4,843 research outputs found

    Aspects of Confinement and Chiral Dynamics in 2-d QED at Finite Temperature

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    We evaluate the Polyakov loop and string tension at zero and finite temperature in QED2.QED_2. Using bozonization the problem is reduced to solving the Schr\"odinger equation with a particular potential determined by the ground state. In the presence of two sources of opposite charges the vacuum angle parameter θ\theta changes by 2π(q/e)2\pi (q/e), independent of the number of flavors. This, in turn, alters the chiral condensate. Particularly, in the one flavor case through a simple computer algorithm, we explore the chiral dynamics of a heavy fermion.Comment: 4 pages, 2 ps files, uses sprocl.sty. To appear in Proceedings of DPF96 (August, Minnesota

    Confinement and Chiral Dynamics in the Multi-flavor Schwinger Model

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    Two-dimensional QED with NN flavor fermions is solved at zero and finite temperature with arbitrary fermion masses to explore QCD physics such as chiral condensate and string tension. The problem is reduced to solving a Schr\"odinger equation for NN degrees of freedom with a specific potential determined by the ground state of the Schr\"odinger problem itself.Comment: 9 pages. 3 ps files and sprocl.sty attached. To appear in the Proceedings of the QCD 96 workshop (March, Minnesota

    Improving the communication with stakeholders: the infrastructure degradation index and the infrastructure histogram

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    [EN] Water infrastructures are rapidly ageing without being properly replaced. Communicating the state of the network and the sector¿s needs to stakeholders is key for guaranteeing the sustainability of water and sewage systems. The infrastructure value index (IVI) is becoming a standard in the water industry as a communication tool; however, as a single value metric, it can mask key information. The complementary use of the infrastructure degradation index (IDI) and the infrastructure histogram (Hi) can provide a better understanding of the network's state while maintaining the simplicity of the analysis needed for public dissemination. The IVI is focused on the value of the infrastructure, the IDI on its median remaining life. The HI provides a detailed but simple picture of the network's remaining life, providing a clear idea of the magnitude of the investments needed in the future for maintaining the infrastructureEstruch-Juan, ME.; Cabrera Rochera, E.; Gomez Selles, E.; Del Teso-March, R. (2020). Improving the communication with stakeholders: the infrastructure degradation index and the infrastructure histogram. Water Science & Technology: Water Supply. 20(7):2762-2767. https://doi.org/10.2166/ws.2020.170S2762276720

    Anomalies, Horizons and Hawking radiation

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    Hawking radiation is obtained from the Reissner-Nordstr\"{o}m blackhole with a global monopole and the Garfinkle-Horowitz-Strominger blackhole falling in the class of the most general spherically symmetric blackholes (g1)(\sqrt{-g}\neq1), using only chiral anomaly near the event horizon and covariant boundary condition at the event horizon. The approach differs from the anomaly cancellation approach since apart from the covariant boundary condition, the chiral anomaly near the horizon is the only input to derive the Hawking flux.Comment: minor corrections made, To appear in Euro. Phys. Letter

    Hawking Radiation from Charged Black Holes via Gauge and Gravitational Anomalies

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    Extending gr-qc/0502074, we show that in order to avoid a breakdown of general covariance and gauge invariance at the quantum level the total flux of charge and energy in each outgoing partial wave of a charged quantum field in a Reissner-Nordstrom black hole background must be equal to that of a (1+1) dimensional blackbody at the Hawking temperature with the appropriate chemical potential.Comment: 4 pages, typos corrected, references added, version to appear in Phys. Rev. Let

    Standardisation of magnetic nanoparticles in liquid suspension

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    Suspensions of magnetic nanoparticles offer diverse opportunities for technology innovation, spanning a large number of industry sectors from imaging and actuation based applications in biomedicine and biotechnology, through large-scale environmental remediation uses such as water purification, to engineering-based applications such as position-controlled lubricants and soaps. Continuous advances in their manufacture have produced an ever-growing range of products, each with their own unique properties. At the same time, the characterisation of magnetic nanoparticles is often complex, and expert knowledge is needed to correctly interpret the measurement data. In many cases, the stringent requirements of the end-user technologies dictate that magnetic nanoparticle products should be clearly defined, well characterised, consistent and safe; or to put it another way—standardised. The aims of this document are to outline the concepts and terminology necessary for discussion of magnetic nanoparticles, to examine the current state-of-the-art in characterisation methods necessary for the most prominent applications of magnetic nanoparticle suspensions, to suggest a possible structure for the future development of standardisation within the field, and to identify areas and topics which deserve to be the focus of future work items. We discuss potential roadmaps for the future standardisation of this developing industry, and the likely challenges to be encountered along the way

    Chern-Simons matrix model: coherent states and relation to Laughlin wavefunctions

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    Using a coherent state representation we derive many-body probability distributions and wavefunctions for the Chern-Simons matrix model proposed by Polychronakos and compare them to the Laughlin ones. We analyze two different coherent state representations, corresponding to different choices for electron coordinate bases. In both cases we find that the resulting probability distributions do not quite agree with the Laughlin ones. There is agreement on the long distance behavior, but the short distance behavior is different.Comment: 15 pages, LaTeX; one reference added, abstract and section 5 expanded, typos correcte

    Back reaction, covariant anomaly and effective action

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    In the presence of back reaction, we first produce the one-loop corrections for the event horizon and Hawking temperature of the Reissner-Nordstr\"om black hole. Then, based on the covariant anomaly cancelation method and the effective action technique, the modified expressions for the fluxes of gauge current and energy momentum tensor, due to the effect of back reaction, are obtained. The results are consistent with the Hawking fluxes of a (1+1)-dimensional blackbody at the temperature with quantum corrections, thus confirming the robustness of the covariant anomaly cancelation method and the effective action technique for black holes with back reaction.Comment: 17 page

    Microscopic Theory of Skyrmions in Quantum Hall Ferromagnets

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    We present a microscopic theory of skyrmions in the monolayer quantum Hall ferromagnet. It is a peculiar feature of the system that the number density and the spin density are entangled intrinsically as dictated by the W%_{\infty} algebra. The skyrmion and antiskyrmion states are constructed as W_{\infty }-rotated states of the hole-excited and electron-excited states, respectively. They are spin textures accompanied with density modulation that decreases the Coulomb energy. We calculate their excitation energy as a function of the Zeeman gap and compared the result with experimental data.Comment: 15 pages (to be published in PRB

    Hawking Fluxes, Back reaction and Covariant Anomalies

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    Starting from the chiral covariant effective action approach of Banerjee and Kulkarni [Phys. Lett. B 659, 827(2008)], we provide a derivation of the Hawking radiation from a charged black hole in the presence of gravitational back reaction. The modified expressions for charge and energy flux, due to effect of one loop back reaction are obtained.Comment: 6 pages, no figures, minor changes and references added, to appear in Classical and Quantum Gravit
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