107,297 research outputs found

    Superluminal hidden communication as the underlying mechanism for quantum correlations: constraining models

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    Since Bell's theorem, it is known that quantum correlations cannot be described by local variables (LV) alone: if one does not want to abandon classical mechanisms for correlations, a superluminal form of communication among the particles must be postulated. A natural question is whether such a postulate would imply the possibility of superluminal signaling. Here we show that the assumption of finite-speed superluminal communication indeed leads to signaling when no LV are present, and more generally when only LV derivable from quantum statistics are allowed. When the most general LV are allowed, we prove in a specific case that the model can be made again consistent with relativity, but the question remains open in general.Comment: 5 pages, 1 figure. For the Proceedings of the Conference DICE 2004 (Piombino, 1-4 Sept. 2004

    Extra virgin olive oil use is associated with improved post-prandial blood glucose and LDL cholesterol in healthy subjects

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    Extra virgin olive oil (EVOO) is a key component of the Mediterranean diet and seems to account for the protective effect against cardiovascular disease. However, the underlying mechanism is still elusive

    Deriving an underlying mechanism for discontinuous percolation

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    Understanding what types of phenomena lead to discontinuous phase transitions in the connectivity of random networks is an outstanding challenge. Here we show that a simple stochastic model of graph evolution leads to a discontinuous percolation transition and we derive the underlying mechanism responsible: growth by overtaking. Starting from a collection of nn isolated nodes, potential edges chosen uniformly at random from the complete graph are examined one at a time while a cap, kk, on the maximum allowed component size is enforced. Edges whose addition would exceed kk can be simply rejected provided the accepted fraction of edges never becomes smaller than a function which decreases with kk as g(k)=1/2+(2k)−βg(k) = 1/2 + (2k)^{-\beta}. We show that if β<1\beta < 1 it is always possible to reject a sampled edge and the growth in the largest component is dominated by an overtaking mechanism leading to a discontinuous transition. If β>1\beta > 1, once k≥n1/βk \ge n^{1/\beta}, there are situations when a sampled edge must be accepted leading to direct growth dominated by stochastic fluctuations and a "weakly" discontinuous transition. We also show that the distribution of component sizes and the evolution of component sizes are distinct from those previously observed and show no finite size effects for the range of β\beta studied.Comment: 6 pages. Final version appearing in EPL (2012

    Elliptical Trajectories in Nonsequential Double Ionization

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    Using a classical ensemble method, nonsequential double ionization is predicted to exist with elliptical and circular polarization. Recollision is found to be the underlying mechanism and it is only possible via elliptical trajectories.Comment: Submitted to New Journal of Physic

    Tako-tsubo cardiomyopathy: Clinical presentation and underlying mechanism

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    AbstractSince Dr Sato at Hiroshima City Hospital first recognized and reported the concept of tako-tsubo cardiomyopathy in 1990, this disorder has become accepted worldwide as a distinct clinical entity. Tako-tsubo cardiomyopathy is an important disorder as a differential diagnosis of acute myocardial infarction. This disorder usually occurs in postmenopausal women of an advanced age, and is characterized by transient left ventricular apical wall motion abnormalities associated with emotional or physical stress. Typically, left ventricular apical wall motion abnormalities are transient and resolve during a period of days to weeks. The prognosis is generally favorable. However, several acute complications have been reported such as congestive heart failure, cardiac rupture, hypotension, left ventricular apical thrombosis, or Torsade de Pointes. Several possible mechanisms such as multivessel coronary artery spasm, coronary microvascular dysfunction, myocarditis, or catecholamine toxicity have been proposed to explain tako-tsubo cardiomyopathy, but its pathophysiology is not well understood

    Universality of underlying mechanism for successful deep learning

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    An underlying mechanism for successful deep learning (DL) with a limited deep architecture and dataset, namely VGG-16 on CIFAR-10, was recently presented based on a quantitative method to measure the quality of a single filter in each layer. In this method, each filter identifies small clusters of possible output labels, with additional noise selected as labels out of the clusters. This feature is progressively sharpened with the layers, resulting in an enhanced signal-to-noise ratio (SNR) and higher accuracy. In this study, the suggested universal mechanism is verified for VGG-16 and EfficientNet-B0 trained on the CIFAR-100 and ImageNet datasets with the following main results. First, the accuracy progressively increases with the layers, whereas the noise per filter typically progressively decreases. Second, for a given deep architecture, the maximal error rate increases approximately linearly with the number of output labels. Third, the average filter cluster size and the number of clusters per filter at the last convolutional layer adjacent to the output layer are almost independent of the number of dataset labels in the range [3, 1,000], while a high SNR is preserved. The presented DL mechanism suggests several techniques, such as applying filter's cluster connections (AFCC), to improve the computational complexity and accuracy of deep architectures and furthermore pinpoints the simplification of pre-existing structures while maintaining their accuracies.Comment: 27 pages,5 figures, 6 tables. arXiv admin note: text overlap with arXiv:2305.1807

    Edge states of a three dimensional kicked rotor

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    Edge localization is a fascinating quantum phenomenon. In this paper, the underlying mechanism generating it is presented analytically and verified numerically for a weakly kicked three-dimensional rotor. Analogy to tight binding model in solid state physics is used. The edge states result of the edge at zero angular momentum of the three-dimensional kicked rotor.Comment: 16 pages, 3 figure
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