COT3 - Inhomogeneous Cosmology |
Speaker_ |
Larena, Julien |
Co-autors |
Thomas Buchert and Jean-Michel Alimi |
Talk _ |
Reinterpreting the quintessential dark energy through backreaction: the minimally coupled morphon field. |
Abstract _ |
In the context of averaged cosmologies, the effective equations can be written in the form of "regional" Friedmannian equations with additional sources arising from the so-called backreactions of inhoimogeneities. We propose a mean field description of these backreactions in terms of a regionally homogeneous scalar field: this provides a physical motivation to the phenomenological scalar fields generically called quintessence fields. We explicitly reconstruct the potential of the scalar field for the one-parameter family of scaling solutions to the backreaction problem, showing that it entails most of the standard scalar fields including e.g. standard and phantom quintessences. We then explore the solution space showing that the Einstein-de Sitter scenario appears as a saddle point naturally unstable in the direction of accelerating models. |