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Evidence for interacting dark energy from BOSS

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Autor(es):
Ferreira, Elisa G. M. ; Quintin, Jerome ; Costa, Andre A. ; Abdalla, E. ; Wang, Bin
Número total de Autores: 5
Tipo de documento: Artigo Científico
Fonte: PHYSICAL REVIEW D; v. 95, n. 4, p. 9-pg., 2017-02-21.
Resumo

The result presented by the BOSS-SDSS Collaboration measuring the baryon acoustic oscillations of the Lyman-alpha forest from high-redshift quasars indicates a 2.5 sigma departure from the standard Lambda-cold-dark-matter model. This is the first time that the evolution of dark energy at high redshifts has been measured, and the current results cannot be explained by simple generalizations of the cosmological constant. We show here that a simple phenomenological interaction in the dark sector provides a good explanation for this deviation, naturally accommodating the Hubble parameter obtained by BOSS, Hd(z = 2.34) = 222 +/- 7 km s(-1) Mpc(-1). By performing a global fit of the parameters with the inclusion of this new data set together with the Planck data for the interacting model, we are able to show that some interacting models have constraints for Hd(2.34) and D-A(2.34) that are compatible with the ones obtained by the BOSS Collaboration, showing a better concordance than.CDM. We also show that the interacting models that have a small positive coupling constant, which helps alleviate the coincidence problem, are compatible with the cosmological observations. Adding the likelihood of these new baryon acoustic oscillations data shows an improvement in the global fit, although it is not statistically significant. The coupling constant could not be fully constrained by the data sets used, but the dark energy equation of state shows a slight preference for a value different from a cosmological constant. (AU)

Processo FAPESP: 13/26496-2 - Testando modelos de interação entre matéria e energia escuras
Beneficiário:André Alencar da Costa
Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
Processo FAPESP: 09/54006-4 - Um cluster de computadores para o Departamento de Astronomia do IAG-USP e para o Núcleo de Astrofísica da UNICSUL
Beneficiário:Elisabete Maria de Gouveia Dal Pino
Modalidade de apoio: Auxílio à Pesquisa - Programa Equipamentos Multiusuários