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Título:
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Isotropy theorem for cosmological vector fields
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Autores:
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López Maroto, Antonio ;
Ruiz Cembranos, José Alberto ;
Núñez Jareño, Santos José ;
Hallabrin, C.
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Tipo de documento:
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texto impreso
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Editorial:
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American Physical Society, 2012-07-10
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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 = Artículo
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Resumen:
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We consider homogeneous Abelian vector fields in an expanding universe. We find a mechanical analogy in which the system behaves as a particle moving in three dimensions under the action of a central potential. In the case of bounded and rapid evolution compared to the rate of expansion, we show-by making use of the virial theorem-that for an arbitrary potential and polarization pattern, the average energy-momentum tensor is always diagonal and isotropic despite the intrinsic anisotropic evolution of the vector field. For simple power law potentials of the form V = lambda(A(mu)A(mu))(n), the average equation of state is found to be w = (n - 1)/(n + 1). This implies that vector coherent oscillations could act as natural dark matter or dark energy candidates. Finally, we show that under very general conditions, the average energy-momentum tensor of a rapidly evolving bounded vector field in any background geometry is always isotropic and has the perfect fluid form for any locally inertial observer.
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En línea:
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https://eprints.ucm.es/id/eprint/25826/1/MarotoAL04libre.pdf
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