69 research outputs found

    Weight Vectors of the Basic A_1^(1)-Module and the Littlewood-Richardson Rule

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    The basic representation of \A is studied. The weight vectors are represented in terms of Schur functions. A suitable base of any weight space is given. Littlewood-Richardson rule appears in the linear relations among weight vectors.Comment: February 1995, 7pages, Using AMS-Te

    Construction of the K=8 Fractional Superconformal Algebras

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    We construct the K=8 fractional superconformal algebras. There are two such extended Virasoro algebras, one of which was constructed earlier, involving a fractional spin (equivalently, conformal dimension) 6/5 current. The new algebra involves two additional fractional spin currents with spin 13/5. Both algebras are non-local and satisfy non-abelian braiding relations. The construction of the algebras uses the isomorphism between the Z_8 parafermion theory and the tensor product of two tricritical Ising models. For the special value of the central charge c=52/55, corresponding to the eighth member of the unitary minimal series, the 13/5 currents of the new algebra decouple, while two spin 23/5 currents (level-2 current algebra descendants of the 13/5 currents) emerge. In addition, it is shown that the K=8 algebra involving the spin 13/5 currents at central charge c=12/5 is the appropriate algebra for the construction of the K=8 (four-dimensional) fractional superstring.Comment: 53 pages (or 82/2 = 41 pages in reduced format

    Biconformal supergravity and the AdS/CFT conjecture

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    Biconformal supergravity models provide a new gauging of the superconformal group relevant to the Maldacena conjecture. Using the group quotient method to biconformally gauge SU(2,2|N), we generate a 16-dim superspace. We write the most general even- and odd-parity actions linear in the curvatures, the bosonic sector of which is known to descend to general relativity on a 4-dim manifold.Comment: 35 pages, adjusted group nomenclature, 1 reference and acknowledgements adde

    Entropy of Classical Histories

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    We consider a number of proposals for the entropy of sets of classical coarse-grained histories based on the procedures of Jaynes, and prove a series of inequalities relating these measures. We then examine these as a function of the coarse-graining for various classical systems, and show explicitly that the entropy is minimized by the finest-grained description of a set of histories. We propose an extension of the second law of thermodynamics to the entropy of histories. We briefly discuss the implications for decoherent or consistent history formulations of quantum mechanics.Comment: 35 pages RevTeX 3.0 + 5 figures (postscript). Minor corrections and typos. To appear in Physical Review

    Nutrition, mental health and violence: from pregnancy to postpartum Cohort of women attending primary care units in Southern Brazil - ECCAGE study

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    <p>Abstract</p> <p>Background</p> <p>Woman's nutritional status, before and during pregnancy, is a strong determinant of health outcomes in the mother and newborn. Gestational weight gain and postpartum weight retention increases risk of overweight or obesity in the future and they depend on the pregestational nutritional status and on food consumption and eating behavior during pregnancy. Eating behavior during pregnancy may be the cause or consequence of mood changes during pregnancy, especially depression, which increases likelihood of postpartum depression. In Brazil, a study carried out in the immediate postpartum period found that one in three women experienced some type of violence during pregnancy. Violence and depression are strongly associated and both exposures during pregnancy are associated with increased maternal stress and subsequent harm to the infant. The main objectives of this study are: to identify food intake and eating behaviors patterns; to estimate the prevalence of common mental disorders and the experience of violence during and after pregnancy; and to estimate the association between these exposures and infant's health and development.</p> <p>Methods/Design</p> <p>This is a cohort study of 780 pregnant women receiving care in 18 primary care units in two cities in Southern Brazil. Pregnant women were first evaluated between the 16<sup>th </sup>and 36<sup>th </sup>week of pregnancy at a prenatal visit. Follow-up included immediate postpartum assessment and around the fifth month postpartum. Information was obtained on sociodemographic characteristics, living circumstances, food intake, eating behaviors, mental health and exposure to violence, and on infant's development and anthropometrics measurements.</p> <p>Discussion</p> <p>This project will bring relevant information for a better understanding of the relationship between exposures during pregnancy and how they might affect child development, which can be useful for a better planning of health actions aiming to enhance available resources in primary health care.</p

    Harmful Elements in Estuarine and Coastal Systems

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    Estuaries and coastal zones are dynamic transitional systems which provide many economic and ecological benefits to humans, but also are an ideal habitat for other organisms as well. These areas are becoming contaminated by various anthropogenic activities due to a quick economic growth and urbanization. This chapter explores the sources, chemical speciation, sediment accumulation and removal mechanisms of the harmful elements in estuarine and coastal seawaters. It also describes the effects of toxic elements on aquatic flora and fauna. Finally, the toxic element pollution of the Venice Lagoon, a transitional water body located in the northeastern part of Italy, is discussed as a case study, by presenting the procedures adopted to measure the extent of the pollution, the impacts on organisms and the restoration activities

    Floer cohomology of g-equivariant Lagrangian branes

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    Building on Seidel-Solomon's fundamental work, we define the notion of a g\mathfrak{g}-equivariant Lagrangian brane in an exact symplectic manifold MM where gSH1(M)\mathfrak{g} \subset SH^1(M) is a sub-Lie algebra of the symplectic cohomology of MM. When MM is a (symplectic) mirror to an (algebraic) homogeneous space G/PG/P, homological mirror symmetry predicts that there is an embedding of g\mathfrak{g} in SH1(M)SH^1(M). This allows us to study a mirror theory to classical constructions of Borel-Weil and Bott. We give explicit computations recovering all finite dimensional irreducible representations of sl2\mathfrak{sl}_2 as representations on the Floer cohomology of an sl2\mathfrak{sl}_2-equivariant Lagrangian brane and discuss generalizations to arbitrary finite-dimensional semisimple Lie algebras.Comment: 46 pages, 2 figures. To appear in Compositio Mathematic
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