5,215 research outputs found

    Lifetime statistics of quantum chaos studied by a multiscale analysis

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    In a series of pump and probe experiments, we study the lifetime statistics of a quantum chaotic resonator when the number of open channels is greater than one. Our design embeds a stadium billiard into a two dimensional photonic crystal realized on a Silicon-on-insulator substrate. We calculate resonances through a multiscale procedure that combines graph theory, energy landscape analysis and wavelet transforms. Experimental data is found to follow the universal predictions arising from random matrix theory with an excellent level of agreement.Comment: 4 pages, 6 figure

    The bosonic Kondo effect

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    The Kondo effect is associated with the formation of a many-body ground state that contains a quantum-mechanical entanglement between a (localized) fermion and the free fermions. We show that a bosonic version of the Kondo effect can occur in degenerate atomic Fermi gases near the Feshbach resonance. We also discuss how this bosonic Kondo effect can be observed experimentally.Comment: 4 pages, 2 figures, some references added, some removed. More comments adde

    Analyticity of the SRB measure for a class of simple Anosov flows

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    We consider perturbations of the Hamiltonian flow associated with the geodesic flow on a surface of constant negative curvature. We prove that, under a small perturbation, not necessarely of Hamiltonian character, the SRB measure associated to the flow exists and is analytic in the strength of the perturbation. An explicit example of "thermostatted" dissipative dynamics is constructed.Comment: 23 pages, corrected typo

    Results from the CASTLES Survey of Gravitational Lenses

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    We show that most gravitational lenses lie on the passively evolving fundamental plane for early-type galaxies. For burst star formation models (1 Gyr of star formation, then quiescence) in low Omega_0 cosmologies, the stellar populations of the lens galaxies must have formed at z_f > 2. Typical lens galaxies contain modest amounts of patchy extinction, with a median differential extinction for the optical (radio) selected lenses of E(B-V) = 0.04 (0.07) mag. The dust can be used to determine both extinction laws and lens redshifts. For example, the z_l=0.96 elliptical lens in MG0414+0534 has an R_V=1.7 +/- 0.1 mean extinction law. Arc and ring images of the quasar and AGN source host galaxies are commonly seen in NICMOS H band observations. The hosts are typically blue, L < L_* galaxies.Comment: 12 pages, 10 figures, from Proceedings of the 9th Annual Astrophysics Conference in Maryland, After the Dark Ages: When Galaxies Were Youn

    Trade effects of geographical indication policy: The EU case

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    Using a new detailed dataset on country-product information on European Union (EU) Geographical Indications (GIs), we study the impact of this food quality policy on trade margins over the 1996–2014 period. We consider the effect of GIs on both intra- and extra-EU trade margins (extensive and intensive), as well as on export (and import) unit values. Our main results show that GIs affect trade flows differently depending on whether GIs are produced by the exporter or importer country. The presence of GIs in the exporter country systematically exerts a positive trade effect on both the extensive and intensive trade margin. When registered only in the importer country, GIs seem to act weakly as a trade-reducing measure, at least at the intensive trade margin. In addition, GIs positively affect export prices, consistent with the idea that GI products are perceived by consumers as higher quality goods. Importantly, extra-EU trade margins react similarly to those on intra-EU trade. These results have clear and interesting implications concerning the EU strategy of promoting the protection of GIs worldwide

    Speed and entropy of an interacting continuous time quantum walk

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    We present some dynamic and entropic considerations about the evolution of a continuous time quantum walk implementing the clock of an autonomous machine. On a simple model, we study in quite explicit terms the Lindblad evolution of the clocked subsystem, relating the evolution of its entropy to the spreading of the wave packet of the clock. We explore possible ways of reducing the generation of entropy in the clocked subsystem, as it amounts to a deficit in the probability of finding the target state of the computation. We are thus lead to examine the benefits of abandoning some classical prejudice about how a clocking mechanism should operate.Comment: 25 pages, 14 figure

    Finding Gravitational Lenses With X-rays

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    There are ∼1\sim 1, 0.1 and 0.01 gravitationally lensed X-ray sources per square degree with soft X-ray fluxes exceeding 10−15,10−1410^{-15}, 10^{-14} and 10−13ergs/scm−210^{-13} ergs/s cm^{-2} respectively. These sources will be detected serendipitously with the Chandra X-ray Observatory at a rate of 1--3 lenses per year of high resolution imaging. The low detection rate is due to the small area over which the HRC and ACIS cameras have the <1\farcs5 FWHM resolution necessary to find gravitational lenses produced by galaxies. Deep images of rich clusters at intermediate redshifts should yield one wide separation (\Delta\theta \gtorder 5\farcs0) multiply-imaged background X-ray source for every ∼10\sim 10, 30 and 300 clusters imaged to the same flux limits.Comment: 13 pages, including 5 figures, submitted to ApJ Letter
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