13,727 research outputs found

    Dual Actions for Born-Infeld and Dp-Brane Theories

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    Dual actions with respect to U(1) gauge fields for Born-Infeld and DpDp-brane theories are reexamined. Taking into account an additional condition, i.e. a corollary to the field equation of the auxiliary metric, one obtains an alternative dual action that does not involve the infinite power series in the auxiliary metric given by ref. \cite{s14}, but just picks out the first term from the series formally. New effective interactions of the theories are revealed. That is, the new dual action gives rise to an effective interaction in terms of one interaction term rather than infinite terms of different (higher) orders of interactions physically. However, the price paid for eliminating the infinite power series is that the new action is not quadratic but highly nonlinear in the Hodge dual of a (p−1)(p-1)-form field strength. This non-linearity is inevitable to the requirement the two dual actions are equivalent.Comment: v1: 11 pages, no figures; v2: explanation of effective interactions added; v3: concision made; v4: minor modification mad

    Critical points of Wang-Yau quasi-local energy

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    In this paper, we prove the following theorem regarding the Wang-Yau quasi-local energy of a spacelike two-surface in a spacetime: Let Σ\Sigma be a boundary component of some compact, time-symmetric, spacelike hypersurface Ω\Omega in a time-oriented spacetime NN satisfying the dominant energy condition. Suppose the induced metric on Σ\Sigma has positive Gaussian curvature and all boundary components of Ω\Omega have positive mean curvature. Suppose H≤H0H \le H_0 where HH is the mean curvature of Σ\Sigma in Ω\Omega and H0H_0 is the mean curvature of Σ\Sigma when isometrically embedded in R3R^3. If Ω\Omega is not isometric to a domain in R3R^3, then 1. the Brown-York mass of Σ\Sigma in Ω\Omega is a strict local minimum of the Wang-Yau quasi-local energy of Σ\Sigma, 2. on a small perturbation Σ~\tilde{\Sigma} of Σ\Sigma in NN, there exists a critical point of the Wang-Yau quasi-local energy of Σ~\tilde{\Sigma}.Comment: substantially revised, main theorem replaced, Section 3 adde

    Duality Symmetry in Momentum Frame

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    Siegel's action is generalized to the D=2(p+1) (p even) dimensional space-time. The investigation of self-duality of chiral p-forms is extended to the momentum frame, using Siegel's action of chiral bosons in two space-time dimensions and its generalization in higher dimensions as examples. The whole procedure of investigation is realized in the momentum space which relates to the configuration space through the Fourier transformation of fields. These actions correspond to non-local Lagrangians in the momentum frame. The self-duality of them with respect to dualization of chiral fields is uncovered. The relationship between two self-dual tensors in momentum space, whose similar form appears in configuration space, plays an important role in the calculation, that is, its application realizes solving algebraically an integral equation.Comment: 11 pages, no figures, to appear in Phys. Rev.

    Orbital Characters Determined from Fermi Surface Intensity Patterns using Angle-Resolved Photoemission Spectroscopy

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    In order to determine the orbital characters on the various Fermi surface pockets of the Fe-based superconductors Ba0.6_{0.6}K0.4_{0.4}Fe2_{2}As2_{2} and FeSe0.45_{0.45}Te0.55_{0.55}, we introduce a method to calculate photoemission matrix elements. We compare our simulations to experimental data obtained with various experimental configurations of beam orientation and light polarization. We show that the photoemission intensity patterns revealed from angle-resolved photoemission spectroscopy measurements of Fermi surface mappings and energy-momentum plots along high-symmetry lines exhibit asymmetries carrying precious information on the nature of the states probed, information that is destroyed after the data symmetrization process often performed in the analysis of angle-resolved photoemission spectroscopy data. Our simulations are consistent with Fermi surfaces originating mainly from the dxyd_{xy}, dxzd_{xz} and dyzd_{yz} orbitals in these materials.Comment: 16 pages, 9 figures. Figures modified, typos corrected, appendix adde

    Massive charged particle's tunneling from spherical charged black hole

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    We generalize the Parikh-Wilczek scheme to the tunneling of a massive charged particle from a general spherical charged black hole. We obtain that the tunneling probability depends on the energy, the mass and the charge of the particle. In particular, the modified Hawking temperature is related to the charge. Only at the leading order approximation can the standard Hawking temperature be reproduced. We take the Reissner-Nordstr\"{o}m black hole as an example to clarify our points of view, and find that the accumulation of Hawking radiation makes it approach an extreme black hole.Comment: 10 pages, no figures; v2: a minor typo corrected; v3: 11 pages, clarification and reference added, final version to be published in EPL; v4: minor modifications to match the published versio
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