5,376 research outputs found

    Topological Vertex, String Amplitudes and Spectral Functions of Hyperbolic Geometry

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    We discuss the homological aspects of the connection between quantum string generating function and the formal power series associated to the dimensions of chains and homologies of suitable Lie algebras. Our analysis can be considered as a new straightforward application of the machinery of modular forms and spectral functions (with values in the congruence subgroup of SL(2,Z)SL(2,{\mathbb Z})) to the partition functions of Lagrangian branes, refined vertex and open string partition functions, represented by means of formal power series that encode Lie algebra properties. The common feature in our examples lies in the modular properties of the characters of certain representations of the pertinent affine Lie algebras and in the role of Selberg-type spectral functions of an hyperbolic three-geometry associated with qq-series in the computation of the string amplitudes.Comment: Revised version. References added, results remain unchanged. arXiv admin note: text overlap with arXiv:hep-th/0701156, arXiv:1105.4571, arXiv:1206.0664 by other author

    Scalar and Spinor Particles in the Spacetime of a Domain Wall in String Theory

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    We consider scalar and spinor particles in the spacetime of a domain wall in the context of low energy effective string theories, such as the generalized scalar-tensor gravity theories. This class of theories allows for an arbitrary coupling of the wall and the (gravitational) scalar field. First, we derive the metric of a wall in the weak-field approximation and we show that it depends on the wall's surface energy density and on two post-Newtonian parameters. Then, we solve the Klein-Gordon and the Dirac equations in this spacetime. We obtain the spectrum of energy eigenvalues and the current density in the scalar and spinor cases, respectively. We show that these quantities, except in the case of the energy spectrum for a massless spinor particle, depend on the parameters that characterize the scalar-tensor domain wall.Comment: LATEX file, 21 pages, revised version to appear in Phys. Rev.

    Gerenciamento de resíduos sólidos em comunidades rurais do Estado do Amazonas: estudo de caso na comunidade de Manairão.

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    Este trabalho busca sensibilizar as famílias de agricultores sobre as forma corretas do descarte dos resíduos sem afetar o meio ambiente e sobre as normas da reciclagem e elucidar os problemas sofridos nas comunidades com relação ao lixo; nas comunidades examinadas não havia coletor de lixo, levando o proprietário a uma única solução, jogá-lo na sua propriedade
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