766 research outputs found

    Graviton emission from simply rotating Kerr-de Sitter black holes: Transverse traceless tensor graviton modes

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    In this article we present results for tensor graviton modes (in seven dimensions and greater, n3n\geq 3) for greybody factors of Kerr-dS black holes and for Hawking radiation from simply rotating (n+4)-dimensional Kerr black holes. Although there is some subtlety with defining the Hawking temperature of a Kerr-dS black hole, we present some preliminary results for emissions assuming the standard Hawking normalization and a Bousso-Hawking-like normalization.Comment: 12 pages, 18 figure

    Black hole quasinormal modes using the asymptotic iteration method

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    In this article we show that the asymptotic iteration method (AIM) allows one to numerically find the quasinormal modes of Schwarzschild and Schwarzschild de Sitter (SdS) black holes. An added benefit of the method is that it can also be used to calculate the Schwarzschild anti-de Sitter (SAdS) quasinormal modes for the case of spin zero perturbations. We also discuss an improved version of the AIM, more suitable for numerical implementation.Comment: 10 pages, LaTeX; references added; substantially expanded versio

    Split fermion quasi-normal modes

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    In this paper we use the conformal properties of the spinor field to show how we can obtain the fermion quasi-normal modes for a higher dimensional Schwarzschild black hole. These modes are of interest in so called split fermion models, where quarks and leptons are required to exist on different branes in order to keep the proton stable. As has been previously shown, for brane localized fields, the larger the number of dimensions the faster the black hole damping rate. Moreover, we also present the analytic forms of the quasi-normal frequencies in both the large angular momentum and the large mode number limits.Comment: 11 pages, 7 figures, version 2 added reference

    Angular Eigenvalues of Higher-Dimensional Kerr-(A)dS Black Holes with Two Rotations

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    In this paper, following the work of Chen, L\"u and Pope, we present the general metric for Kerr-(A)dS black holes with two rotations. The corresponding Klein-Gordon equation is separated explicitly, from which we develop perturbative expansions for the angular eigenvalues in powers of the rotation parameters with D6D\geq 6.Comment: 10 pages, no figures. To appear in the proceedings of 2011 Shanghai Asia-Pacific School and Workshop on Gravitatio

    Bulk dominated fermion emission on a Schwarzschild background

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    Using the WKBJ approximation, and the Unruh method, we obtain semi-analytic expressions for the absorption probability (in all energy regimes) for Dirac fermions on a higher dimensional Schwarzschild background. We present an analytic expression relating the absorption probability to the absorption cross-section, and then use these results to plot the emission rates to third order in the WKBJ approximation. The set-up we use is sufficiently general such that it could also easily be applied to any spherically symmetric background in dd-dimensions. Our results lead to the interesting conclusion that for d>5d>5 bulk fermion emission dominates brane localised emission. This is an example contrary to the conjecture that black holes radiate mainly on the brane.Comment: 13 pages, 3 figure

    Fermion excitations of a tense brane black hole

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    By finding the spinor eigenvalues for a single deficit angle (d-2)-sphere, we derive the radial potential for fermions on a d-dimensional black hole background that is embedded on a codimension two brane with conical singularity, where the deficit angle is related to the brane tension. From this we obtain the quasi-normal mode spectrum for bulk fermions on such a background. As a byproduct of our method, this also gives a rigorous proof for integer spin fields on the deficit 2-sphere.Comment: 7 pages, 1 figur

    Quasi-normal modes for doubly rotating black holes

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    Based on the work of Chen, L\"u and Pope, we derive expressions for the D6D\geq 6 dimensional metric for Kerr-(A)dS black holes with two independent rotation parameters and all others set equal to zero: a10,a20,a3=a4=...=0a_1\neq 0, a_2\neq0, a_3=a_4=...=0. The Klein-Gordon equation is then explicitly separated on this background. For D6D\geq 6 this separation results in a radial equation coupled to two generalized spheroidal angular equations. We then develop a full numerical approach that utilizes the Asymptotic Iteration Method (AIM) to find radial Quasi-Normal Modes (QNMs) of doubly rotating flat Myers-Perry black holes for slow rotations. We also develop perturbative expansions for the angular quantum numbers in powers of the rotation parameters up to second order.Comment: RevTeX 4-1, various figure

    HPV Vaccine Acceptability Among Men: A Systematic Review and Meta-Analysis

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    Objective To understand rates of human papillomavirus (HPV) vaccine acceptability and factors correlated with HPV vaccine acceptability. Design Meta-Analyses of cross-sectional studies. Data sources We used a comprehensive search strategy across multiple electronic databases with no date or language restrictions to locate studies that examined rates and/or correlates of HPV vaccine acceptability. Search keywords included vaccine, acceptability and all terms for HPV. Review methods We calculated mean HPV vaccine acceptability across studies. We conducted meta-Analysis using a random effects model on studies reporting correlates of HPV vaccine acceptability. All studies were assessed for risk of bias. Results Of 301 identified studies, 29 were included. Across 22 studies (n=8360), weighted mean HPV vaccine acceptability=50.4 (SD 21.5) (100-point scale). Among 16 studies (n=5048) included in meta-Analyses, perceived HPV vaccine benefits, anticipatory regret, partner thinks one should get vaccine and healthcare provider recommendation had medium effect sizes, and the following factors had small effect sizes on HPV vaccine acceptability: perceived HPV vaccine effectiveness, need for multiple shots, fear of needles, fear of side effects, supportive/accepting social environment, perceived risk/susceptibility to HPV, perceived HPV severity, number of lifetime sexual partners, having a current sex partner, non-receipt of hepatitis B vaccine, smoking cigarettes, history of sexually transmitted infection, HPV awareness, HPV knowledge, cost, logistical barriers, being employed and non-white ethnicity. Conclusions Public health campaigns that promote positive HPV vaccine attitudes and awareness about HPV risk in men, and interventions to promote healthcare provider recommendation of HPV vaccination for boys and mitigate obstacles due to cost and logistical barriers may support HPV vaccine acceptability for men. Future investigations employing rigorous designs, including intervention studies, are needed to support effective HPV vaccine promotion among men

    Asymptotic iteration method for spheroidal harmonics of higher-dimensional Kerr-(A)dS black holes

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    In this work we calculate the angular eigenvalues of the (n+4)(n+4)-dimensional {\it simply} rotating Kerr-(A)dS spheroidal harmonics using the Asymptotic Iteration Method (AIM). We make some comparisons between this method and that of the Continued Fraction Method (CFM) and use the latter to check our results. We also present analytic expressions for the small rotation limit up to O(c3)O(c^3) with the coefficient of each power up to O(α2)O(\alpha^2), where c=aωc=a\omega and α=a2Λ\alpha=a^2 \Lambda (aa is the angular velocity, ω\omega the frequency and Λ\Lambda the cosmological constant).Comment: 7 pages, 6 tables, LaTeX; typos corrected and reference added; table clarity improved, 2 figures and more references added (now 9 pages
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