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Título:
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Cosmological density perturbations in modified gravity theories
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Autores:
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Cruz Dombriz, Álvaro de la ;
Dobado González, Antonio ;
López Maroto, Antonio
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Tipo de documento:
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texto impreso
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Editorial:
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Amer Inst Physics, 2009
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Dimensiones:
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application/pdf
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Nota general:
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info:eu-repo/semantics/openAccess
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Idiomas:
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Palabras clave:
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Estado = Publicado
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Materia = Ciencias: Física
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Tipo = Sección de libro
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Resumen:
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In the context of f(R) theories of gravity, we study the cosmological evolution of scalar perturbations by using a completely general procedure. We find that the exact fourth-order differential equation for the matter density perturbations in the longitudinal gauge, reduces to a second-order equation for sub-Hubble modes. This simplification is compared with the standard (quasi-static) equation used in the literature. We show that for general f(R) functions the quasi-static approximation is not justified. However for those f(R) adequately describing the present phase of accelerated expansion and satisfying local gravity tests, it does give a correct description for the evolution of perturbations.
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En línea:
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https://eprints.ucm.es/id/eprint/21422/1/DobadoAntonio19.pdf
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