2007/10/11 by David Polarski, Radouane Gannouji · 10 citations
Mathematics · Physics and Astronomy · #Advanced Differential Equations and Dynamical Systems #Cosmology and Gravitation Theories #Mathematical Dynamics and Fractals #astro-ph #gr-qc
paper · pdf · doi:10.1016/j.physletb.2008.01.032
published as Phys.Lett.B660:439-443,2008 · 8 pages, 8 figures. Results unchanged; clarifying sentence added; one reference added
arxiv created 2007/10/11 · openalex publication_date 2008/01/31 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We consider the linear growth of matter perturbations in various dark energy (DE) models. We show the existence of a constraint valid at z=0 between the background and dark energy parameters and the matter perturbations growth parameters. For ΛCDM γ0′≡dγdz|0 lies in a very narrow interval −0.0195⩽γ0′⩽−0.0157 for 0.2⩽Ωm,0⩽0.35. Models with a constant equation of state inside General Relativity (GR) are characterized by a quasi-constant γ0′, for Ωm,0=0.3 for example we have γ0′≈−0.02 while γ0 can have a nonnegligible variation. A smoothly varying equation of state inside GR does not produce either |γ0′|>0.02. A measurement of γ(z) on small redshifts could help discriminate between various DE models even if their γ0 is close, a possibility interesting for DE models outside GR for which a significant γ0′ can be obtained.