1,244 research outputs found

    Stationary perturbations and infinitesimal rotations of static Einstein-Yang-Mills configurations with bosonic matter

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    Using the Kaluza-Klein structure of stationary spacetimes, a framework for analyzing stationary perturbations of static Einstein-Yang-Mills configurations with bosonic matter fields is presented. It is shown that the perturbations giving rise to non-vanishing ADM angular momentum are governed by a self-adjoint system of equations for a set of gauge invariant scalar amplitudes. The method is illustrated for SU(2) gauge fields, coupled to a Higgs doublet or a Higgs triplet. It is argued that slowly rotating black holes arise generically in self-gravitating non-Abelian gauge theories with bosonic matter, whereas, in general, soliton solutions do not have rotating counterparts.Comment: 8 pages, revtex, no figure

    Rotating Einstein-Yang-Mills Black Holes

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    We construct rotating hairy black holes in SU(2) Einstein-Yang-Mills theory. These stationary axially symmetric black holes are asymptotically flat. They possess non-trivial non-Abelian gauge fields outside their regular event horizon, and they carry non-Abelian electric charge. In the limit of vanishing angular momentum, they emerge from the neutral static spherically symmetric Einstein-Yang-Mills black holes, labelled by the node number of the gauge field function. With increasing angular momentum and mass, the non-Abelian electric charge of the solutions increases, but remains finite. The asymptotic expansion for these black hole solutions includes non-integer powers of the radial variable.Comment: 63 pages, 10 figure

    Perturbation theory for self-gravitating gauge fields I: The odd-parity sector

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    A gauge and coordinate invariant perturbation theory for self-gravitating non-Abelian gauge fields is developed and used to analyze local uniqueness and linear stability properties of non-Abelian equilibrium configurations. It is shown that all admissible stationary odd-parity excitations of the static and spherically symmetric Einstein-Yang-Mills soliton and black hole solutions have total angular momentum number â„“=1\ell = 1, and are characterized by non-vanishing asymptotic flux integrals. Local uniqueness results with respect to non-Abelian perturbations are also established for the Schwarzschild and the Reissner-Nordstr\"om solutions, which, in addition, are shown to be linearly stable under dynamical Einstein-Yang-Mills perturbations. Finally, unstable modes with â„“=1\ell = 1 are also excluded for the static and spherically symmetric non-Abelian solitons and black holes.Comment: 23 pages, revtex, no figure

    There are no magnetically charged particle-like solutions of the Einstein Yang-Mills equations for Abelian models

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    We prove that there are no magnetically charged particle-like solutions for Abelian models in Einstein Yang-Mills, but for non-Abelian models the possibility remains open. An analysis of the Lie algebraic structure of the Yang-Mills fields is essential to our results. In one key step of our analysis we use invariant polynomials to determine which orbits of the gauge group contain the possible asymptotic Yang-Mills field configurations. Together with a new horizontal/vertical space decomposition of the Yang-Mills fields this enables us to overcome some obstacles and complete a dynamical system existence theorem for asymptotic solutions with nonzero total magnetic charge. We then prove that these solutions cannot be extended globally for Abelian models and begin an investigation of the details for non-Abelian models.Comment: 48 pages, 1 figur

    Rotating Hairy Black Holes

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    We construct stationary black holes in SU(2) Einstein-Yang-Mills theory, which carry angular momentum and electric charge. Possessing non-trivial non-abelian magnetic fields outside their regular event horizon, they represent non-perturbative rotating hairy black holes.Comment: 13 pages, including 4 eps figures, LaTex forma

    Existence of spinning solitons in gauge field theory

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    We study the existence of classical soliton solutions with intrinsic angular momentum in Yang-Mills-Higgs theory with a compact gauge group G\mathcal{G} in (3+1)-dimensional Minkowski space. We show that for \textit{symmetric} gauge fields the Noether charges corresponding to \textit{rigid} spatial symmetries, as the angular momentum, can be expressed in terms of \textit{surface} integrals. Using this result, we demonstrate in the case of G=SU(2)\mathcal{G}=SU(2) the nonexistence of stationary and axially symmetric spinning excitations for all known topological solitons in the one-soliton sector, that is, for 't Hooft--Polyakov monopoles, Julia-Zee dyons, sphalerons, and also vortices.Comment: 21 pages, to appear in Phys.Rev.

    Geometrical optics analysis of the short-time stability properties of the Einstein evolution equations

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    Many alternative formulations of Einstein's evolution have lately been examined, in an effort to discover one which yields slow growth of constraint-violating errors. In this paper, rather than directly search for well-behaved formulations, we instead develop analytic tools to discover which formulations are particularly ill-behaved. Specifically, we examine the growth of approximate (geometric-optics) solutions, studied only in the future domain of dependence of the initial data slice (e.g. we study transients). By evaluating the amplification of transients a given formulation will produce, we may therefore eliminate from consideration the most pathological formulations (e.g. those with numerically-unacceptable amplification). This technique has the potential to provide surprisingly tight constraints on the set of formulations one can safely apply. To illustrate the application of these techniques to practical examples, we apply our technique to the 2-parameter family of evolution equations proposed by Kidder, Scheel, and Teukolsky, focusing in particular on flat space (in Rindler coordinates) and Schwarzchild (in Painleve-Gullstrand coordinates).Comment: Submitted to Phys. Rev.

    Controlled lasing from active optomechanical resonators

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    Planar microcavities with distributed Bragg reflectors (DBRs) host, besides confined optical modes, also mechanical resonances due to stop bands in the phonon dispersion relation of the DBRs. These resonances have frequencies in the sub-terahertz (10E10-10E11 Hz) range with quality factors exceeding 1000. The interaction of photons and phonons in such optomechanical systems can be drastically enhanced, opening a new route toward manipulation of light. Here we implemented active semiconducting layers into the microcavity to obtain a vertical-cavity surface-emitting laser (VCSEL). Thereby three resonant excitations -photons, phonons, and electrons- can interact strongly with each other providing control of the VCSEL laser emission: a picosecond strain pulse injected into the VCSEL excites long-living mechanical resonances therein. As a result, modulation of the lasing intensity at frequencies up to 40 GHz is observed. From these findings prospective applications such as THz laser control and stimulated phonon emission may emerge

    Sequences of globally regular and black hole solutions in SU(4) Einstein-Yang-Mills theory

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    SU(4) Einstein-Yang-Mills theory possesses sequences of static spherically symmetric globally regular and black hole solutions. Considering solutions with a purely magnetic gauge field, based on the 4-dimensional embedding of su(2)su(2) in su(4)su(4), these solutions are labelled by the node numbers (n1,n2,n3)(n_1,n_2,n_3) of the three gauge field functions u1u_1, u2u_2 and u3u_3. We classify the various types of solutions in sequences and determine their limiting solutions. The limiting solutions of the sequences of neutral solutions carry charge, and the limiting solutions of the sequences of charged solutions carry higher charge. For sequences of black hole solutions with node structure (n,j,n)(n,j,n) and (n,n,n)(n,n,n), several distinct branches of solutions exist up to critical values of the horizon radius. We determine the critical behaviour for these sequences of solutions. We also consider SU(4) Einstein-Yang-Mills-dilaton theory and show that these sequences of solutions are analogous in most respects to the corresponding SU(4) Einstein-Yang-Mills sequences of solutions.Comment: 40 pages, 5 tables, 19 Postscript figures, use revtex.st

    Influence of Vitis xylem fluid and xylem fluid plus cecropin on growth of Xylella fastidiosa

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    Colony growth of Xylella fastidiosa (UCLA PD and STL PD strains) was quantified after incubation for 48 h in xylem fluid of Vitis rotundifolia Michx. cv. Noble and Vitis vinifera L. cv. Chardonnay. Xylem fluid was collected from grapevines in the field (dormant and growing season) and from container-grown plants in a screen house (growing season). Colony forming units·ml-1 (cfu·ml-1) were counted 15 d after plating on periwinkle wilt (PW+) medium. Colony growth was promoted or inhibited compared to PW+ medium, and was dependent on X. fastidiosa strain, plant species and source of xylem fluid. The efficacy of cecropin A and B was tested against this bacterium. Colony growth of X. fastidiosa was greatly inhibited after a 1-h-exposure to cecropin A or B. The minimum inhibitory concentration (MIC) of cecropin A or B for 100 % inhibition of X. fastidiosa was < 1 μM. The activity of cecropin B in xylem fluid of V. rotundifolia cv. Noble was progressively reduced over time from 0.2 to 24 h. When 2 and 10 μM concentrations of cecropin A and cecropin B were mixed with xylem fluid for 24 h, a substantial amount of bacterial growth occurred after subsequent plating; shorter time intervals did not degrade the cecropins and did not prevent colony growth. Cecropin B (1 μM) added to xylem fluid of V. rotundifolia cv. Noble and V. vinifera cv. Chardonnay for 24, 48, 72 and 96 h did not prevent subsequent colony growth. Colony number tended to be higher for V. rotundifolia cv. Noble than V. vinifera cv. Chardonnay. Tricine-sodium dodecyl sulphate polyacrylamide gel electrophoresis (Tricine-SDS-PAGE) of cecropin B in xylem fluid showed that cecropin B degraded completely (V. vinifera cv. Chardonnay) or almost completely (V. rotundifolia cv. Noble) after 96 h
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