2,159 research outputs found

    Renormalization group in super-renormalizable quantum gravity

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    One of the main advantages of super-renormalizable higher derivative quantum gravity models is the possibility to derive exact beta functions, by making perturbative one-loop calculations. We perform such a calculation for the Newton constant by using the Barvinsky-Vilkovisky trace technology. The result is well-defined in a large class of models of gravity in the sense that the renormalization group beta functions do not depend on the gauge-fixing condition. Finally, we discuss the possibility to apply the results to a large class of nonlocal gravitational theories which are free of massive ghost-like states at the tree-level.Comment: 21 pages, journal version, improved and with two new appendice

    Unitary issues in some higher derivative field theories

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    We analyze the unitarity properties of higher derivative quantum field theories which are free of ghosts and ultraviolet singularities. We point out that in spite of the absence of ghosts most of these theories are not unitary. This result confirms the difficulties of finding a consistent quantum field theory of quantum gravity

    One-loop effective action in quantum gravitation

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    We present the formalism of computing one-loop effective action for Quantum Gravitation using non-local heat kernel methods. We found agreement with previous old results. In main part of my presentation I considered the system of E-H gravitation and scalar fields. We were able to derive non-local quantum effective action up to the second order in heat kernel generalized curvatures. By going to flat spacetime expressions for gravitational form factors are possible to construct and compare with the results from effective field theory for gravity

    Educação ambiental e a experiência da Embrapa Florestas.

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    A educação ambiental tornou-se uma prática indispensável em todas as empresas e instituições públicas e privadas nas esferas municipal, estadual e federal. Este trabalho objetivou apresentar a experiência do Programa de Educação Ambiental da Embrapa Florestas (PREA), no período de 2001 a 2006. Durante seis anos de atividades, o PREA ministrou inúmeros cursos e palestras, conduziu grupos em trilhas ecológicas, participou de eventos, organizou encontros referentes a meio ambiente, realizou diagnósticos ambientais, estabeleceu parcerias de cooperação técnica com vários órgãos e empresas e publicou material didático sobre educação ambiental. Os resultados indicaram que a Embrapa Florestas, juntamente com seus parceiros, desenvolveu e aplicou métodos eficientes de educação ambiental e os transmitiu para um número significativo de pessoas.bitstream/CNPF-2009-09/41611/1/BPD29_CD.pd

    Educação ambiental na trilha ecológica da Embrapa Florestas

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    bitstream/CNPF-2009-09/42612/1/Doc147.pdf1 CD-ROM
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