115,703 research outputs found

    Thermodynamical Properties and Quasi-localized Energy of the Stringy Dyonic Black Hole Solution

    Full text link
    In this article, we calculate the heat flux passing through the horizon .TSrh. {\bf TS}|_{r_h} and the difference of energy between the Einstein and M{\o}ller prescription within the region M{\cal M}, in which is the region between outer horizon H+{\cal H}_+ and inner horizon H{\cal H}_-, for the modified GHS solution, KLOPP solution and CLH solution. The formula . E_{\rm Einstein}|_{\cal M} = . E_{\rm M{\o}ller}|_{\cal M} - \sum_{\partial {\cal M}} {\bf TS}$ is obeyed for the mGHS solution and the KLOPP solution, but not for the CLH solution. Also, we suggest a RN-like stringy dyonic black hole solution, which comes from the KLOPP solution under a dual transformation, and its thermodynamical properties are the same as the KLOPP solution

    A scattering theory of ultrarelativistic solitons

    Get PDF
    We construct a perturbative framework for understanding the collision of solitons (more precisely, solitary waves) in relativistic scalar field theories. Our perturbative framework is based on the suppression of the space-time interaction area proportional to 1/(γv)1/(\gamma v), where vv is the relative velocity of an incoming solitary wave and γ=1/1v21\gamma = 1/\sqrt{1-v^2} \gg 1. We calculate the leading order results for collisions of (1+1) dimensional kinks in periodic potentials, and provide explicit, closed form expressions for the phase shift and the velocity change after the collisions. We find excellent agreement between our results and detailed numerical simulations. Crucially, our perturbation series is controlled by a kinematic parameter, and hence not restricted to small deviations around integrable cases such as the Sine-Gordon model.Comment: v3: 43 pages, 10 figures, references added, matches version accepted for publication in PR

    Energy Distribution in 2d Stringy Black Hole Backgrounds

    Get PDF
    We utilize Moller's and Einstein's energy-momentum complexes in order to explicitly evaluate the energy distributions associated with the two-dimensional "Schwarzschild" and "Reissner-Nordstrom" black hole backgrounds. While Moller's prescription provides meaningful physical results, Einstein's prescription fails to do so in the aforementioned gravitational backgrounds. These results hold for all two-dimensional static black hole geometries. The results obtained within this context are exploited in order Seifert's hypothesis to be investigated.Comment: 17 pages, LaTeX, v2: acknowledgements added, to appear in Int.J.Mod.Phys.

    Probing the low-x structure of nuclear matter with diffractive hadron production in pA collisions

    Get PDF
    We argue that hadron production in coherent diffraction of proton on a heavy nucleus provides a very sensitive probe of the low-x QCD dynamics. This process probes the BFKL dynamics in proton and the non-linear gluon evolution in nucleus. We calculate the diffractive hadron production cross sections in the RHIC and LHC kinematic regions. To study the nuclear effects we introduce the diffractive nuclear modification factor. We show that unlike the nuclear modification factor for inclusive hadron production that has a very interesting dynamics at RHIC but is expected to be almost completely saturated at the LHC, the nuclear modification factor for diffractive production exhibits a non-trivial behavior both at RHIC and LHC.Comment: 18 pages, 7 figure

    Landscape Predictions from Cosmological Vacuum Selection

    Full text link
    In BP models with hundreds of fluxes, we compute the effects of cosmological dynamics on the probability distribution of landscape vacua. Starting from generic initial conditions, we find that most fluxes are dynamically driven into a different and much narrower range of values than expected from landscape statistics alone. Hence, cosmological evolution will access only a tiny fraction of the vacua with small cosmological constant. This leads to a host of sharp predictions. Unlike other approaches to eternal inflation, the holographic measure employed here does not lead to "staggering", an excessive spread of probabilities that would doom the string landscape as a solution to the cosmological constant problem.Comment: 15 pages, 6 figures, v4 prd format, minor editin

    Photodetachment of H^{-} near a partial reflecting surface

    Full text link
    Theoretical and interpretative study on the subject of photodetachment of H^{-} near a partial reflecting surface is presented, and the absorption effect of the surface is investigated on the total and differential cross sections using a theoretical imaging method. To understand the absorption effect, a reflection parameter KK is introduced as a multiplicative factor to the outgoing detached-electron wave of H^- propagating toward the wall. The reflection parameter measures, how much electron wave would reflect from the surface; K=0 corresponds to no reflection and K=1 corresponds to the total reflection.Comment: 8 pages, 4 figure

    The Energy of the Gamma Metric in the M{\o}ller Prescription

    Get PDF
    We obtain the energy distribution of the gamma metric using the energy-momentum complex of M{\o}ller. The result is the same as obtained by Virbhadra in the Weinberg prescription

    Gluon recombination in high parton density QCD: inclusive pion production

    Get PDF
    We argue that the collinear factorization of the fragmentation functions in high energy hadron and nuclei collisions breaks down at transverse momenta kT < Qs/g due to high parton densities in the colliding hadrons and/or nuclei. We calculate, at next-to-leading order in projectile parton density and to all orders in target parton density, the double-inclusive cross section for production of a pair of gluons in the scalar J^(PC)=0^(++) channel. Using the low energy theorems of QCD we find the inclusive cross section for pi-meson production.Comment: 24 pages, 5 figure
    corecore