1,223 research outputs found

    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

    Dissipation Layers in Rayleigh-B\'{e}nard Convection: A Unifying View

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    Boundary layers play an important role in controlling convective heat transfer. Their nature varies considerably between different application areas characterized by different boundary conditions, which hampers a uniform treatment. Here, we argue that, independent from boundary conditions, systematic dissipation measurements in Rayleigh-B\'enard convection capture the relevant near-wall structures. By means of direct numerical simulations with varying Prandtl numbers, we demonstrate that such dissipation layers share central characteristics with classical boundary layers, but, in contrast to the latter, can be extended naturally to arbitrary boundary conditions. We validate our approach by explaining differences in scaling behavior observed for no-slip and stress-free boundaries, thus paving the way to an extension of scaling theories developed for laboratory convection to a broad class of natural systems

    Higher-Dimensional QCD without the Strong CP Problem

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    QCD in a five-dimensional sliced bulk with chiral extra-quarks on the boundaries is generically free from the strong CP problem. Accidental axial symmetry is naturally present except for suppressed breaking interactions, which plays a role of the Peccei-Quinn symmetry to make the strong CP phase sufficiently small.Comment: 7 pages, late

    Dissipation, noise and DCC domain formation

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    We investigate the effect of friction on domain formation in disoriented chiral condensate. We solve the equation of motion of the linear sigma model, in the Hartree approximation, including a friction and a white noise term. For quenched initial condition, we find that even in presence of noise and dissipation domain like structure emerges after a few fermi of evolution. Domain size as large as 5 fm can be formed.Comment: 7 pages, 3 figure

    Charge Violation and Alice Behavior in Global and Textured Strings

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    Spontaneous breaking of global symmetries can produce ``Alice'' strings: line defects which make unbroken symmetries multivalued, induce apparent charge violation via Aharonov-Bohm interactions, and form point defects when twisted into loops. We demonstrate this behavior for both divergent and textured global Alice strings. Both adiabatically scatter charged particles via effective Wilson lines. For textured Alice strings, such Wilson lines occur at all radii, and are multivalued only inside the string. This produces measurable effects, including path-dependent charge violation.Comment: 32 pages, 2 epsfigs, Revte

    Introduction to {\it Quantum Matter}

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    This paper records my opening remarks at Nobel Symposium 148, on Graphene and Quantum Matter, at Saltsj\"obaden, Sweden, in June 2010. After some broad comments on the quantum theory of matter as a frontier of physics, and some slightly more particular comments about re-quantization, I report on the universal geometry that arises in a refined discussion of quantum-mechanical level crossing.Comment: 12 pages, 1 table; Opening talk at at Nobel Symposium 148, on Graphene and Quantum Matter, at Saltsj\"obaden, Sweden, in June 2010, to be published in the Proceeedings (Physica Scripta). v. 2: Some garbling in equation 1 correcte

    Systematic Study Of Leptonic Mixing In A Class Of SU_H(2) Models

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    We perform a systematic analysis of the PMNS matrices which arise when one assigns the three generations of leptons to the 2⊕12\oplus 1 representation of a horizontal SUH(2)SU_H(2) symmetry. This idea has been previously explored by Kuchimanchi and Mohapatra. However, we assume (i)(i) the neutrino mass matrix results from leptonic couplings to SUL(2)SU_L(2) triplet scalar fields and (ii)(ii) hierarchies exist amongst lepton mass matrix elements which result from couplings to scalar fields with different SUH(2)SU_H(2) charges. Of the sixteen candidate PMNS matrices which result it is found that only one is both predictive and possesses a leading order structure compatible with experimental data. The relevant neutrino mass matrix displays the symmetry Le−Lμ−LτL_e-L_\mu-L_\tau to leading order and we explore the perturbations required to produce a realistic lepton spectrum. The effective mass in neutrinoless double beta decay is required to lie in the range /(10−2eV)∈[0.7,2.5]/(10^{-2}\mathrm{eV})\in[0.7,2.5], which is just below current experimental bounds. Ue3U_{e3} is non-zero but not uniquely determined.Comment: To appear in Phys. Rev.
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