Abstract
Dark energy represents one of the greatest mysteries of current science : is it a cosmological constant, an exotic fluid or the manifestation of a modification of the laws of gravity on a large scale ? To answer this crucial question, we need both to develop theories exploring different scenarios within the framework of general relativity and beyond, and to carry out deep surveys of galaxies, whose distribution is sensitive to the nature of dark energy.
But this is unfortunately not enough. It is, in fact, crucial to build a robust bridge between theories and observations. At present, the most accurate tool at our disposal is numerical simulation. In this seminar, I will present the fundamental contribution of numerical simulations to the problem of the nature of dark energy.
Using models of the formation of the Universe's great structures, scientists are carrying out experiments " in-silico ", varying the properties of dark energy and studying their consequences on the distribution of galaxies. By exploring hundreds of simulated universes corresponding to as many models of dark energy, and comparing them with observations, cosmologists look for those that are compatible with our own. This approach provides valuable clues in our quest to understand the nature of dark energy.
