770 research outputs found

    Dynamical locality of the nonminimally coupled scalar field and enlarged algebra of Wick polynomials

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    We discuss dynamical locality in two locally covariant quantum field theories, the nonminimally coupled scalar field and the enlarged algebra of Wick polynomials. We calculate the relative Cauchy evolution of the enlarged algebra, before demonstrating that dynamical locality holds in the nonminimally coupled scalar field theory. We also establish dynamical locality in the enlarged algebra for the minimally coupled massive case and the conformally coupled massive case.Comment: 39p

    A time-dependent perturbative analysis for a quantum particle in a cloud chamber

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    We consider a simple model of a cloud chamber consisting of a test particle (the alpha-particle) interacting with two other particles (the atoms of the vapour) subject to attractive potentials centered in a1,a2∈R3a_1, a_2 \in \mathbb{R}^3. At time zero the alpha-particle is described by an outgoing spherical wave centered in the origin and the atoms are in their ground state. We show that, under suitable assumptions on the physical parameters of the system and up to second order in perturbation theory, the probability that both atoms are ionized is negligible unless a2a_2 lies on the line joining the origin with a1a_1. The work is a fully time-dependent version of the original analysis proposed by Mott in 1929.Comment: 23 page

    The organizational dynamics enabling patient portal impacts upon organizational performance and patient health: A qualitative study of Kaiser Permanente

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    Background: Patient portals may lead to enhanced disease management, health plan retention, changes in channel utilization, and lower environmental waste. However, despite growing research on patient portals and their effects, our understanding of the organizational dynamics that explain how effects come about is limited. Methods

    A comprehensive study of the SX Phoenicis star BL Camelopardalis

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    Astronomy and Astrophysics, v. 451, p. 999-1008, 2006. http://dx.doi.org/10.1051/0004-6361:20053841International audienc

    WKB analysis for nonlinear Schr\"{o}dinger equations with potential

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    We justify the WKB analysis for the semiclassical nonlinear Schr\"{o}dinger equation with a subquadratic potential. This concerns subcritical, critical, and supercritical cases as far as the geometrical optics method is concerned. In the supercritical case, this extends a previous result by E. Grenier; we also have to restrict to nonlinearities which are defocusing and cubic at the origin, but besides subquadratic potentials, we consider initial phases which may be unbounded. For this, we construct solutions for some compressible Euler equations with unbounded source term and unbounded initial velocity.Comment: 25 pages, 11pt, a4. Appendix withdrawn, due to some inconsistencie

    An Algebraic Jost-Schroer Theorem for Massive Theories

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    We consider a purely massive local relativistic quantum theory specified by a family of von Neumann algebras indexed by the space-time regions. We assume that, affiliated with the algebras associated to wedge regions, there are operators which create only single particle states from the vacuum (so-called polarization-free generators) and are well-behaved under the space-time translations. Strengthening a result of Borchers, Buchholz and Schroer, we show that then the theory is unitarily equivalent to that of a free field for the corresponding particle type. We admit particles with any spin and localization of the charge in space-like cones, thereby covering the case of string-localized covariant quantum fields.Comment: 21 pages. The second (and crucial) hypothesis of the theorem has been relaxed and clarified, thanks to the stimulus of an anonymous referee. (The polarization-free generators associated with wedge regions, which always exist, are assumed to be temperate.

    The global wave front set of tempered oscillatory integrals with inhomogeneous phase functions

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    We study certain families of oscillatory integrals Iφ(a)I_\varphi(a), parametrised by phase functions φ\varphi and amplitude functions aa globally defined on Rd\mathbb{R}^d, which give rise to tempered distributions, avoiding the standard homogeneity requirement on the phase function. The singularities of Iφ(a)I_\varphi(a) are described both from the point of view of the lack of smoothness as well as with respect to the decay at infinity. In particular, the latter will depend on a version of the set of stationary points of φ\varphi, including elements lying at the boundary of the radial compactification of Rd\mathbb{R}^d. As applications, we consider some properties of the two-point function of a free, massive, scalar relativistic field and of classes of global Fourier integral operators on Rd\mathbb{R}^d, with the latter defined in terms of kernels of the form Iφ(a)I_\varphi(a).Comment: 30 pages, 2 figures, mistakes and typos correctio

    Theory of Current and Shot Noise Spectroscopy in Single-Molecular Quantum Dots with Phonon Mode

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    Using the Keldysh nonequilibrium Green function technique, we study the current and shot noise spectroscopy of a single molecular quantum dot coupled to a local phonon mode. It is found that in the presence of electron-phonon coupling, in addition to the resonant peak associated with the single level of the dot, satellite peaks with the separation set by the frequency of phonon mode appear in the differential conductance. In the ``single level'' resonant tunneling region, the differential shot noise power exhibit two split peaks. However, only single peaks show up in the ``phonon assisted'' resonant-tunneling region. An experimental setup to test these predictions is also proposed.Comment: 5 pages, 3 eps figures embedde

    On ecological conceptualizations of perceptual systems and action systems

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    This article examines Gibson's concept of perceptual system and Reed's concept of action system. After discussing several assumptions underlying these concepts, the ontological status of these systems is considered. It is argued that perceptual systems and action systems should be conceptualized neither as parts of an animal's body nor as softly (temporarily) assembled devices; rather, they are best understood as animals' abilities to achieve functional relationships, that is, as dispositional properties. This conceptualization entails that these systems are relatively permanent properties of the animal that are causally supported by, though not identical to, anatomical substrates. Further, it entails that it is the animal that perceives and acts, not its perceptual and action systems

    Characterization of the Atmosphere of the Hot Jupiter HAT-P-32Ab and the M-dwarf Companion HAT-P-32B

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    Copyright © 2015 IOP PublishingWe report secondary eclipse photometry of the hot Jupiter HAT-P-32Ab, taken with Hale/Wide-field Infra-Red Camera (WIRC) in H and KS bands and with Spitzer/IRAC at 3.6 and 4.5 μm. We carried out adaptive optics imaging of the planet host star HAT-P-32A and its companion HAT-P-32B in the near-IR and the visible. We clearly resolve the two stars from each other and find a separation of 2.''923 ± 0.''004 and a position angle 110fdg64 ± 0fdg12. We measure the flux ratios of the binary in g'r'i'z' and H and KS bands, and determine T eff= 3565 ± 82 K for the companion star, corresponding to an M1.5 dwarf. We use PHOENIX stellar atmosphere models to correct the dilution of the secondary eclipse depths of the hot Jupiter due to the presence of the M1.5 companion. We also improve the secondary eclipse photometry by accounting for the non-classical, flux-dependent nonlinearity of the WIRC IR detector in the H band. We measure planet-to-star flux ratios of 0.090% ± 0.033%, 0.178% ± 0.057%, 0.364% ± 0.016%, and 0.438% ± 0.020% in the H, KS , 3.6 and 4.5 μm bands, respectively. We compare these with planetary atmospheric models, and find they prefer an atmosphere with a temperature inversion and inefficient heat redistribution. However, we also find that the data are equally well described by a blackbody model for the planet with T p = 2042 ± 50 K. Finally, we measure a secondary eclipse timing offset of 0.3 ± 1.3 minutes from the predicted mid-eclipse time, which constrains e = 0.0072 +0.0700}_-0.0064 when combined with radialNASACenter for Exoplanets and Habitable Worlds at the Pennsylvania State UniversityPennsylvania State UniversityEberly College of SciencePennsylvania Space Grant ConsortiumNational Science Foundation - Graduate Research Fellowship ProgramNatural Science and Engineering Research Council of CanadaJPL/SpitzerCalifornia Institute of Technology - NASA Sagan FellowshipAlfred P. Sloan FoundationCalifornia Institute of TechnologyInter-University Centre for Astronomy and AstrophysicsNational Science FoundationMt. Cuba Astronomical FoundationSamuel Oschi
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