567 research outputs found

    ELECTROSTATIC BODY-MOTION REGISTRATION AND THE HUMAN ANTENNA-RECEIVER EFFECT: A NEW METHOD FOR INVESTIGATING INTERPERSONAL DYNAMICAL ENERGY SYSTEM INTERACTIONS

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    This paper documents that it is possible to measure electromagnetic fields created by physical movements of the human body-termed electrostatic body-motion effects-using readily available EEG amplifiers, and that it possible to measure the human body's capability to serve as an antenna and/or receiver for these electrostatic movements-termed the human antenna-receiver effect. Following the observation by Green et al (1991)1 that small body-motions could be detected by electrometers attached to copper walls, three experiments were conducted measuring the effects of hand-motions and foot-motions using DC amplifiers (the Synamps System by Neuroscan). Clear hand-motion and foot-motion effects could be recorded using a standard electrode box as an antenna. The electrostatic motion effect was attenuated as a function of distance of the motions from the electrode box, and by placing a wire mesh shield over the electrode box. The human body was discovered to funcrion as a strong antenna and/or receiver for electrostatic body-motions. The findings indicate that electrostatic body-motions and the human antenna-receiver effect are easily measurable, and may serve as a new method for investigating interpersonal dynamic energy system interactions in psychology, medicine and healing

    Entanglement of photons

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    It is argued that the title of this paper represents a misconception. Contrary to widespread beliefs it is electromagnetic field modes that are ``systems'' and can be entangled, not photons. The amount of entanglement in a given state is shown to depend on redefinitions of the modes; we calculate the minimum and maximum over all such redefinitions for several examples.Comment: 5 pages ReVTe

    Self-energy and Self-force in the Space-time of a Thick Cosmic String

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    We calculate the self-energy and self-force for an electrically charged particle at rest in the background of Gott-Hiscock cosmic string space-time. We found the general expression for the self-energy which is expressed in terms of the SS matrix of the scattering problem. The self-energy continuously falls down outward from the string's center with maximum at the origin of the string. The self-force is repulsive for an arbitrary position of the particle. It tends to zero in the string's center and also far from the string and it has a maximum value at the string's surface. The plots of the numerical calculations of the self-energy and self-force are shown.Comment: 15 pages, 4 Postscript figures, ReVTe

    Decoupling of the S=1/2 antiferromagnetic zig-zag ladder with anisotropy

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    The spin-1/2 antiferromagnetic zig-zag ladder is studied by exact diagonalization of small systems in the regime of weak inter-chain coupling. A gapless phase with quasi long-range spiral correlations has been predicted to occur in this regime if easy-plane (XY) anisotropy is present. We find in general that the finite zig-zag ladder shows three phases: a gapless collinear phase, a dimer phase and a spiral phase. We study the level crossings of the spectrum,the dimer correlation function, the structure factor and the spin stiffness within these phases, as well as at the transition points. As the inter-chain coupling decreases we observe a transition in the anisotropic XY case from a phase with a gap to a gapless phase that is best described by two decoupled antiferromagnetic chains. The isotropic and the anisotropic XY cases are found to be qualitatively the same, however, in the regime of weak inter-chain coupling for the small systems studied here. We attribute this to a finite-size effect in the isotropic zig-zag case that results from exponentially diverging antiferromagnetic correlations in the weak-coupling limit.Comment: to appear in Physical Review

    Fast Diffusion Process in Quenched hcp Dilute Solid 3^3He-4^4He Mixture

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    The study of phase structure of dilute 3^3He - 4^4He solid mixture of different quality is performed by spin echo NMR technique. The diffusion coefficient is determined for each coexistent phase. Two diffusion processes are observed in rapidly quenched (non-equilibrium) hcp samples: the first process has a diffusion coefficient corresponding to hcp phase, the second one has huge diffusion coefficient corresponding to liquid phase. That is evidence of liquid-like inclusions formation during fast crystal growing. It is established that these inclusions disappear in equilibrium crystals after careful annealing.Comment: 7 pages, 3 figures, QFS200

    Analytical approximation of the stress-energy tensor of a quantized scalar field in static spherically symmetric spacetimes

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    Analytical approximations for {} and {} of a quantized scalar field in static spherically symmetric spacetimes are obtained. The field is assumed to be both massive and massless, with an arbitrary coupling Îľ\xi to the scalar curvature, and in a zero temperature vacuum state. The expressions for {} and {} are divided into low- and high-frequency parts. The contributions of the high-frequency modes to these quantities are calculated for an arbitrary quantum state. As an example, the low-frequency contributions to {} and {} are calculated in asymptotically flat spacetimes in a quantum state corresponding to the Minkowski vacuum (Boulware quantum state). The limits of the applicability of these approximations are discussed.Comment: revtex4, 17 pages; v2: three references adde

    Electromagnetic Casimir densities induced by a conducting cylindrical shell in the cosmic string spacetime

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    We investigate the renormalized vacuum expectation values of the field square and the energy-momentum tensor for the electromagnetic field inside and outside of a conducting cylindrical shell in the cosmic string spacetime. By using the generalized Abel-Plana formula, the vacuum expectation values are presented in the form of the sum of boundary-free and boundary-induced parts. The asymptotic behavior of the vacuum expectation values of the field square, energy density and stresses are investigated in various limiting cases.Comment: 14 pages, 2 figures, discussion and references added, accepted for publication in Phys. Lett.

    Faraday rotation spectra of bismuth-substituted ferrite garnet films with in-plane magnetization

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    Single crystalline films of bismuth-substituted ferrite garnets have been synthesized by the liquid phase epitaxy method where GGG substrates are dipped into the flux. The growth parameters are controlled to obtain films with in-plane magnetization and virtually no domain activity, which makes them excellently suited for magnetooptic imaging. The Faraday rotation spectra were measured across the visible range of wavelengths. To interprete the spectra we present a simple model based on the existence of two optical transitions of diamagnetic character, one tetrahedral and one octahedral. We find excellent agreement between the model and our experimental results for photon energies between 1.77 and 2.53 eV, corresponding to wavelengths between 700 and 490 nm. It is shown that the Faraday rotation changes significantly with the amount of substituted gallium and bismuth. Furthermore, the experimental results suggest that the magnetooptic response changes linearly with the bismuth substitution.Comment: 15 pages, 6 figures, published in Phys. Rev.

    Plankton lattices and the role of chaos in plankton patchiness

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    Spatiotemporal and interspecies irregularities in planktonic populations have been widely observed. Much research into the drivers of such plankton patches has been initiated over the past few decades but only recently have the dynamics of the interacting patches themselves been considered. We take a coupled lattice approach to model continuous-in-time plankton patch dynamics, as opposed to the more common continuum type reaction-diffusion-advection model, because it potentially offers a broader scope of application and numerical study with relative ease. We show that nonsynchronous plankton patch dynamics (the discrete analog of spatiotemporal irregularity) arise quite naturally for patches whose underlying dynamics are chaotic. However, we also observe that for parameters in a neighborhood of the chaotic regime, smooth generalized synchronization of nonidentical patches is more readily supported which reduces the incidence of distinct patchiness. We demonstrate that simply associating the coupling strength with measurements of (effective) turbulent diffusivity results in a realistic critical length of the order of 100 km, above which one would expect to observe unsynchronized behavior. It is likely that this estimate of critical length may be reduced by a more exact interpretation of coupling in turbulent flows

    Method to compute the stress-energy tensor for the massless spin 1/2 field in a general static spherically symmetric spacetime

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    A method for computing the stress-energy tensor for the quantized, massless, spin 1/2 field in a general static spherically symmetric spacetime is presented. The field can be in a zero temperature state or a non-zero temperature thermal state. An expression for the full renormalized stress-energy tensor is derived. It consists of a sum of two tensors both of which are conserved. One tensor is written in terms of the modes of the quantized field and has zero trace. In most cases it must be computed numerically. The other tensor does not explicitly depend on the modes and has a trace equal to the trace anomaly. It can be used as an analytic approximation for the stress-energy tensor and is equivalent to other approximations that have been made for the stress-energy tensor of the massless spin 1/2 field in static spherically symmetric spacetimes.Comment: 34 pages, no figure
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