%0 Journal Article
%T On the growth of linear perturbations
%+ Laboratoire de Physique Théorique et Astroparticules (LPTA)
%A Polarski, D.
%A Gannouji, R.
%Z 8 pages, 8 figures
%< avec comité de lecture
%Z pta/07-49
%@ 0370-2693
%J Physics Letters B
%I Elsevier
%V 660
%P 439-443
%8 2007
%D 2007
%Z 0710.1510
%R 10.1016/j.physletb.2008.01.032
%Z 04.62.+v; 98.80.Cq
%Z Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]
%Z Sciences of the Universe [physics]/Astrophysics [astro-ph]Journal articles
%X 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 $\Lambda$CDM $\gamma'_0\equiv \frac{d\gamma}{dz}_0$ lies in a very narrow interval $-0.0195 \le \gamma'_0 \le -0.0157$ for $0.2 \le \Omega_{m,0}\le 0.35$. Models with a constant equation of state inside General Relativity (GR) are characterized by a quasi-constant $\gamma'_0$, for $\Omega_{m,0}=0.3$ for example we have $\gamma'_0\approx -0.02$ while $\gamma_0$ can have a nonnegligible variation. A smoothly varying equation of state inside GR does not produce either $|\gamma'_0|>0.02$. A measurement of $\gamma(z)$ on small redshifts could help discriminate between various DE models even if their $\gamma_0$ is close, a possibility interesting for DE models outside GR for which a significant $\gamma'_0$ can be obtained.
%G English
%L in2p3-00179750
%U https://hal.in2p3.fr/in2p3-00179750
%~ IN2P3
%~ LPTA
%~ CNRS
%~ UNIV-MONTP2
%~ UNIV-MONTPELLIER
%~ UM1-UM2