Year: 2012
Type: article
Abstract: We studied the cosmological constraints on Galileon gravity obtained from observational data of the growth rate of matter density perturbations, the supernovae Ia (SN Ia), the cosmic microwave background (CMB), and baryon acoustic oscillations (BAO). For the same value of the energy density parameter of matter Ωm,0, the growth rate f in Galileon models is enhanced relative to the ΛCDM case, because of an increase in Newton's constant. The smaller the Ωm,0, the more the growth rate is suppressed. Therefore, the best fit value of Ωm,0 in the Galileon model, based only on the growth rate data, is quite small. This is incompatible with the value of Ωm,0 obtained from the combination of SN Ia, CMB, and BAO data. On the other hand, in the ΛCDM model, the values of Ωm,0 obtained from different observational data sets are consistent. In the analysis presented in this paper, we found that the Galileon model is less compatible with observations than the ΛCDM model. This result seems to be qualitatively the same in most of the generalized Galileon models in which Newton's constant is enhanced.
Source: Progress of Theoretical Physics
DOI: 10.1143/ptp.127.1041
Authors: K. Hirano, Z. Komiya, H. Shirai
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2097275738