13,427 research outputs found
Topological gravity localization on a delta-function like Brane
Besides the String Theory context, the quantum General Relativity can be
studied by the use of constrained topological field theories. In the celebrated
Plebanski formalism, the constraints connecting topological field theories and
gravity are imposed in space-times with trivial topology. In the braneworld
context there are two distinct regions of the space-time, namely, the bulk and
the braneworld volume. In this work we show how to construct topological
gravity in a scenario containing one extra dimension and a delta-function like
3-brane which naturally emerges from a spontaneously broken discrete symmetry.
Starting from a D=5 theory we obtain the action for General Relativity in the
Palatini form in the bulk as well as in the braneworld volume. This result is
important for future insights about quantum gravity in brane scenarios.Comment: 4 page
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Eosinophilic dermatosis of hematologic malignancy: a case report
Eosinophilic dermatosis of hematologic malignancy (EDHM) is a dermatosis characterized by tissue eosinophilia that has been previously reported as insect bite-like reaction. It is a rare condition with a wide variety of clinical presentations ranging from papules, nodules, or blisters that simulate arthropod bites, to the formation of plaques of differing sizes. We report a case of eosinophilic dermatosis of hematologic malignancy in a patient with a hematoproliferative disorder
Método exploratório de indicadores de adoção de variedades melhoradas.
Neste boletim de pesquisa, é proposto um método exploratório para calcular os indicadores de adoção de variedades melhoradas, especialmente recomendado em caso de ausência de séries históricas acerca do processo de adoção. A quase ausência desses dados constitui o principal obstáculo à realização de estudos de adoção de variedades melhoradas na Embrapa. Portanto, o método proposto contribui ao tornar possível estudo dessa natureza a partir da coleta, em campo, de um conjunto mínimo de dados acerca do processo de adoção de variedades melhoradas. O método é composto por 12 indicadores de adoção, agrupados em três categorias principais: alcance, velocidade e eficiência. Embora o método proposto possa ser utilizado para lavouras temporárias e permanentes, a título de exemplo, e unicamente com este propósito, são calculados os indicadores de adoção de duas variedades de mandioca lançadas pela Embrapa: BRS Formosa e BRS Kiriris. Os indicadores foram elaborados por ocasião da submissão do projeto ?Impacto da pesquisa participativa do melhoramento genético da mandioca no bioma caatinga?, ao macroprograma 4 da Embrapa, sob a liderança da Embrapa Mandioca e Fruticultura.bitstream/item/100889/1/boletim-59-Finalizado-novamente-alterado.pd
A method for evaluating models that use galaxy rotation curves to derive the density profiles
There are some approaches, either based on General Relativity (GR) or
modified gravity, that use galaxy rotation curves to derive the matter density
of the corresponding galaxy, and this procedure would either indicate a partial
or a complete elimination of dark matter in galaxies. Here we review these
approaches, clarify the difficulties on this inverted procedure, present a
method for evaluating them, and use it to test two specific approaches that are
based on GR: the Cooperstock-Tieu (CT) and the Balasin-Grumiller (BG)
approaches. Using this new method, we find that neither of the tested
approaches can satisfactorily fit the observational data without dark matter.
The CT approach results can be significantly improved if some dark matter is
considered, while for the BG approach no usual dark matter halo can improve its
results.Comment: 11 pages, 2 figures, 4 tables. v2: diverse text improvements, no
changes in the conclusions. Version accepted in MNRA
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