28,586 research outputs found

    Model of the polarized foreground diffuse Galactic emissions from 33 to 353 GHz

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    We present 3D models of the Galactic magnetic field including regular and turbulent components, and of the distribution of matter in the Galaxy including relativistic electrons and dust grains. By integrating along the line of sight, we construct maps of the polarized Galactic synchrotron and thermal dust emissions for each of these models. We perform a likelihood analysis to compare the maps of the Ka, Q, V and W bands of the Wilkinson Microwave Anisotropy Probe (Wmap) and the 353 GHz Archeops data to the models obtained by varying the pitch angle of the regular magnetic field, the relative amplitude of the turbulent magnetic field and the extrapolation spectral indices of the synchrotron and thermal dust emissions. The best-fit parameters obtained for the different frequency bands are very similar and globally the data seem to favor a negligible isotropic turbulent magnetic field component at large angular scales (an anisotropic line-of-sight ordered component can not be studied using these data). From this study, we conclude that we are able to propose a consistent model of the polarized diffuse Galac- tic synchrotron and thermal dust emissions in the frequency range from 33 to 353 GHz, where most of the CMB studies are performed and where we expect a mixture of these two main foreground emissions. This model can be very helpful to estimate the contamination by foregrounds of the polarized CMB anisotropies, for experiments like the Planck satellite.Comment: 22 pages, 4 figure

    A Relation Between the Kauffman and the HOMFLY Polynomials for Torus Knots

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    Polynomial invariants corresponding to the fundamental representation of the gauge group SO(N)SO(N) are computed for arbitrary torus knots in the framework of Chern-Simons gauge theory making use of knot operators. As a result, a formula which relates the Kauffman and the HOMFLY polynomials for torus knots is presented.Comment: 47 pages, macropackage phyzzx.tex, minor corrections made, version to appear in Journal of Mathematical Physic

    The use of permanent contracts across Spanish regions: Do regional wage subsidies work?

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    This article evaluates the effectiveness of regional wage subsidies to foster permanent employment using information gathered from the “Muestra Continua de Vidas Laborales”. This dataset, which is used here for the first time as a source for evaluating Spanish labour market policy, offers a complete employment history for each individual, with no aggregation bias. The policy analyzed consists of a one-time subsidy offered by some Spanish regions for new permanent contracts signed for certain fixed-term employees and unemployed workers. Because our policy variable presents individual, regional and temporal variation, we apply a triple difference estimator to identify the average treatment effect of this policy. We conclude that the outflow into permanent employment of eligible workers improves only minimally under this policy. Nevertheless, the incidence is relatively greater for temporary workers than for unemployed ones and is also larger for younger and middle-aged female workers.Difference-in-difference-in-difference, Causal Evaluation Analysis, Regional Wage Subsidies

    Coherent caloritronics in Josephson-based nanocircuits

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    We describe here the first experimental realization of a heat interferometer, thermal counterpart of the well-known superconducting quantum interference device (SQUID). These findings demonstrate, on the first place, the existence of phase-dependent heat transport in Josephson-based superconducting circuits and, on the second place, open the way to novel ways of mastering heat at the nanoscale. Combining the use of external magnetic fields for phase biasing and different Josephson junction architectures we show here that a number of heat interference patterns can be obtained. The experimental realization of these architectures, besides being relevant from a fundamental physics point of view, might find important technological application as building blocks of phase-coherent quantum thermal circuits. In particular, the performance of two different heat rectifying devices is analyzed.Comment: 34 pages, 15 figures, review article for Ultra-low temperatures and nanophysics ULTN2013. Microkelvin Proceeding
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