The innocuousness of adiabatic instabilities in coupled scalar field-dark matter models

Abstract

Non-minimally coupled scalar field models suffer of unstable growing modes at the linear perturbation level. The nature of these instabilities depends on the dynamical state of the scalar field. In particular in systems which admit adiabatic solutions, large scale instabilities are suppressed by the slow-roll dynamics of the field. Here we review these results and present a preliminary likelihood data analysis suggesting that along adiabatic solutions coupled models with coupling of order of gravitational strength can provide viable cosmological scenarios satisfying constraints from SN Ia, CMB and large scale structure data.

6 pages, 4 figures; to be published in the AIP proceedings of the 'Invisible Universe International Conference', UNESCO-Paris, June 29-July 3, 2009

Cited by in corpus (2)

• Coupled three-form dark energy
• How CMB and large-scale structure constrain chameleon interacting dark energy