%0 Journal Article
%T Chameleon dark energy models with characteristic signatures
%+ Laboratoire de Physique Théorique et Astroparticules (LPTA)
%A Gannouji, Radouane
%A Moraes, Bruno
%A Mota, David F.
%A Polarski, David
%A Tsujikawa, Shinji
%A Winther, Hans A.
%Z 16 pages, 8 figures Journal: Phys.Rev.D82:124006,2010
%< avec comité de lecture
%Z L2C:10-031
%@ 1550-7998
%J Physical Review D
%I American Physical Society
%P 124006
%8 2010
%D 2010
%Z 1010.3769
%R 10.1103/PhysRevD.82.124006
%Z Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]
%Z Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]
%Z Physics [physics]/General Relativity and Quantum Cosmology [gr-qc]
%Z Physics [physics]/High Energy Physics - Phenomenology [hep-ph]
%Z Physics [physics]/High Energy Physics - Theory [hep-th]Journal articles
%X In chameleon dark energy models, local gravity constraints tend to rule out parameters in which observable cosmological signatures can be found. We study viable chameleon potentials consistent with a number of recent observational and experimental bounds. A novel chameleon field potential, motivated by f(R) gravity, is constructed where observable cosmological signatures are present both at the background evolution and in the growth-rate of the perturbations. We study the evolution of matter density perturbations on low redshifts for this potential and show that the growth index today gamma_0 can have significant dispersion on scales relevant for large scale structures. The values of gamma_0 can be even smaller than 0.2 with large variations of gamma on very low redshifts for the model parameters constrained by local gravity tests. This gives a possibility to clearly distinguish these chameleon models from the Lambda-Cold-Dark-Matter model in future high-precision observations.
%G English
%L hal-00632706
%U https://hal.science/hal-00632706
%~ IN2P3
%~ LPTA
%~ CNRS
%~ UNIV-MONTP2
%~ UNIV-MONTPELLIER
%~ UM1-UM2