%0 Unpublished work
%T Dispersion in the growth of matter perturbations
%+ Laboratoire de Physique Théorique et Astroparticules (LPTA)
%A Gannouji, Radouane
%A Moraes, Bruno
%A Polarski, David
%Z 8 pages, 5 figures
%Z 09-077
%8 2009-07-02
%D 2009
%Z 0907.0393
%K Cosmology and Extragalactic Astrophysics (astro-ph.CO)
%K General Relativity and Quantum Cosmology (gr-qc)
%Z Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]
%Z Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]
%Z Physics [physics]/General Relativity and Quantum Cosmology [gr-qc]Preprints, Working Papers, ...
%X We consider the linear growth of matter perturbations on low redshifts inmodified gravity Dark Energy (DE) models where G_eff(z,k) is explicitlyscale-dependent. Dispersion in the growth today will only appear for scales ofthe order the critical scale ~ \lambda_{c,0}, the range of the fifth-forcetoday. We generalize the constraint equation satisfied by the parameters\gamma_0(k) and \gamma'_0(k) \equiv \frac{d\gamma(z,k)}{dz}(z=0) to models withG_{eff,0}(k) \ne G. Measurement of \gamma_0(k) and \gamma'_0(k) on severalscales can provide information about \lambda_{c,0}. In the absence ofdispersion when \lambda_{c,0} is large compared to the probed scales,measurement of \gamma_0 and \gamma'_0 provides a consistency check independentof \lambda_{c,0}. This applies in particular to results obtained earlier for aviable f(R) model.
%G English
%L hal-00430269
%U https://hal.science/hal-00430269
%~ IN2P3
%~ LPTA
%~ CNRS
%~ UNIV-MONTP2
%~ UNIV-MONTPELLIER
%~ UM1-UM2