544 research outputs found

    A privacy preserved and credible network protocol

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    This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordThe identities of packet senders and receivers are treated as important privacy information in communication networks. Any packet can be attributed to its sender for evaluating its credibility. Existing studies mainly rely on third-party agents that contain the packet sender's identity to ensure the sender's privacy preservation and credibility. In this case, packet senders run the risk that their privacy might be leaked by the agent. To this end, this paper proposes a Privacy Preserved and Credible Network Protocol (PCNP), which authorizes the agent to hide the identities of senders and receivers, while guaranteeing the credibility of a packet. The feasibility of the PCNP deployment is analyzed, and its performance is evaluated through extensive experiments.Ministry of Science and Technology of ChinaChinese Academy of Scienc

    Exact Renormalization of Massless QED2

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    We perform the exact renormalization of two-dimensional massless gauge theories. Using these exact results we discuss the cluster property and confinement in both the anomalous and chiral Schwinger models.Comment: 14 pages, no figures, introduction and conclusions modifie

    On the Renormalizability of Theories with Gauge Anomalies

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    We consider the detailed renormalization of two (1+1)-dimensional gauge theories which are quantized without preserving gauge invariance: the chiral and the "anomalous" Schwinger models. By regularizing the non-perturbative divergences that appear in fermionic Green's functions of both models, we show that the "tree level" photon propagator is ill-defined, thus forcing one to use the complete photon propagator in the loop expansion of these functions. We perform the renormalization of these divergences in both models to one loop level, defining it in a consistent and semi-perturbative sense that we propose in this paper.Comment: Final version, new title and abstract, introduction and conclusion rewritten, detailed semiperturbative discussion included, references added; to appear in International Journal of Modern Physics

    Photoluminescence study of C-60 doped polystyrene

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    We report here a new phenomenon in photoluminescence of C-60 doped in polystyrene. Under 488 nm cw laser radiation, the PL intensity of the sample was found to increase with time. With 10 h of irradiation, the PL signal strength increased by 10 times, comparable to that from porous Si. The peak of the PL was found to shift to high frequency as well. More detailed studies showed that such an irreversible change of the sample might be a result of the lowering symmetry of oxidized C-60 fullerene in the polystyrene. (C) 1996 American Institute of Physics

    A simple proof of Perelman's collapsing theorem for 3-manifolds

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    We will simplify earlier proofs of Perelman's collapsing theorem for 3-manifolds given by Shioya-Yamaguchi and Morgan-Tian. Among other things, we use Perelman's critical point theory (e.g., multiple conic singularity theory and his fibration theory) for Alexandrov spaces to construct the desired local Seifert fibration structure on collapsed 3-manifolds. The verification of Perelman's collapsing theorem is the last step of Perelman's proof of Thurston's Geometrization Conjecture on the classification of 3-manifolds. Our proof of Perelman's collapsing theorem is almost self-contained, accessible to non-experts and advanced graduate students. Perelman's collapsing theorem for 3-manifolds can be viewed as an extension of implicit function theoremComment: v1: 9 Figures. In this version, we improve the exposition of our arguments in the earlier arXiv version. v2: added one more grap

    Observation of eight-photon entanglement

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    Using ultra-bright sources of pure-state entangled photons from parametric down conversion, an eight-photon interferometer and post-selection detection, we demonstrate the ability to experimentally manipulate eight individual photons and report the creation of an eight-photon Schr\"odinger cat state with an observed fidelity of 0.708±0.0160.708 \pm 0.016.Comment: 6 pages, 4 figure

    Quantum teleportation and entanglement distribution over 100-kilometre free-space channels

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    A long standing goal for quantum communication is to transfer a quantum state over arbitrary distances. Free-space quantum communication provides a promising solution towards this challenging goal. Here, through a 97-km free space channel, we demonstrate long distance quantum teleportation over a 35-53 dB loss one-link channel, and entanglement distribution over a 66-85 dB high-loss two-link channel. We achieve an average fidelity of {80.4(9)}% for teleporting six distinct initial states and observe the violation of the Clauser-Horne-Shimony-Holt inequality after distributing entanglement. Besides being of fundamental interest, our result represents a significant step towards a global quantum network. Moreover, the high-frequency and high-accuracy acquiring, pointing and tracking technique developed in our experiment provides an essential tool for future satellite-based quantum communication.Comment: 9 pages, 8 figure

    Evidence for the Decay D0→K+π−π+π−D^0\to K^+ \pi^-\pi^+\pi^-

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    We present a search for the ``wrong-sign'' decay D0 -> K+ pi- pi+ pi- using 9 fb-1 of e+e- collisions on and just below the Upsilon(4S) resonance. This decay can occur either through a doubly Cabibbo-suppressed process or through mixing to a D0bar followed by a Cabibbo-favored process. Our result for the time-integrated wrong-sign rate relative to the decay D0 -> K- pi+ pi- pi+ is (0.0041 +0.0012-0.0011(stat.) +-0.0004(syst.))x(1.07 +-0.10)(phase space), which has a statistical significance of 3.9 standard deviations.Comment: 9 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, submitted to PR
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