21,776 research outputs found

    Four Easy Steps to a Fiscal Train Wreck: The Florida How-To Guide

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    This report is the second of three reports that address the fiscal conditions of other states, explores the factors that explain the conditions, and the likely future trends. FRC Report 13

    Household Tax Burden Effects from Replacing Ad Valorem Taxes with Additional Sales Tax Levies - Brief

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    This brief estimates net tax effects across income classes from a sales tax for property tax swap; where Georgia property taxes are reduced and state sales taxes increased. FRC Brief 19

    A new look at microlensing limits on dark matter in the Galactic halo

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    The motivation for this paper is to review the limits set on the MACHO content of the Galactic halo by microlensing experiments in the direction of the Large Magellanic Cloud. This has been prompted by recent measurements of the Galactic rotation curve, which suggest that the limits have been biassed by the assumption of an over-massive halo. The paper first discusses the security of the detection efficiency calculations which are central to deriving the MACHO content of the Galactic halo. It then sets out to compare the rotation curves from various halo models with recent observations, with a view to establishing what limits can be put on an all-MACHO halo. The main thrust of the paper is to investigate whether lighter halo models which are consistent with microlensing by an all-MACHO halo are also consistent with recent measures of the Galactic rotation curve. In this case the population of bodies discovered by the MACHO collaboration would make up the entire dark matter content of the Galactic halo. The main result of this paper is that it is easy to find low mass halo models consistent with the observed Galactic rotation curve, which also imply an optical depth to microlensing similar to that found by the MACHO collaboration. This means that all-MACHO halos cannot be ruled out on the basis of their observations. In conclusion, limits placed on the MACHO content of the Galactic halo from microlensing surveys in the Magellanic Clouds are inconsistent and model dependent, and do not provide a secure basis for rejecting an all-MACHO halo.Comment: 8 pages, 4 figures, accepted for publication in A&

    Foreign Acquisitions in the United States: A Challenge to the Potential Competition Doctrine

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    Investigations leading to the development of a primary zinc-silver oxide battery of improved performance characteristics progress report no. 11, 1 may - 31 may 1964

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    Zinc-silver oxide battery design for improved and activated charge retention, voltage control, and temperature stabilit

    Time Dilation and Quasar Variability

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    The timescale of quasar variability is widely expected to show the effects of time dilation. In this paper we analyse the Fourier power spectra of a large sample of quasar light curves to look for such an effect. We find that the timescale of quasar variation does not increase with redshift as required by time dilation. Possible explanations of this result all conflict with widely held consensus in the scientific community.Comment: 6 pages including 3 figures. Accepted for publication in ApJ Letter
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