34 research outputs found

    On the symmetries of BF models and their relation with gravity

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    The perturbative finiteness of various topological models (e.g. BF models) has its origin in an extra symmetry of the gauge-fixed action, the so-called vector supersymmetry. Since an invariance of this type also exists for gravity and since gravity is closely related to certain BF models, vector supersymmetry should also be useful for tackling various aspects of quantum gravity. With this motivation and goal in mind, we first extend vector supersymmetry of BF models to generic manifolds by incorporating it into the BRST symmetry within the Batalin-Vilkovisky framework. Thereafter, we address the relationship between gravity and BF models, in particular for three-dimensional space-time.Comment: 29 page

    Symmetries of topological field theories in the BV-framework

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    Topological field theories of Schwarz-type generally admit symmetries whose algebra does not close off-shell, e.g. the basic symmetries of BF models or vector supersymmetry of the gauge-fixed action for Chern-Simons theory (this symmetry being at the origin of the perturbative finiteness of the theory). We present a detailed discussion of all these symmetries within the algebraic approach to the Batalin-Vilkovisky formalism. Moreover, we discuss the general algebraic construction of topological models of both Schwarz- and Witten-type.Comment: 30 page

    Earth as a Tool for Astrobiology—A European Perspective

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    Christmas Disease (Haemophilia B) in a Girl with Deletion of the Short Arm of One X-Chromosome (Functional Turner Syndrome)

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    A I-year-old girl with severe Christmas disease and a factor IX content less than 1% of normal is described. The family history was negative and coagulation studies on her relatives were normal. Genetic investigation showed an XXp-karyotype with deletion of the short arm of one X-chromosome, a cytogenetic variant of Turner syndrome. The transmission pathway of the haemophilia gene is discussed
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