74,085 research outputs found

    BRST invariance and de Rham-type cohomology of 't Hooft-Polyakov monopole

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    We exploit the 't Hooft-Polyakov monopole to define closed algebra of the quantum field operators and the BRST charge QBRSTQ_{BRST}. In the first-class configuration of the Dirac quantization, by including the QBRSTQ_{BRST}-exact gauge fixing term and the Faddeev-Popov ghost term, we find the BRST invariant Hamiltonian to investigate the de Rham-type cohomology group structure for the monopole system. The Bogomol'nyi bound is also discussed in terms of the first-class topological charge defined on the extended internal 2-sphere.Comment: 8 page

    Scientific publications of the bioscience programs division. Volume 5 - Planetary quarantine

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    Bibliography and indexes on planetary quarantin

    A Tri-band-notched UWB Antenna with Low Mutual Coupling between the Band-notched Structures

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    A compact printed U-shape ultra-wideband (UWB) antenna with triple band-notched characteristics is presented. The proposed antenna, with compact size of 24×33 mm2, yields an impedance bandwidth of 2.8-12GHz for VSWR<2, except the notched bands. The notched bands are realized by introducing two different types of slots. Two C-shape half-wavelength slots are etched on the radiating patch to obtain two notched bands in 3.3-3.7GHz for WiMAX and 7.25-7.75GHz for downlink of X-band satellite communication systems. In order to minimize the mutual coupling between the band-notched structures, the middle notched band in 5-6GHz for WLAN is achieved by using a U-slot defected ground structure. The parametric study is carried out to understand the mutual coupling. Surface current distributions and equivalent circuit are used to illustrate the notched mechanism. The performance of this antenna both by simulation and by experiment indicates that the proposed antenna is suitable and a good candidate for UWB applications

    Asymptotic behavior of the least common multiple of consecutive arithmetic progression terms

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    Let ll and mm be two integers with l>m0l>m\ge 0, and let aa and bb be integers with a1a\ge 1 and a+b1a+b\ge 1. In this paper, we prove that loglcmmn<iln{ai+b}=An+o(n)\log {\rm lcm}_{mn<i\le ln}\{ai+b\} =An+o(n), where AA is a constant depending on l,ml, m and aa.Comment: 8 pages. To appear in Archiv der Mathemati

    Application of large eddy interaction model to channel flow

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    A procedure utilizing an expansion of proper orthogonal functions (or modes) to predict a fully developed flow in channel is derived. To examine numerical and conceptual difficulties, preliminary computations are performed with assigned mean velocity, and turbulence is expressed with only the first mode. The nonlinear interactions of the components of the first mode are treated specifically, with the influence of higher modes neglected; this treatment required adjustment of the skewness and effective Reynolds number to assure energy equilibrium of the first mode. Computational results show that the first mode possesses the structural character similar to that of the entire flow

    The Contribution of Hot Electron Spin Polarization to the Magnetotransport in a Spin-Valve Transistor at Finite Temperatures

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    The effect of spin mixing due to thermal spin waves and temperature dependence of hot electron spin polarization to the collector current in a spin-valve transistor has been theoretically explored. We calculate the collector current as well as the temperature dependence of magnetocurrent at finite temperatures to investigate the relative importance of spin mixing and hot electron spin polarization. In this study the inelastic scattering events in ferromagnetic layers have been taken into account to explore our interests. The theoretical calculations suggest that the temperature dependence of hot electron spin polarization has substantial contribution to the magnetotransport in the spin-valve transistor.Comment: 8 pages and 6 figure

    Flavor symmetry breaking effects on SU(3) Skyrmion

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    We study the massive SU(3) Skyrmion model to investigate the flavor symmetry breaking (FSB) effects on the static properties of the strange baryons in the framework of the rigid rotator quantization scheme combined with the improved Dirac quantization one. Both the chiral symmetry breaking pion mass and FSB kinetic terms are shown to improve cc the ratio of the strange-light to light-light interaction strengths and cˉ\bar{c} that of the strange-strange to light-light.Comment: 12 pages, latex, no figure

    Straight-line Drawability of a Planar Graph Plus an Edge

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    We investigate straight-line drawings of topological graphs that consist of a planar graph plus one edge, also called almost-planar graphs. We present a characterization of such graphs that admit a straight-line drawing. The characterization enables a linear-time testing algorithm to determine whether an almost-planar graph admits a straight-line drawing, and a linear-time drawing algorithm that constructs such a drawing, if it exists. We also show that some almost-planar graphs require exponential area for a straight-line drawing

    The least common multiple of a sequence of products of linear polynomials

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    Let f(x)f(x) be the product of several linear polynomials with integer coefficients. In this paper, we obtain the estimate: loglcm(f(1),...,f(n))An\log {\rm lcm}(f(1), ..., f(n))\sim An as nn\rightarrow\infty , where AA is a constant depending on ff.Comment: To appear in Acta Mathematica Hungaric
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