32,285 research outputs found
Proving termination of evaluation for System F with control operators
We present new proofs of termination of evaluation in reduction semantics
(i.e., a small-step operational semantics with explicit representation of
evaluation contexts) for System F with control operators. We introduce a
modified version of Girard's proof method based on reducibility candidates,
where the reducibility predicates are defined on values and on evaluation
contexts as prescribed by the reduction semantics format. We address both
abortive control operators (callcc) and delimited-control operators (shift and
reset) for which we introduce novel polymorphic type systems, and we consider
both the call-by-value and call-by-name evaluation strategies.Comment: In Proceedings COS 2013, arXiv:1309.092
Coherent population trapping resonances with linearly polarized light for all-optical miniature atomic clocks
We present a joint theoretical and experimental characterization of the
coherent population trapping (CPT) resonance excited on the D1 line of 87Rb
atoms by bichromatic linearly polarized laser light. We observe high-contrast
transmission resonances (up to 25%), which makes this excitation scheme
promising for miniature all-optical atomic clock applications. We also
demonstrate cancellation of the first-order light shift by proper choice of the
frequencies and relative intensities of the two laser field components. Our
theoretical predictions are in good agreement with the experimental results.Comment: 8 pages, 7 figure
Summary of the 13th IACHEC Meeting
We summarize the outcome of the 13th meeting of the International
Astronomical Consortium for High Energy Calibration (IACHEC), held at Tenuta
dei Ciclamini (Avigliano Umbro, Italy) in April 2018. Fifty-one scientists
directly involved in the calibration of operational and future high-energy
missions gathered during 3.5 days to discuss the current status of the X-ray
payload inter-calibration and possible approaches to improve it. This summary
consists of reports from the various working groups with topics ranging from
the identification and characterization of standard calibration sources,
multi-observatory cross-calibration campaigns, appropriate and new statistical
techniques, calibration of instruments and characterization of background, and
communication and preservation of knowledge and results for the benefit of the
astronomical community.Comment: 12 page
Probabilistic theories with purification
We investigate general probabilistic theories in which every mixed state has
a purification, unique up to reversible channels on the purifying system. We
show that the purification principle is equivalent to the existence of a
reversible realization of every physical process, namely that every physical
process can be regarded as arising from a reversible interaction of the system
with an environment, which is eventually discarded. From the purification
principle we also construct an isomorphism between transformations and
bipartite states that possesses all structural properties of the
Choi-Jamiolkowski isomorphism in quantum mechanics. Such an isomorphism allows
one to prove most of the basic features of quantum mechanics, like e.g.
existence of pure bipartite states giving perfect correlations in independent
experiments, no information without disturbance, no joint discrimination of all
pure states, no cloning, teleportation, no programming, no bit commitment,
complementarity between correctable channels and deletion channels,
characterization of entanglement-breaking channels as measure-and-prepare
channels, and others, without resorting to the mathematical framework of
Hilbert spaces.Comment: Differing from the journal version, this version includes a table of
contents and makes extensive use of boldface type to highlight the contents
of the main theorems. It includes a self-contained introduction to the
framework of general probabilistic theories and a discussion about the role
of causality and local discriminabilit
Bridging the gap between general probabilistic theories and the device-independent framework for nonlocality and contextuality
Characterizing quantum correlations in terms of information-theoretic
principles is a popular chapter of quantum foundations. Traditionally, the
principles adopted for this scope have been expressed in terms of conditional
probability distributions, specifying the probability that a black box produces
a certain output upon receiving a certain input. This framework is known as
"device-independent". Another major chapter of quantum foundations is the
information-theoretic characterization of quantum theory, with its sets of
states and measurements, and with its allowed dynamics. The different
frameworks adopted for this scope are known under the umbrella term "general
probabilistic theories". With only a few exceptions, the two programmes on
characterizing quantum correlations and characterizing quantum theory have so
far proceeded on separate tracks, each one developing its own methods and its
own agenda. This paper aims at bridging the gap, by comparing the two
frameworks and illustrating how the two programmes can benefit each other.Comment: 61 pages, no figures, published versio
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