34,533 research outputs found

    Massive uncharged and charged particles' tunneling from the Horowitz-Strominger Dilaton black hole

    Get PDF
    Originally, Parikh and Wilczek's work is only suitable for the massless particles' tunneling. But their work has been further extended to the cases of massive uncharged and charged particles' tunneling recently. In this paper, as a particular black hole solution, we apply this extended method to reconsider the tunneling effect of the H.S Dilaton black hole. We investigate the behavior of both massive uncharged and charged particles, and respectively calculate the emission rate at the event horizon. Our result shows that their emission rates are also consistent with the unitary theory. Moreover, comparing with the case of massless particles' tunneling, we find that this conclusion is independent of the kind of particles. And it is probably caused by the underlying relationship between this method and the laws of black hole thermodynamics.Comment: 6 pages, no figure, revtex 4, accepted by Int. J. Mod. Phys

    Coordinate shift in the semiclassical Boltzmann equation and the anomalous Hall effect

    Full text link
    We propose a gauge invariant expression for the side jump associated with scattering between particular Bloch states. Our expression for the side jump follows from the Born series expansion for the scattering T-matrix in powers of the strength of the scattering potential. Given our gauge invariant side jump expression, it is possible to construct a semiclassical Boltzmann theory of the anomalous Hall effect which expresses all previously identified contributions in terms of gauge invariant quantities and does not refer explicitly to off-diagonal terms in the density-matrix response.Comment: 6 pages, 1 fugure. submitted to PR

    A relativistic calculation of super-Hubble suppression of inflation with thermal dissipation

    Full text link
    We investigated the evolution of the primordial density perturbations produced by inflation with thermal dissipation. A full relativistic analysis on the evolution of initial perturbations from the warm inflation era to a radiation-dominated universe has been developed. The emphasis is on tracking the ratio between the adiabatic and the isocurvature mode of the initial perturbations. This result is employed to calculate a testable factor: the super-Hubble suppression of the power spectrum of the primordial perturbations. We show that based on the warm inflation scenario, the super-Hubble suppression factor, ss, for an inflation with thermal dissipation is at least 0.5. This prediction does not depend on the details of the model parameters. If ss is larger than 0.5, it implies that the friction parameter Γ\Gamma is larger than the Hubble expansion parameter HH during the inflation era.Comment: 22 pages, 3 figures, use RevTex, accepted by Class. Quant. Gra

    Theoretical Evidence for the Berry-Phase Mechanism of Anomalous Hall Transport: First-principles Studies on CuCr2_2Se4x_{4-x}Brx_x

    Get PDF
    To justify the origin of anomalous Hall effect (AHE), it is highly desirable to have the system parameters tuned continuously. By quantitative calculations, we show that the doping dependent sign reversal in CuCr2_{2}Se4x_{4-x}Brx_{x}, observed but not understood, is nothing but direct evidence for the Berry-Phase mechanism of AHE. The systematic calculations well explain the experiment data for the whole doping range where the impurity scattering rates is changed by several orders with Br substitution. Further sign change is also predicted, which may be tested by future experiments.Comment: 4 page

    Orbital-quenching-induced magnetism in Ba_2NaOsO_6

    Full text link
    The double perovskite \bnoo with heptavalent Os (d1d^1) is observed to remain in the ideal cubic structure ({\it i.e.} without orbital ordering) despite single occupation of the t2gt_{2g} orbitals, even in the ferromagnetically ordered phase below 6.8 K. Analysis based on the {\it ab initio} dispersion expressed in terms of an Os t2gt_{2g}-based Wannier function picture, spin-orbit coupling, Hund's coupling, and strong Coulomb repulsion shows that the magnetic OsO6_6 cluster is near a moment-less condition due to spin and orbital compensation. Quenching (hybridization) then drives the emergence of the small moment. This compensation, unprecedented in transition metals, arises in a unified picture that accounts for the observed Mott insulating behavior.Comment: in press at Europhysics Letter

    Universal bifurcation property of two- or higher-dimensional dissipative systems in parameter space: Why does 1D symbolic dynamics work so well?

    Full text link
    The universal bifurcation property of the H\'enon map in parameter space is studied with symbolic dynamics. The universal-LL region is defined to characterize the bifurcation universality. It is found that the universal-LL region for relative small LL is not restricted to very small bb values. These results show that it is also a universal phenomenon that universal sequences with short period can be found in many nonlinear dissipative systems.Comment: 10 pages, figures can be obtained from the author, will appeared in J. Phys.
    corecore