Challenging Lambda with Euclid and beyond
PT-CERN Call 2022/1
Universidade do Porto
Centro de Astrofísica da Universidade do Porto
The growing amount of observational evidence for the recent acceleration of the universe unambiguously demonstrates that canonical theories of cosmology and particle physics are incomplete (if not incorrect) and that new physics is out there, waiting to be discovered. The most fundamental task for the next generation of astrophysical facilities is therefore to search for, identify and ultimately characterise this new physics. The acceleration is seemingly due to a dark component whose low-redshift gravitational behaviour is very similar to that of a cosmological constant. However, currently available data provides very little information about the high-redshift behaviour of this dark sector or its interactions with the rest of the degrees of freedom in the model. It is becoming increasingly clear that tackling the dark energy enigma will entail significantly extending the redshift range where its behaviour can be accurately mapped. A new generation of ESA and ESO facilities, such as Euclid, the ELT, and the SKAO have dark energy characterization as a key science driver, and in addition to significantly increasing the range and sensitivity of current observational probes will allow for entirely new tests. The goal of this thesis will be to carry out a systematic exploration of the landscape of physically viable dark energy paradigms and provide optimal discriminating observational tests. The work will initially focus on Euclid (whose launch is fast approaching) and will gradually broaden to explore synergies and probe combination with the SKAO and ANDES. The work will be done in the framework of the Euclid TWG, and the student will be a member of Euclid. This is a fundamental physics research project, using cutting-edge astrophysical facilities to probe the fundamental constituents and laws of the universe at length, time and energy scales that complement those that can be probed at cutting-edge particle accelerators.