543 research outputs found

    Chern-Simons functional and the no-boundary proposal in Bianchi IX quantum cosmology

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    The Chern-Simons functional SCSS_{\rm CS} is an exact solution to the Ashtekar-Hamilton-Jacobi equation of general relativity with a nonzero cosmological constant. In this paper we consider SCSS_{\rm CS} in Bianchi type IX cosmology with S3S^3 spatial surfaces. We show that among the classical solutions generated by~SCSS_{\rm CS}, there is a two-parameter family of Euclidean spacetimes that have a regular NUT-type closing. When two of the three scale factors are equal, these spacetimes reduce to a one-parameter family within the Euclidean Taub-NUT-de~Sitter metrics. For a nonzero cosmological constant, exp(iSCS)\exp(iS_{\rm CS}) therefore provides a semiclassical estimate to the Bianchi~IX no-boundary wave function in Ashtekar's variables.Comment: 9 pages, REVTeX v3.0. (One reference added.

    Engaging with History after Macpherson

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    The Race Relations Amendment Act (2000) identifies a key role for education, and more specifically history, in promoting ‘race equality’ in Britain. In this article Ian Grosvenor and Kevin Myers consider the extent of young people’s current engagement with the history of ‘diversity, change and immigration’ which underpins the commitment to ‘race equality’. Finding that in many of Britain’s schools and universities a singular and exclusionary version of history continues to dominate the curriculum, they go on to consider the reasons for the neglect of multiculturalism. The authors identify the development of an aggressive national identity that depends on the past for its legitimacy and argue that this sense of the past is an important obstacle to future progress

    Gauge fixing and the Hamiltonian for cylindrical spacetimes

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    We introduce a complete gauge fixing for cylindrical spacetimes in vacuo that, in principle, do not contain the axis of symmetry. By cylindrically symmetric we understand spacetimes that possess two commuting spacelike Killing vectors, one of them rotational and the other one translational. The result of our gauge fixing is a constraint-free model whose phase space has four field-like degrees of freedom and that depends on three constant parameters. Two of these constants determine the global angular momentum and the linear momentum in the axis direction, while the third parameter is related with the behavior of the metric around the axis. We derive the explicit expression of the metric in terms of the physical degrees of freedom, calculate the reduced equations of motion and obtain the Hamiltonian that generates the reduced dynamics. We also find upper and lower bounds for this reduced Hamiltonian that provides the energy per unit length contained in the system. In addition, we show that the reduced formalism constructed is well defined and consistent at least when the linear momentum in the axis direction vanishes. Furthermore, in that case we prove that there exists an infinite number of solutions in which all physical fields are constant both in the surroundings of the axis and at sufficiently large distances from it. If the global angular momentum is different from zero, the isometry group of these solutions is generally not orthogonally transitive. Such solutions generalize the metric of a spinning cosmic string in the region where no closed timelike curves are present.Comment: 12 pages, accepted for publication in Physical Review

    Public trust and 'ethics review' as a commodity: the case of Genomics England Limited and the UK's 100,000 genomes project.

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    The UK Chief Medical Officer's 2016 Annual Report, Generation Genome, focused on a vision to fully integrate genomics into all aspects of the UK's National Health Service (NHS). This process of integration, which has now already begun, raises a wide range of social and ethical concerns, many of which were discussed in the final Chapter of the report. This paper explores how the UK's 100,000 Genomes Project (100 kGP)-the catalyst for Generation Genome, and for bringing genomics into the NHS-is negotiating these ethical concerns. The UK's 100 kGP, promoted and delivered by Genomics England Limited (GEL), is an innovative venture aiming to sequence 100,000 genomes from NHS patients who have a rare disease, cancer, or an infectious disease. GEL has emphasised the importance of ethical governance and decision-making. However, some sociological critique argues that biomedical/technological organisations presenting themselves as 'ethical' entities do not necessarily reflect a space within which moral thinking occurs. Rather, the 'ethical work' conducted (and displayed) by organisations is more strategic, relating to the politics of the organisation and the need to build public confidence. We set out to explore whether GEL's ethical framework was reflective of this critique, and what this tells us more broadly about how genomics is being integrated into the NHS in response to the ethical and social concerns raised in Generation Genome. We do this by drawing on a series of 20 interviews with individuals associated with or working at GEL

    Impact of Long-Term Swine and Poultry Manure Application on Soil and Water Resources in Eastern Oklahoma

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    The Oklahoma Agricultural Experiment Station periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311

    Qatar-2: A K dwarf orbited by a transiting hot Jupiter and a more massive companion in an outer orbit

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    We report the discovery and initial characterization of Qatar-2b, a hot Jupiter transiting a V = 13.3 mag K dwarf in a circular orbit with a short period, P_ b = 1.34 days. The mass and radius of Qatar-2b are M_p = 2.49 M_j and R_p = 1.14 R_j, respectively. Radial-velocity monitoring of Qatar-2 over a span of 153 days revealed the presence of a second companion in an outer orbit. The Systemic Console yielded plausible orbits for the outer companion, with periods on the order of a year and a companion mass of at least several M_j. Thus Qatar-2 joins the short but growing list of systems with a transiting hot Jupiter and an outer companion with a much longer period. This system architecture is in sharp contrast to that found by Kepler for multi-transiting systems, which are dominated by objects smaller than Neptune, usually with tightly spaced orbits that must be nearly coplanar
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