Comment on “Constraining the smoothness parameter and dark energy using observationalH(z) data"
Year: 2011
Type: article
Abstract: We discuss a recent analysis by Yu et al. [ RAA 11, 125 (2011) ] about constraints on the smoothness parameter α and dark energy models using observational H ( z ) data. It is argued here that their procedure is conceptually inconsistent with the basic assumptions underlying the adopted Dyer-Roeder approach. In order to properly quantify the influence of the H ( z ) data on the smoothness parameter α, a χ 2 -test involving a sample of type Ia supernovae and H ( z ) data in the context of a flat ΛCDM model is reanalyzed. This result is confronted with an earlier approach discussed by Santos et al. (2008) without H ( z ) data. In the (Ω m , α) plane, it is found that such parameters are now restricted to be in the intervals 0.66 ≤ α ≤ 1.0 and 0.27 ≤ Ω m ≤ 0.37 within the 95.4% confidence level (2σ), and, therefore, are fully compatible with the homogeneous case. The basic conclusion is that a joint analysis involving H ( z ) data can indirectly improve our knowledge about the influence of the inhomogeneities. However, this happens only because the H ( z ) data provide tighter constraints on the matter density parameter Ω m .
Authors: V. C Busti, R. C Santos
Institutions: Universidade de São Paulo, Universidade Federal de São Paulo
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2157739433