2,443 research outputs found

    Design and development of a fast scan infrared detection and measurement instrument

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    Infrared microscope instrument measures and plots the infrared profile of semiconductor chips, transistors and integrated circuits. Infrared analyses yields information on electrical and physical properties, enabling manufacturing improvements in semiconductor performance and reliability. Operational performance and main sections of the instrument are given

    The Consistent Newtonian Limit of Einstein's Gravity with a Cosmological Constant

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    We derive the `exact' Newtonian limit of general relativity with a positive cosmological constant Λ\Lambda. We point out that in contrast to the case with Λ=0\Lambda = 0 , the presence of a positive Λ\Lambda in Einsteins's equations enforces, via the condition Φ1| \Phi | \ll 1, on the potential Φ\Phi, a range Rmax(Λ)rRmin(Λ){\cal R}_{max}(\Lambda) \gg r \gg {\cal R}_{min} (\Lambda), within which the Newtonian limit is valid. It also leads to the existence of a maximum mass, Mmax(Λ){\cal M}_{max}(\Lambda). As a consequence we cannot put the boundary condition for the solution of the Poisson equation at infinity. A boundary condition suitably chosen now at a finite range will then get reflected in the solution of Φ\Phi provided the mass distribution is not spherically symmetric.Comment: Latex, 15 pages, no figures, errors correcte

    Quantum Mechanical Corrections to the Schwarzschild Black Hole Metric

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    Motivated by quantum mechanical corrections to the Newtonian potential, which can be translated into an \hbar-correction to the g00g_{00} component of the Schwarzschild metric, we construct a quantum mechanically corrected metric assuming g00=grr-g_{00}=g^{rr}. We show how the Bekenstein black hole entropy SS receives its logarithmic contribution provided the quantum mechanical corrections to the metric are negative. In this case the standard horizon at the Schwarzschild radius rSr_S increases by small terms proportional to \hbar and a remnant of the order of Planck mass emerges. We contrast these results with a positive correction to the metric which, apart from a corrected Schwarzschild horizon, leads to a new purely quantum mechanical horizon.Comment: 14 pages Latex, enlarged version as compared to the published on

    Efficient bounds on quantum communication rates via their reduced variants

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    We investigate one-way communication scenarios where Bob manipulating on his parts can transfer some sub-system to the environment. We define reduced versions of quantum communication rates and further, prove new upper bounds on one-way quantum secret key, distillable entanglement and quantum channel capacity by means of their reduced versions. It is shown that in some cases they drastically improve their estimation.Comment: 6 pages, RevTe

    Dispersion relations and wave operators in self-similar quasicontinuous linear chains

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    We construct self-similar functions and linear operators to deduce a self-similar variant of the Laplacian operator and of the D'Alembertian wave operator. The exigence of self-similarity as a symmetry property requires the introduction of nonlocal particle-particle interactions. We derive a self-similar linear wave operator describing the dynamics of a quasicontinuous linear chain of infinite length with a spatially self-similar distribution of nonlocal interparticle springs. The self-similarity of the nonlocal harmonic particle-particle interactions results in a dispersion relation of the form of a Weierstrass-Mandelbrot function that exhibits self-similar and fractal features. We also derive a continuum approximation, which relates the self-similar Laplacian to fractional integrals, and yields in the low-frequency regime a power-law frequency-dependence of the oscillator density

    γγ\gamma \gamma Processes at High Energy pp Colliders

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    In this note we investigate the production of charged heavy particles via \gaga\ fusion at high energy pp colliders. We revise previous claims that the \gaga\ cross section is comparable to or larger than that for the corresponding Drell-Yan process at high energies. Indeed we find that the \gaga\ contribution to the total production cross section at pp is far below the Drell-Yan cross section. As far as the individual elastic, semi-elastic and inelastic contributions to the \gaga\ process are concerned we find that they are all of the same order of magnitude.Comment: REVTEX, 12 pages, two uuencoded figures appended at the end of the fil

    About the propagation of the Gravitational Waves in an asymptotically de-Sitter space: Comparing two points of view

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    We analyze the propagation of gravitational waves (GWs) in an asymptotically de-Sitter space by expanding the perturbation around Minkowski and introducing the effects of the Cosmological Constant (Λ\Lambda), first as an additional source (de-Donder gauge) and after as a gauge effect (Λ\Lambda-gauge). In both cases the inclusion of the Cosmological Constant Λ\Lambda impedes the detection of a gravitational wave at a distance larger than Lcrit=(62πfh^/5)rΛ2L_{crit}=(6\sqrt{2}\pi f \hat{h}/\sqrt{5})r_\Lambda^2, where rΛ=1Λr_\Lambda=\frac{1}{\sqrt{\Lambda}} and f and h^\hat{h} are the frequency and strain of the wave respectively. We demonstrate that LcritL_{crit} is just a confirmation of the Cosmic No hair Conjecture (CNC) already explained in the literature.Comment: Accepted for publication in MPL

    Data management procedures for Tiepoint Registration, pre and post processing, and ICD116

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    The data management procedures for tiepoint registration, pre and post processing, and "ICD116' are described. With each procedure description, the pertinent execs are listed and purposes defined. An example run of each of the 32 execs is included with user inputs identified

    Gravitational Equilibrium in the Presence of a Positive Cosmological Constant

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    We reconsider the virial theorem in the presence of a positive cosmological constant Lambda. Assuming steady state, we derive an inequality of the form rho >= A (Lambda / 4 pi GN) for the mean density rho of the astrophysical object. With a minimum at Asphere = 2, its value can increase by several orders of magnitude as the shape of the object deviates from a spherically symmetric one. This, among others, indicates that flattened matter distributions like e.g. clusters or superclusters, with low density, cannot be in gravitational equilibrium.Comment: 7 pages, no figure
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