SPEAKER: Federico Piazza (CPT, Aix-Marseille)
ABSTRACT: I will present recent and ongoing works that aim at a unifying description of dark energy and modified gravity models containing a scalar degree of freedom in addition to general relativity. Such an effective field theory approach allows, on the one hand, a transparent analysis of the possible theoretical mechanisms at the basis of cosmic acceleration; moreover, it provides a useful set of parameters that can be efficiently constrained with observations. I will discuss the present observational constraints on the parameters of the theory based on cosmological probes (such as the growth rate of cosmic structures) and also astrophysical/galactic ones. I will show some generic features that such models share independently of the choice of their free parameters.