4,223 research outputs found

    Stability and hyperfine structure of the four- and five-body muon-atomic clusters a+b+μea^{+} b^{+} \mu^{-} e^{-} and a+b+μeea^{+} b^{+} \mu^{-} e^{-} e^{-}

    Full text link
    Based on the results of accurate variational calculations we demonstrate stability of the five-body negatively charged ions a+b+μeea^{+} b^{+} \mu^{-} e^{-} e^{-}. Each of these five-body ions contains two electrons ee^{-}, one negatively charged muon μ\mu^{-} and two nuclei of the hydrogen isotopes a,b=(p,d,t)a, b = (p, d, t). The bound state properties of these five-body ions, including their hyperfine structure, are briefly discussed. We also investigate the hyperfine structure of the ground states of the four-body muonic quasi-atoms a+b+μea^{+} b^{+} \mu^{-} e^{-}. In particular, we determine the hyperfine structure splittings for the ground state of the four-body muonic quasi-atoms: p+d+μep^{+} d^{+} \mu^{-} e^{-} and p+t+μep^{+} t^{+} \mu^{-} e^{-}

    Energy flux through the horizon in the black hole-domain wall systems

    Full text link
    We study various configurations in which a domain wall (or cosmic string), described by the Nambu-Goto action, is embedded in a background space-time of a black hole in (3+1)(3+1) and higher dimensional models. We calculate energy fluxes through the black hole horizon. In the simplest case, when a static domain wall enters the horizon of a static black hole perperdicularly, the energy flux is zero. In more complicated situations, where parameters which describe the domain wall surface are time and position dependent, the flux is non-vanishing is principle. These results are of importance in various conventional cosmological models which accommodate the existence of domain walls and strings and also in brane world scenarios.Comment: references added, accepted for publication in JHE

    On the bound state of the antiproton-deuterium-tritium ion

    Full text link
    The properties of the weakly-bound S(L=0)S(L = 0)-state in the pˉdt\bar{p}dt ion are investigated with the use of the results of highly accurate computations. The hyperfine structure splitting of this ion is investigated. We also evaluate the life-time of the pˉdt\bar{p}dt ion against the nuclear (d,t)(d,t)-fusion and discuss a possibility to evaluate the corresponding annihilation rate(s)

    Thermonuclear burn-up in deuterated methane CD4CD_4

    Full text link
    The thermonuclear burn-up of highly compressed deuterated methane CD4_4 is considered in the spherical geometry. The minimal required values of the burn-up parameter x=ρ0rfx = \rho_0 \cdot r_f are determined for various temperatures TT and densities ρ0\rho_0. It is shown that thermonuclear burn-up in CD4CD_4 becomes possible in practice if its initial density ρ0\rho_0 exceeds 5103\approx 5 \cdot 10^3 gcm3g \cdot cm^{-3}. Burn-up in CD2_2T2_2 methane requires significantly (\approx 100 times) lower compressions. The developed approach can be used in order to compute the critical burn-up parameters in an arbitrary deuterium containing fuel

    Statistical Mechanics of Charged Black Holes in Induced Einstein-Maxwell Gravity

    Get PDF
    The statistical origin of the entropy of charged black holes in models of induced Einstein-Maxwell gravity is investigated. The constituents inducing the Einstein-Maxwell action are charged and interact with an external gauge potential. This new feature, however, does not change divergences of the statistical-mechanical entropy of the constituents near the horizon. It is demonstrated that the mechanism of generation of the Bekenstein-Hawking entropy in induced gravity is universal and it is basically the same for charged and neutral black holes. The concrete computations are carried out for induced Einstein-Maxwell gravity with a negative cosmological constant in three space-time dimensions.Comment: 16 pages, latex, no figure

    Gauge field theory for Poincar\'{e}-Weyl group

    Full text link
    On the basis of the general principles of a gauge field theory the gauge theory for the Poincar\'{e}-Weyl group is constructed. It is shown that tetrads are not true gauge fields, but represent functions from true gauge fields: Lorentzian, translational and dilatational ones. The equations of gauge fields which sources are an energy-momentum tensor, orbital and spin momemta, and also a dilatational current of an external field are obtained. A new direct interaction of the Lorentzian gauge field with the orbital momentum of an external field appears, which describes some new effects. Geometrical interpretation of the theory is developed and it is shown that as a result of localization of the Poincar\'{e}-Weyl group spacetime becomes a Weyl-Cartan space. Also the geometrical interpretation of a dilaton field as a component of the metric tensor of a tangent space in Weyl-Cartan geometry is proposed.Comment: LaTex, 27 pages, no figure

    Continuous Self-Similarity Breaking in Critical Collapse

    Full text link
    This paper studies near-critical evolution of the spherically symmetric scalar field configurations close to the continuously self-similar solution. Using analytic perturbative methods, it is shown that a generic growing perturbation departs from the critical Roberts solution in a universal way. We argue that in the course of its evolution, initial continuous self-similarity of the background is broken into discrete self-similarity with echoing period Δ=2π=4.44\Delta = \sqrt{2}\pi = 4.44, reproducing the symmetries of the critical Choptuik solution.Comment: RevTeX 3.1, 28 pages, 5 figures; discussion rewritten to clarify several issue

    Black Hole Entropy in Induced Gravity: Reduction to 2D Quantum Field Theory on the Horizon

    Full text link
    It is argued that degrees of freedom responsible for the Bekenstein-Hawking entropy of a black hole in induced gravity are described by two dimensional quantum field theory defined on the bifurcation surface of the horizon. This result is proved for a class of induced gravity models with scalar, spinor and vector heavy constituents.Comment: 19 pages, latex, no figure
    corecore