2011/09/30 by Gong‐Bo Zhao, Gong-Bo Zhao, Hong Li +6 · 2 citations
Physics and Astronomy · #Astrophysics #Black Holes and Theoretical Physics #COSMIC cancer database #Cosmic microwave background #Cosmology #Cosmology and Gravitation Theories #Dark energy #Equation of state #Galaxies: Formation, Evolution, Phenomena #Galaxy #General relativity #Metric expansion of space #Physics #Quantum gravity #Quantum mechanics #Redshift #Theoretical physics #astro-ph.CO #f(R) gravity #gr-qc #hep-ph
paper · pdf · doi:10.1103/physrevd.85.123546
published as Phys. Rev. D 85, 123546 (2012) · 5 pages, 3 figures; Accepted to Phys. Rev. D
arxiv created 2012/06/05 · openalex publication_date 2012/06/29 · arxiv updated 2012/08/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We test Einstein gravity using cosmological observations of both expansion and structure growth, including the latest data from supernovae (Union2.1), cosmic microwave background (WMAP7), weak lensing (CFHTLS) and the peculiar velocity of galaxies (WiggleZ). We fit modified gravity parameters of the generalized Poisson equations simultaneously with the effective equation of state for the background evolution, exploring the covariances and model dependence. The results show that general relativity is a good fit to the combined data. Using a Pad'e approximant form for the gravity deviations accurately captures the time and scale dependence for theories like f(R) and DGP gravity, and weights high and low redshift probes fairly. For current observations, cosmic growth and expansion can be fit simultaneously with little degradation in accuracy, while removing the possibility of bias from holding one aspect fixed.