Neutrino Physics

The basic concepts of neutrino physics are presented at a level appropriate for integration into elementary courses on quantum mechanics and/or modern physics.Comment: Prepared for the American Journal of Physics; 50 pages; 11 figures (10 included); late

Quantum states prepared by realistic entanglement swapping

Entanglement swapping between photon pairs is a fundamental building block in schemes using quantum relays or quantum repeaters to overcome the range limits of long-distance quantum key distribution. We develop a closed-form solution for the actual quantum states prepared by realistic entanglement swapping, which takes into account experimental deficiencies due to inefficient detectors, detector dark counts, and multiphoton-pair contributions of parametric down-conversion sources. We investigate how the entanglement present in the final state of the remaining modes is affected by the real-world imperfections. To test the predictions of our theory, comparison with previously published experimental entanglement swapping is provided.Comment: 44 pages, 7 figures, Published with minor changes in Phys. Rev.

Differential Evolution for Many-Particle Adaptive Quantum Metrology

We devise powerful algorithms based on differential evolution for adaptive many-particle quantum metrology. Our new approach delivers adaptive quantum metrology policies for feedback control that are orders-of-magnitude more efficient and surpass the few-dozen-particle limitation arising in methods based on particle-swarm optimization. We apply our method to the binary-decision-tree model for quantum-enhanced phase estimation as well as to a new problem: a decision tree for adaptive estimation of the unknown bias of a quantum coin in a quantum walk and show how this latter case can be realized experimentally.Comment: Fig. 2(a) is the cover of Physical Review Letters Vol. 110 Issue 2

Placenta Ingestion Enhances Analgesia\ud Produced by Vaginal/Cervical\ud Stimulation in Rats

Ingestion of placenta has previously been shown to enhance opiate-mediated analgesia (measured as tail-flick latency) induced either by morphine injection or by footshock. The present study was designed to test whether placenta ingestion would enhance the partly opiate-mediated analgesia produced by vaginal/cervical stimulation. Nulliparous Sprague-Dawley rats were tested for analgesia, using tail-flick latency, during and after vaginal/cervical stimulation; the tests for vaginal/cervical stimulation-induced analgesia were administered both before and after the rats ate placenta or ground beef. Placenta ingestion, but not beef ingestion. significantly heightened vaginal/cervical stimulation-induced analgesia. A subsequent morphine injection provided evidence that, as in a previous report, placenta ingestion, but not beef ingestion, enhanced morphine-induced analgesia

Ordered Measurements of Permutationally-Symmetric Qubit Strings

We show that any sequence of measurements on a permutationally-symmetric (pure or mixed) multi-qubit string leaves the unmeasured qubit substring also permutationally-symmetric. In addition, we show that the measurement probabilities for an arbitrary sequence of single-qubit measurements are independent of how many unmeasured qubits have been lost prior to the measurement. Our results are valuable for quantum information processing of indistinguishable particles by post-selection, e.g. in cases where the results of an experiment are discarded conditioned upon the occurrence of a given event such as particle loss. Furthermore, our results are important for the design of adaptive-measurement strategies, e.g. a series of measurements where for each measurement instance, the measurement basis is chosen depending on prior measurement results.Comment: 13 page

Large-eddy simulation with accurate implicit subgrid-scale diffusion

A method for large-eddy simulation is presented that does not use an explicit subgrid-scale diffusion term. Subgrid-scale effects are modelled implicitly through an appropriate monotone (in the sense of Spekreijse 1987) discretization method for the advective terms. Special attention is given to the accuracy of the implicit subgrid-scale diffusion term. Computational results are shown for the dispersion of a passive scalar in an artificial turbulent velocity field. Comparisons are made with standard large-eddy simulation results. From the viewpoint of accuracy and computational costs the results ar

Limited access orders in the developing world :a new approach to the problems of development

The upper-income, advanced industrial countries of the world today all have market economies with open competition, competitive multi-party democratic political systems, and a secure government monopoly over violence. Such open access orders, however, are not the only norm and equilibrium type of society. The middle and low-income developing countries today, like all countries before about 1800, can be understood as limited access orders that maintain their equilibrium in a fundamentally different way. In limited access orders, the state does not have a secure monopoly on violence, and society organizes itself to control violence among the elite factions. A common feature of limited access orders is that political elites divide up control of the economy, each getting some share of the rents. Since outbreaks of violence reduce the rents, the elite factions have incentives to be peaceable most of the time. Adequate stability of the rents and thus of the social order requires limiting access and competition-hence a social order with a fundamentally different logic than the open access order. This paper lays out such a framework and explores some of its implications for the problems of development today.Corporate Law,Labor Policies,Public Sector Corruption&Anticorruption Measures,E-Business,Disability