683 research outputs found

    Maximally epistemic interpretations of the quantum state and contextuality

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    We examine the relationship between quantum contextuality (in both the standard Kochen-Specker sense and in the generalised sense proposed by Spekkens) and models of quantum theory in which the quantum state is maximally epistemic. We find that preparation noncontextual models must be maximally epistemic, and these in turn must be Kochen-Specker noncontextual. This implies that the Kochen-Specker theorem is sufficient to establish both the impossibility of maximally epistemic models and the impossibility of preparation noncontextual models. The implication from preparation noncontextual to maximally epistemic then also yields a proof of Bell's theorem from an EPR-like argument.Comment: v1: 4 pages, revTeX4.1, some overlap with arXiv:1207.7192. v2: Changes in response to referees including revised proof of theorem 1, more rigorous discussion of measure theoretic assumptions and extra introductory materia

    Design, development and evaluation of Stanford/Ames EVA prehensors

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    Space Station operations and maintenance are expected to make unprecedented demands on astronaut EVA. With Space Station expected to operate with an 8 to 10 psi atmosphere (4 psi for Shuttle operations), the effectivness of pressurized gloves is called into doubt at the same time that EVA activity levels are to be increased. To address the need for more frequent and complex EVA missions and also to extend the dexterity, duration, and safety of EVA astronauts, NASA Ames and Stanford University have an ongoing cooperative agreement to explore and compare alternatives. This is the final Stanford/Ames report on manually powered Prehensors, each of which consists of a shroud forming a pressure enclosure around the astronaut's hand, and a linkage system to transfer the motions and forces of the hand to mechanical digits attached to the shroud. All prehensors are intended for attachment to a standard wrist coupling, as found on the AX-5 hard suit prototype, so that realistic tests can be performed under normal and reduced gravity as simulated by water flotation

    Design, development and evaluation of Stanford/Ames Extra-Vehicular Activity (EVA) prehensors

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    A summary is given of progress to date on work proposed in 1983 and continued in 1985, including design iterations on three different types of manually powered prehensors, construction of functional mockups of each and culminating in detailed drawings and specifications for suit-compatible sealed units for testing under realistic conditions

    Measuring Polynomial Invariants of Multi-Party Quantum States

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    We present networks for directly estimating the polynomial invariants of multi-party quantum states under local transformations. The structure of these networks is closely related to the structure of the invariants themselves and this lends a physical interpretation to these otherwise abstract mathematical quantities. Specifically, our networks estimate the invariants under local unitary (LU) transformations and under stochastic local operations and classical communication (SLOCC). Our networks can estimate the LU invariants for multi-party states, where each party can have a Hilbert space of arbitrary dimension and the SLOCC invariants for multi-qubit states. We analyze the statistical efficiency of our networks compared to methods based on estimating the state coefficients and calculating the invariants.Comment: 8 pages, 4 figures, RevTex4, v2 references update

    A generalized no-broadcasting theorem

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    We prove a generalized version of the no-broadcasting theorem, applicable to essentially \emph{any} nonclassical finite-dimensional probabilistic model satisfying a no-signaling criterion, including ones with ``super-quantum'' correlations. A strengthened version of the quantum no-broadcasting theorem follows, and its proof is significantly simpler than existing proofs of the no-broadcasting theorem.Comment: 4 page

    Enhancement of the Binding Energy of Charged Excitons in Disordered Quantum Wires

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    Negatively and positively charged excitons are identified in the spatially-resolved photoluminescence spectra of quantum wires. We demonstrate that charged excitons are weakly localized in disordered quantum wires. As a consequence, the enhancement of the "binding energy" of a charged exciton is caused, for a significant part, by the recoil energy transferred to the remaining charged carrier during its radiative recombination. We discover that the Coulomb correlation energy is not the sole origin of the "binding energy", in contrast to charged excitons confined in quantum dots.Comment: 4 Fig

    Giant cell carcinoma of the lung successfully treated with surgical resection and adjuvant vinorelbine and cisplatin

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    © 2018 Giant Cell Carcinoma of the lung, a subtype of Sarcomatoid lung cancer is a poorly differentiated Non-Small-Cell Lung Cancer. GCCL has exceptionally aggressive characteristics, and its prognosis is much poorer than any other NSCLCs. Herein, we present a rare case of Giant Cell Carcinoma of lung treated successfully with surgical resection and adjuvant vinorelbine and cisplatin. A 48-year-old African American man with a history of smoking and chronic obstructive pulmonary disease was admitted to the hospital for chief complaints of shortness of breath. He was found to have a 3.5 cm × 3.3 cm x 2.8 cm cavitary right upper lobe mass which turned out to be poorly differentiated Giant Cell Carcinoma with extensive necrosis and deemed similar to stage 1b non-small cell lung cancer. He was successfully treated with right upper lobectomy and adjuvant chemotherapy with vinorelbine and cisplatin. He was followed for seven years with no evidence of recurrent disease. Giant Cell Carcinoma\u27s existing literature is limited, and hence our case is reportable. Our case is unique because of the better outcome which we believe might be the result of early detection and treatment with surgical resection along with adjuvant chemotherapy. More studies are needed to deeply understand the need for adjuvant chemotherapy in stage 1 b GCCL, and proper guidelines are required for the indications of adjuvant chemotherapy in Stage 1b GCCL

    Superrelativity as a unification of quantum theory and relativity(II)

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    A underlying dynamical structure for both relativity and quantum theory-``superrelativity'' has been proposed in order to overcome the well known incompatibility between these theories. The relationship between curvature of spacetime (gravity) and curvature of the projective Hilbert space of pure quantum states is established as well.Comment: 6 pages,LaTeX,In the Abstract ``proposed on order'' should be read as ``proposed in order'

    Demonstration of a Near-IR Laser Comb for Precision Radial Velocity Measurements in Astronomy

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    We describe a successful effort to produce a laser comb around 1.55 ÎĽ\mum in the astronomical H band using a method based on a line-referenced, electro-optical-modulation frequency comb. We discuss the experimental setup, laboratory results, and proof of concept demonstrations at the NASA Infrared Telescope Facility (IRTF) and the Keck-II telescope. The laser comb has a demonstrated stability of << 200 kHz, corresponding to a Doppler precision of ~0.3 m/s. This technology, when coupled with a high spectral resolution spectrograph, offers the promise of <<1 m/s radial velocity precision suitable for the detection of Earth-sized planets in the habitable zones of cool M-type stars

    Bell's Jump Process in Discrete Time

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    The jump process introduced by J. S. Bell in 1986, for defining a quantum field theory without observers, presupposes that space is discrete whereas time is continuous. In this letter, our interest is to find an analogous process in discrete time. We argue that a genuine analog does not exist, but provide examples of processes in discrete time that could be used as a replacement.Comment: 7 pages LaTeX, no figure
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