Testing General Relativity on cosmological scales

[摘要] In order to test the validity of General Relativity (GR) on cosmological scales, it has been proposed that measuring the so called growth index, γ, could provide an efficient way to discriminate between scalar field dark energy models which admit to general relativity and modified gravity models. Using the clustering properties of the Luminus Red Galaxies and the growth data we perform a standard χ2-minimization procedure between theoretical expectations and data, followed by a joint likelihood analysis and we find a value of γ = 0.56 ± 0.05, perfectly consistent with the expectations of the ΛCDM model, and Ωm0= 0.29 ± 0.02, in very good agreement with the latest Planck results. Our analysis provides significantly more stringent growth index constraints with respect to previous studies, as indicated by the fact that the corresponding uncertainty is only ∼ 0.09γ.

[发布机构] Research Center for Astronomy and Applied Mathematics of the Academy of Athens, Greece^1

[效力级别] 数学

[关键词] Clustering properties;Cosmological scale;Dark energy;General Relativity;Gravity model;Growth indexes;Joint likelihoods;Scalar fields