262 research outputs found

    Anthropics and Myopics: Conditional Probabilities and the Cosmological Constant

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    We re-examine claims that anthropic arguments provide an explanation for the observed smallness of the cosmological constant, and argue that correlations between the cosmological constant value and the existence of life can be demonstrated only under restrictive assumptions. Causal effects are more subtle to uncover.Comment: revised to PRL format, additional references and discussion to related work revise

    Alternative approach to b>sγb->s \gamma in the uMSSM

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    The gluino contributions to the C7,8C'_{7,8} Wilson coefficients for b>sγb->s \gamma are calculated within the unconstrained MSSM. New stringent bounds on the δ23RL\delta^{RL}_{23} and δ23RR\delta^{RR}_{23} mass insertion parameters are obtained in the limit in which the SM and SUSY contributions to C7,8C_{7,8} approximately cancel. Such a cancellation can plausibly appear within several classes of SUSY breaking models in which the trilinear couplings exhibit a factorized structure proportional to the Yukawa matrices. Assuming this cancellation takes place, we perform an analysis of the b>sγb->s \gamma decay. We show that in a supersymmetric world such an alternative is reasonable and it is possible to saturate the b>sγb->s \gamma branching ratio and produce a CP asymmetry of up to 20%, from only the gluino contribution to C7,8C'_{7,8} coefficients. Using photon polarization a LR asymmetry can be defined that in principle allows for the C7,8C_{7,8} and C7,8C'_{7,8} contributions to the b>sγb->s \gamma decay to be disentangled. In this scenario no constraints on the ``sign of μ\mu'' can be derived.Comment: LaTeX2e, 23 pages, 7 ps figure, needs package epsfi

    Downtown Manor and Outer Limits July Schedule

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    Flyer showing the July weekend schedule for Downtown Manor and Outer Limits.https://digitalcommons.buffalostate.edu/mdlevents/1003/thumbnail.jp

    Quantum Weak Coin Flipping

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    We investigate weak coin flipping, a fundamental cryptographic primitive where two distrustful parties need to remotely establish a shared random bit. A cheating player can try to bias the output bit towards a preferred value. For weak coin flipping the players have known opposite preferred values. A weak coin-flipping protocol has a bias ϵ\epsilon if neither player can force the outcome towards their preferred value with probability more than 12+ϵ\frac{1}{2}+\epsilon. While it is known that all classical protocols have ϵ=12\epsilon=\frac{1}{2}, Mochon showed in 2007 [arXiv:0711.4114] that quantumly weak coin flipping can be achieved with arbitrarily small bias (near perfect) but the best known explicit protocol has bias 1/61/6 (also due to Mochon, 2005 [Phys. Rev. A 72, 022341]). We propose a framework to construct new explicit protocols achieving biases below 1/61/6. In particular, we construct explicit unitaries for protocols with bias approaching 1/101/10. To go below, we introduce what we call the Elliptic Monotone Align (EMA) algorithm which, together with the framework, allows us to numerically construct protocols with arbitrarily small biases.Comment: 98 pages split into 3 parts, 10 figures; For updates and contact information see https://atulsingharora.github.io/WCF. Version 2 has minor improvements. arXiv admin note: text overlap with arXiv:1402.7166 by other author

    On non-gaussianities in single-field inflation

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    We study the impact of higher dimension operators in the inflaton Lagrangian on the non-gaussianity of the scalar spectrum. These terms can strongly enhance the effect without spoiling slow-roll, though it is difficult to exceed f_NL ~ 1, because the scale which suppresses the operators cannot be too low, if we want the effective field theory description to make sense. In particular we explicitly calculate the 3-point function given by an higher derivative interaction of the form (\nabla\phi)^4, which is expected to give the most important contribution. The angular dependence of the result turns out to be quite different from the minimal case without higher dimension operators.Comment: 10 page

    The effects of aging of scientists on their publication and citation patterns

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    The average age at which U.S. researchers get their first grant from NIH has increased from 34.3 in 1970, to 41.7 in 2004. These data raise the crucial question of the effects of aging on the scientific creativity and productivity of researchers. Those who worry about the aging of scientists usually believe that the younger they are the more creative and productive they will be. Using a large population of 13,680 university professors in Quebec, we show that, while scientific productivity rises sharply between 28 and 40, it increases at a slower pace between 41 and 50 and stabilizes afterward until retirement for the most active researchers. The average scientific impact per paper decreases linearly until 50-55 years old, but the average number of papers in highly cited journals and among highly cited papers rises continuously until retirement. Our results clearly show for the first time the natural history of the scientific productivity of scientists over their entire career and bring to light the fact that researchers over 55 still contribute significantly to the scientific community by producing high impact papers.Comment: 12 pages, 4 figure

    Cancer effects of formaldehyde: a proposal for an indoor air guideline value

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    Formaldehyde is a ubiquitous indoor air pollutant that is classified as “Carcinogenic to humans (Group 1)” (IARC, Formaldehyde, 2-butoxyethanol and 1-tert-butoxypropanol-2-ol. IARC monographs on the evaluation of carcinogenic risks to humans, vol 88. World Health Organization, Lyon, pp 39–325, 2006). For nasal cancer in rats, the exposure–response relationship is highly non-linear, supporting a no-observed-adverse-effect level (NOAEL) that allows setting a guideline value. Epidemiological studies reported no increased incidence of nasopharyngeal cancer in humans below a mean level of 1 ppm and peak levels below 4 ppm, consistent with results from rat studies. Rat studies indicate that cytotoxicity-induced cell proliferation (NOAEL at 1 ppm) is a key mechanism in development of nasal cancer. However, the linear unit risk approach that is based on conservative (“worst-case”) considerations is also used for risk characterization of formaldehyde exposures. Lymphohematopoietic malignancies are not observed consistently in animal studies and if caused by formaldehyde in humans, they are high-dose phenomenons with non-linear exposure–response relationships. Apparently, these diseases are not reported in epidemiological studies at peak exposures below 2 ppm and average exposures below 0.5 ppm. At the similar airborne exposure levels in rodents, the nasal cancer effect is much more prominent than lymphohematopoietic malignancies. Thus, prevention of nasal cancer is considered to prevent lymphohematopoietic malignancies. Departing from the rat studies, the guideline value of the WHO (Air quality guidelines for Europe, 2nd edn. World Health Organization, Regional Office for Europe, Copenhagen, pp 87–91, 2000), 0.08 ppm (0.1 mg m−3) formaldehyde, is considered preventive of carcinogenic effects in compliance with epidemiological findings

    Photobiological safety of the recently introduced energy efficient household lamps

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    Objectives: Nowadays more and more newly introduced light sources (tungsten-halogen, compact fluorescent (CFL) and light-emitting diode (LED) lamps) are used in households. It is important to know whether their radiation poses any possible risk for human health or not. These light sources emit optical radiation not solely in the visible spectrum. Other bands emitted by these sources, i.e., ultraviolet and infrared, are potentially hazardous for human health. The visible light, especially the blue light, could also damage human retina. The purpose of this study was to determine the ultraviolet (UV) and blue light (BL) emissions from halogen bulbs, CFLs and LED lamps, and to evaluate them from the point of view of possible health risks for general public. Material and Methods: The exposure of UV and BL emissions from 19 types of CFLs, 11 types of halogen lamps and 4 types of LED lamps produced by different manufacturers were measured at 200 mm distance from the source. Results: The exposures to UV and BL were below the International Commission on Non-Ionizing Radiation Protection (ICNIRP) exposure limits in spite of the very conservative assumption of the assessment. Conclusions: Results of this study indicate that the UV and BL radiation from the newly introduced lamps does not exceed the current exposure limit values and thus, in comparison with the former incandescent bulbs, does not result in a higher risk for general public
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