While the Universe is expanding with increasing velocity, the question of what is causing cosmic acceleration remains unsolved. Acceleration seems to act against gravitational attraction, as if a new source of energy, dubbed dark energy, were responsible for it. In addition, neutrino masses are yet to be measured and are degenerate with dark energy evolution.

This PhD proposal is meant to contribute to the Euclid mission, by combining information from galaxy clustering and weak lensing, and integrate it in the Euclid Consortium validated likelihood.

The PhD student will be able to work at the interface between data and theory and concretely collaborate with a large collaboration like the Euclid satellite. Objectives include 1) extending the likelihood software to include early dark energy models 2) contribute to the collaboration effort on comparing theoretical predictions with data and the cross-correlation between galaxy clustering and weak lensing 3) investigate different survey samples and statistics to break the degeneracy between neutrino masses and dark energy evolution.