is particularly well resolved below the Bose-Einstein transition temperature--a
direct result of the extreme phase space localization of the condensate. We
predict that several self-similar layers of this novel fractal should be
measurable and we explain how this fractal pattern can be predicted and
analyzed with recently developed techniques in symbolic dynamics.Comment: 11 pages with 5 figure
Zero-loss/deflection map analysis
Experimental plots of the fraction of detected electrons removed from the
zero-loss peak, versus the fraction of incident electrons scattered outside of
the objective aperture, can serve as a robust fingerprint of object-contrast in
an energy filtered transmission electron microscope (EFTEM). Examples of this,
along with the first in a series of models for interpreting the resulting
patterns, were presented at the August 2010 meeting of the Microscope Society
of America meeting in Portland, Oregon, and published in {\em Microscopy and
MicroAnalysis} {\bf 16}, Supplement 2, pages 1534-1535 by Cambridge University
Press.Comment: 3 pages (3 figs, 4 refs) RevTeX, cf.
http://www.umsl.edu/~fraundorfp/zldeflmaps.htm
Economic Impact Assessment: the creative sector in the Western Region
Introduction.
Developments around the globe are re-defining media, arts and other related sectors as
‘creative industries’ which are being recognised for their potential impact on local and
national economies. This economic impact assessment builds on previous work
commissioned by the Western Development Commission and contends that artistic and
cultural activities are not simple by-products of a developed economy but essential elements
of economic success and sustainability. Such activities represent alternate forms of
expression of human creativity that encourage lateral thinking and thus complement
scientific and technological innovation. As we will see, these activities lie at the core of a
number of growing sectors in the region, and contribute directly to employment growth and
wealth creation2.
Internationally, the case for fostering the creative economy is a convincing one. In the ten
years up to 2005, the creative economy grew at twice the annual rate of the service
industries and four times the rate of manufacturing in OECD countries3. In Europe, the
growth of the cultural and creative sector was 12.3% higher than the growth of the overall
economy from 1999 to 2003. From an economic perspective, international trade is a key
component, from 2000 – 2005, trade in creative-industry products grew on average by 8.7%
annually. These figures have grabbed the attention of policy makers here and abroad.
This report was commissioned by the Western Development Commission (WDC) in July 2010
to consider the economic impact of the Creative Economy in the Western Region of Ireland4.
It builds on previous work carried out by Oxford Economics and the WDC. That work,
published as the Creative West document in early 2009 informed a great deal of debate at
the regional and national level. This work attempts to add a dynamic element to what was a
snapshot of the sector
Derivation of the Gauge Link in Light Cone Gauge
In light cone gauge, a gauge link at light cone infinity is necessary for
transverse momentum-dependent parton distribution to restore the gauge
invariance in some specific boundary conditions. We derive such transverse
gauge link in a more regular and general method. We find the gauge link at
light cone infinity naturally arises from the contribution of the pinched
poles: one is from the quark propagator and the other is hidden in the gauge
vector field in light cone gauge. Actually, in the amplitude level, we have
obtained a more general gauge link over the hypersurface at light cone infinity
which is beyond the transverse direction. The difference of such gauge link
between semi-inclusive deep inelastic scattering and Drell-Yan processes can
also be obtained directly and clearly in our derivation.Comment: 18 pages, 5 figures, published versio
An evaluation of the suitability of ERTS data for the purposes of petroleum exploration
This experiment was designed to determine the types and amounts of information valuable to petroleum exploration extractable from ERTS data and the cost of obtaining the information using traditional or conventional means. It was desired that an evaluation of this new petroleum exploration tool be made in a geologically well known area in order to assess its usefulness in an unknown area. The Anadarko Basin lies in western Oklahoma and the panhandle of Texas. It was chosen as a test site because there is a great deal of published information available on the surface and subsurface geology of the area, and there are many known structures that act as traps for hydrocarbons. This basin is similar to several other large epicontinental sedimentary basins. It was found that ERTS imagery is an excellent tool for reconnaissance exploration of large sedimentary basins or new exploration provinces. For the first time, small and medium size oil companies can rapidly and effectively analyze exploration provinces as a whole
Programmable networks for quantum algorithms
The implementation of a quantum computer requires the realization of a large
number of N-qubit unitary operations which represent the possible oracles or
which are part of the quantum algorithm. Until now there are no standard ways
to uniformly generate whole classes of N-qubit gates. We have developed a
method to generate arbitrary controlled phase shift operations with a single
network of one-qubit and two-qubit operations. This kind of network can be
adapted to various physical implementations of quantum computing and is
suitable to realize the Deutsch-Jozsa algorithm as well as Grover's search
algorithm.Comment: 4 pages. Accepted version; Journal-ref. adde
The Transversity Function and Double Spin Azimuthal Asymmetry in Semi-Inclusive Pion Leptoproduction
We show that the transverse momentum dependent transversity function is
proportional to the longitudinal polarization of a quark in a transversely
polarized proton. This result suggests an alternative, convenient method for
determining transversity, without knowing unusual fragmentation functions. The
method consists of measuring the double spin azimuthal asymmetry in
semi-inclusive pion leptoproduction by a transversely polarized proton target.
The asymmetry, which is twist 3, is estimated to be more than 10% under the
most favorable conditions. The experiment we suggest is feasible at facilities
like DESY and CERN.Comment: extended version; to appear on Int. Jou. Mod. Phys.
Non-Markovian Stochastic Resonance
The phenomenological linear response theory of non-Markovian Stochastic
Resonance (SR) is put forward for stationary two-state renewal processes. In
terms of a derivation of a non-Markov regression theorem we evaluate the
characteristic SR-quantifiers; i.e. the spectral power amplification (SPA) and
the signal-to-noise ratio (SNR), respectively. In clear contrast to Markovian
SR, a characteristic benchmark of genuine non-Markovian SR is its distinctive
dependence of the SPA and SNR on small (adiabatic) driving frequencies;
particularly, the adiabatic SNR becomes strongly suppressed over its Markovian
counterpart. This non-Markovian SR theory is elucidated for a fractal gating
dynamics of a potassium ion channel possessing an infinite variance of closed
sojourn times.Comment: 4 pages, 1 figur
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