2,966 research outputs found

    The Role of a Changing Market Environment for Credit Default Swap Pricing

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    This paper investigates the impact of a changing market environment on the pricing of CDS spreads written on debt from EURO STOXX 50 firms. A Panel Smooth Transition Regression reveals that parameter estimates of standard CDS fundamentals are time-varying depending on current values of a set of variables such as the ECB's systemic stress composite index, the Sentix index for current and future economic situation, and the VStoxx. These variables describe the market's transition between different regimes thereby reflecting the impact of substantial swings in agents' risk perception on CDS spreads. Overall, our results confirm the importance of nonlinearities in the pricing of risk derivatives during tranquil and turbulent times

    Translations and dynamics

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    We analyze the role played by local translational symmetry in the context of gauge theories of fundamental interactions. Translational connections and fields are introduced, with special attention being paid to their universal coupling to other variables, as well as to their contributions to field equations and to conserved quantities.Comment: 22 Revtex pages, no figures. Published version with minor correction

    The facilitatory effect of duloxetine combined with pelvic floor muscle training on the excitability of urethral sphincter motor neurons

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    INTRODUCTION AND HYPOTHESIS: Aim of this study was to investigate the excitability of sphincter motor neurons under the influence of pelvic floor muscle training (PFMT) and duloxetine. Due to their mechanisms of action, there might be a synergistic effect of duloxetine and PFMT in regard to the facilitation of spinal reflexes controlling urethral sphincter contractions and hence continence. METHODS: In ten healthy female subjects, clitoral electric stimulation (CES) and transcranial magnetic stimulation (TMS) were used to determine individual motor thresholds for external urethral sphincter (EUS) contractions before and after PFMT, duloxetine, and PFMT + duloxetine. RESULTS: PFMT and duloxetine alone significantly decreased the motor thresholds for EUS contractions during CES and TMS. However, the combined treatment reduced the motor threshold for EUS contractions significantly stronger compared to PFMT or duloxetine alone. CONCLUSIONS: The results are suggestive for a synergistic facilitatory effect of PFMT and duloxetine on sphincter motor neuron activation

    Dispersive Optical Interface Based on Nanofiber-Trapped Atoms

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    We dispersively interface an ensemble of one thousand atoms trapped in the evanescent field surrounding a tapered optical nanofiber. This method relies on the azimuthally-asymmetric coupling of the ensemble with the evanescent field of an off-resonant probe beam, transmitted through the nanofiber. The resulting birefringence and dispersion are significant; we observe a phase shift per atom of ∼\sim\,1\,mrad at a detuning of six times the natural linewidth, corresponding to an effective resonant optical density per atom of 0.027. Moreover, we utilize this strong dispersion to non-destructively determine the number of atoms.Comment: 4 pages, 4 figure

    Electromagnetically induced transparency in cold 85Rb atoms trapped in the ground hyperfine F = 2 state

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    We report electromagnetically induced transparency (EIT) in cold 85Rb atoms, trapped in the lower hyperfine level F = 2, of the ground state 52S1/2^{2}S_{1/2} (Tiwari V B \textit{et al} 2008 {\it Phys. Rev.} A {\bf 78} 063421). Two steady state Λ\Lambda-type systems of hyperfine energy levels are investigated using probe transitions into the levels F′^{\prime} = 2 and F′^{\prime} = 3 of the excited state 52P3/2^{2}P_{3/2} in the presence of coupling transitions F = 3 →\to F′^{\prime} = 2 and F = 3 →\to F′^{\prime} = 3, respectively. The effects of uncoupled magnetic sublevel transitions and coupling field's Rabi frequency on the EIT signal from these systems are studied using a simple theoretical model.Comment: 12 pages, 7 figure

    Optical interface created by laser-cooled atoms trapped in the evanescent field surrounding an optical nanofiber

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    Trapping and optically interfacing laser-cooled neutral atoms is an essential requirement for their use in advanced quantum technologies. Here we simultaneously realize both of these tasks with cesium atoms interacting with a multi-color evanescent field surrounding an optical nanofiber. The atoms are localized in a one-dimensional optical lattice about 200 nm above the nanofiber surface and can be efficiently interrogated with a resonant light field sent through the nanofiber. Our technique opens the route towards the direct integration of laser-cooled atomic ensembles within fiber networks, an important prerequisite for large scale quantum communication schemes. Moreover, it is ideally suited to the realization of hybrid quantum systems that combine atoms with, e.g., solid state quantum devices

    Glimmerglass Volume 09 Number 12 (1950)

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    Official Student Newspaper Issue is 10 pages long

    Glimmerglass Volume 09 Number 09 (1950)

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    Official Student Newspaper Issue is 8 pages long

    Glimmerglass Volume 09 Number 07 (1950)

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    Official Student Newspaper Issue is 8 pages long
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