2,337 research outputs found

    Passive States for Essential Observers

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    The aim of this note is to present a unified approach to the results given in \cite{bb99} and \cite{bs04} which also covers examples of models not presented in these two papers (e.g. dd-dimensional Minkowski space-time for d3d\geq 3). Assuming that a state is passive for an observer travelling along certain (essential) worldlines, we show that this state is invariant under the isometry group, is a KMS-state for the observer at a temperature uniquely determined by the structure constants of the Lie algebra involved and fulfills (a variant of) the Reeh-Schlieder property. Also the modular objects associated to such a state and the observable algebra of an observer are computed and a version of weak locality is examined.Comment: 27 page

    Developing and validating an experience sampling measure of aggression:The Aggression-ES Scale

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    Experience sampling methodologies are likely to play an important role in advancing our understanding of momentary influences on aggression, including short-term antecedent psychological states and situations. In this study, we evaluate whether a newly developed experiencing sampling measure of aggression, the Aggression Experience Sampler (Aggression-ES), provides a valid and reliable measure of aggression in experience sampling contexts. Participants were a convenience sample of 23 young adults recruited from the local University community. Data were collected using an experience sampling smartphone application over 8 days. They were analyzed using multilevel structural equation modeling. Our results support the within- and between-person reliability and the criterion validity of the Aggression-ES. The Aggression-ES represents a good choice of measure for use in experience sampling studies of aggression. Further work in other samples will help to provide further validity evidence for the measure

    Diffraction of complex molecules by structures made of light

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    We demonstrate that structures made of light can be used to coherently control the motion of complex molecules. In particular, we show diffraction of the fullerenes C60 and C70 at a thin grating based on a standing light wave. We prove experimentally that the principles of this effect, well known from atom optics, can be successfully extended to massive and large molecules which are internally in a thermodynamic mixed state and which do not exhibit narrow optical resonances. Our results will be important for the observation of quantum interference with even larger and more complex objects.Comment: 4 pages, 3 figure

    A Constrained Path Monte Carlo Method for Fermion Ground States

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    We describe and discuss a recently proposed quantum Monte Carlo algorithm to compute the ground-state properties of various systems of interacting fermions. In this method, the ground state is projected from an initial wave function by a branching random walk in an over-complete basis of Slater determinants. By constraining the determinants according to a trial wave function ψT|\psi_T\rangle, we remove the exponential decay of signal-to-noise ratio characteristic of the sign problem. The method is variational and is exact if ψT|\psi_T\rangle is exact. We illustrate the method by describing in detail its implementation for the two-dimensional one-band Hubbard model. We show results for lattice sizes up to 16×1616\times 16 and for various electron fillings and interaction strengths. Besides highly accurate estimates of the ground-state energy, we find that the method also yields reliable estimates of other ground-state observables, such as superconducting pairing correlation functions. We conclude by discussing possible extensions of the algorithm.Comment: 29 pages, RevTex, 3 figures included; submitted to Phys. Rev.

    Antibiotic prophylaxis in anterior skull‐base surgery: a survey of the North American Skull Base Society

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151867/1/alr22396.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151867/2/alr22396_am.pd
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