Studying light propagation in a locally homogeneous universe through an extended Dyer-Roeder approach

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dc.contributor.author Lima, José Ademar Sales de
dc.contributor.author Busti, Vinicius Consolini
dc.contributor.author Santos, Rose Clívia [UNIFESP]
dc.date.accessioned 2016-01-24T14:35:26Z
dc.date.available 2016-01-24T14:35:26Z
dc.date.issued 2014-03-04
dc.identifier http://dx.doi.org/10.1103/PhysRevD.89.067301
dc.identifier.citation Physical Review D. College Pk: Amer Physical Soc, v. 89, n. 6, 5 p., 2014.
dc.identifier.issn 1550-7998
dc.identifier.uri http://repositorio.unifesp.br/handle/11600/37541
dc.description.abstract Light is affected by local inhomogeneities in its propagation, which may alter distances and so cosmological parameter estimation. in the era of precision cosmology, the presence of inhomogeneities may induce systematic errors if not properly accounted. in this vein, a new interpretation of the conventional Dyer-Roeder (DR) approach by allowing light received from distant sources to travel in regions denser than average is proposed. It is argued that the existence of a distribution of small and moderate cosmic voids (or black regions) implies that its matter content was redistributed to the homogeneous and clustered matter components with the former becoming denser than the cosmic average in the absence of voids. Phenomenologically, this means that the DR smoothness parameter (denoted here by alpha(E)) can be greater than unity, and, therefore, all previous analyses constraining it should be rediscussed with a free upper limit. Accordingly, by performing a statistical analysis involving 557 type Ia supernovae (SNe Ia) from Union2 compilation data in a flat ACDM model, we obtain for the extended parameter alpha(E) = 1.26(-0.54)(+0.68) (1 sigma). the effects of aE are also analyzed for generic ACDM models and flat XCDM cosmologies. for both models, we find that a value of aE greater than unity is able to harmonize SNe Ia and cosmic microwave background observations thereby alleviating the well-known tension between low and high redshift data. Finally, a simple toy model based on the existence of cosmic voids is proposed in order to justify why alpha(E) can be greater than unity as required by supernovae data. en
dc.description.sponsorship Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.description.sponsorship Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
dc.description.sponsorship INCT-Astrofisica
dc.format.extent 5
dc.language.iso eng
dc.publisher Amer Physical Soc
dc.relation.ispartof Physical Review D
dc.rights Acesso restrito
dc.title Studying light propagation in a locally homogeneous universe through an extended Dyer-Roeder approach en
dc.type Artigo
dc.rights.license http://publish.aps.org/authors/transfer-of-copyright-agreement
dc.contributor.institution Universidade de São Paulo (USP)
dc.contributor.institution Universidade Federal de São Paulo (UNIFESP)
dc.description.affiliation Univ São Paulo, Dept Astron, BR-05508900 São Paulo, Brazil
dc.description.affiliation Universidade Federal de São Paulo UNIFESP, Dept Ciencias Exatas & Terra, BR-09972270 São Paulo, Brazil
dc.description.affiliationUnifesp Universidade Federal de São Paulo UNIFESP, Dept Ciencias Exatas & Terra, BR-09972270 São Paulo, Brazil
dc.identifier.doi 10.1103/PhysRevD.89.067301
dc.description.source Web of Science
dc.identifier.wos WOS:000333106800008



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