Speaker
Description
The accelerated expansion of the Universe is canonically attributed to the Dark Energy (DE), encapsulated in the Lambda factor in the Einstein field equations of gravity, but its nature is still not understood. While observations supply strong evidence in favor of the standard model of cosmology Lambda-CDM, a plethora of different modified gravity models (MG) can still arise and describe gravity and DE in another way than a Lambda-constant. In our work, we exploit the Effective Field Theory (EFT) framework which allows us to describe gravity and DE in a general way, encompassing single-field models. The strength of this approach is that we can describe not only general features of gravity but also recover model-dependent results through a mapping procedure. Upon this theoretical setting, we combine CMB and galaxy-clustering observables to discriminate between Lambda-CDM and MG/DE models. One of our main aims is to specifically assess the constraining power of cross-correlations between different probes from wide galaxy surveys, like Euclid, and the high sensitivity maps of the microwave sky delivered by Planck.
