5,101 research outputs found
Detection of quantum light in the presence of noise
Detection of quantum light in the presence of dark counts and background
radiation noise is considered. The corresponding positive operator-valued
measure is obtained and photocounts statistics of quantum light in the presence
of noise is studied.Comment: 4 pages, 1 figure; misprints correcte
The Effect of Span and Deflection of Split Flaps and Leading-edge Roughness on the Longitudinal Stability and Gliding Characteristics of a 42 Degree Sweptback Wing Equipped with Leading-edge Flaps
Effects of plain and step spoiler location and projection on the lateral control characteristics of a plain and flapped 42 degree sweptback wing at a Reynolds number of 6.8 x 10(exp 6)
A system of relational syllogistic incorporating full Boolean reasoning
We present a system of relational syllogistic, based on classical
propositional logic, having primitives of the following form:
Some A are R-related to some B;
Some A are R-related to all B;
All A are R-related to some B;
All A are R-related to all B.
Such primitives formalize sentences from natural language like `All students
read some textbooks'. Here A and B denote arbitrary sets (of objects), and R
denotes an arbitrary binary relation between objects. The language of the logic
contains only variables denoting sets, determining the class of set terms, and
variables denoting binary relations between objects, determining the class of
relational terms. Both classes of terms are closed under the standard Boolean
operations. The set of relational terms is also closed under taking the
converse of a relation. The results of the paper are the completeness theorem
with respect to the intended semantics and the computational complexity of the
satisfiability problem.Comment: Available at
http://link.springer.com/article/10.1007/s10849-012-9165-
Exploring the nuclear pion dispersion relation through the anomalous coupling of photon to photon and neutral pion
We investigate the possibility of measuring the pion dispersion relation in
nuclear matter through the anomalous coupling in the reaction \gamma - \gamma'
\pi_0. It is shown that this reaction permits the study of pionic modes for
space-like momenta. If the pion is softened in nuclear matter due to mixing
with the delta-hole state, significant strength for this reaction is expected
to move into the space-like region. Competing background processes are
evaluated, and it is concluded that useful insight can be obtained
experimentally, but only through a difficult exclusive measurement
Quantum corrections for pion correlations involving resonance decays
A method is presented to include quantum corrections into the calculation of
two-pion correlations for the case where particles originate from resonance
decays. The technique uses classical information regarding the space-time
points at which resonances are created. By evaluating a simple thermal model,
the method is compared to semiclassical techniques that assume exponential
decaying resonances moving along classical trajectories. Significant
improvements are noted when the resonance widths are broad as compared to the
temperature.Comment: 9 pages, 4 figure
Two-photon correlations as a sign of sharp transition in quark-gluon plasma
The photon production arising due to time variation of the medium has been
considered. The Hamilton formalism for photons in time-variable medium (plasma)
has been developed with application to inclusive photon production. The results
have been used for calculation of the photon production in the course of
transition from quark-gluon phase to hadronic phase in relativistic heavy ion
collisions. The relative strength of the effect as well as specific two- photon
correlations have been evaluated. It has been demonstrated that the opposite
side two-photon correlations are indicative of the sharp transition from the
quark-gluon phase to hadrons.Comment: 23 pages, 2 figure
Robustness of superconductivity to competing magnetic phases in tetragonal FeS
We have determined the superconducting and magnetic properties of a
hydrothermally synthesized powder sample of tetragonal FeS using muon spin
rotation ({\mu}SR). The superconducting properties are entirely consistent with
those of a recently published study, showing fully gapped behavior and giving a
penetration depth of {\lambda}_{ab} = 204(3) nm. However, our zero-field
{\mu}SR data are rather different and indicate the presence of a small,
non-superconducting magnetic phase within the sample. These results highlight
that sample-to-sample variations in magnetism can arise in hydrothermally
prepared phases, but interestingly the superconducting behavior is remarkably
insensitive to these variations.Comment: 5 pages, 2 figure
Solving order constraints in logarithmic space.
We combine methods of order theory, finite model theory, and universal algebra to study, within the constraint satisfaction framework, the complexity of some well-known combinatorial problems connected with a finite poset. We identify some conditions on a poset which guarantee solvability of the problems in (deterministic, symmetric, or non-deterministic) logarithmic space. On the example of order constraints we study how a certain algebraic invariance property is related to solvability of a constraint satisfaction problem in non-deterministic logarithmic space
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