34,535 research outputs found
Convolution and deconvolution based estimates of galaxy scaling relations from photometric redshift surveys
In addition to the maximum likelihood approach, there are two other methods
which are commonly used to reconstruct the true redshift distribution from
photometric redshift datasets: one uses a deconvolution method, and the other a
convolution. We show how these two techniques are related, and how this
relationship can be extended to include the study of galaxy scaling relations
in photometric datasets. We then show what additional information photometric
redshift algorithms must output so that they too can be used to study galaxy
scaling relations, rather than just redshift distributions. We also argue that
the convolution based approach may permit a more efficient selection of the
objects for which calibration spectra are required.Comment: 7 pages, 4 figures, accepted for publication in MNRAS; v2 includes a
new section and other minor change
Uncertainty in Soft Temporal Constraint Problems:A General Framework and Controllability Algorithms forThe Fuzzy Case
In real-life temporal scenarios, uncertainty and preferences are often
essential and coexisting aspects. We present a formalism where quantitative
temporal constraints with both preferences and uncertainty can be defined. We
show how three classical notions of controllability (that is, strong, weak, and
dynamic), which have been developed for uncertain temporal problems, can be
generalized to handle preferences as well. After defining this general
framework, we focus on problems where preferences follow the fuzzy approach,
and with properties that assure tractability. For such problems, we propose
algorithms to check the presence of the controllability properties. In
particular, we show that in such a setting dealing simultaneously with
preferences and uncertainty does not increase the complexity of controllability
testing. We also develop a dynamic execution algorithm, of polynomial
complexity, that produces temporal plans under uncertainty that are optimal
with respect to fuzzy preferences
Spatially dependent Kondo effect in Quantum Corrals
We study the Kondo screening of a single magnetic impurity inside a
non-magnetic quantum corral located on the surface of a metallic host system.
We show that the spatial structure of the corral's eigenmodes lead to a
spatially dependent Kondo effect whose signatures are spatial variations of the
Kondo temperature, . Moreover, we predict that the Kondo screening is
accompanied by the formation of multiple Kondo resonances with characteristic
spatial patterns. Our results open new possibilities to manipulate and explore
the Kondo effect by using quantum corrals.Comment: 4 pages 5 figure
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