Symmetries of the Universe: The Copernican Principle and its constraints

par Wessel Valkenburg (Universiteit Leiden)

jeudi 23 janv. 2014, 11:00 → 12:00 Europe/Paris

Auditorium (Annecy-le-Vieux)

The Friedmann-Lemaitre metric has a high degree of symmetry, both translational and rotational. The Copernican Principle is the reason why we assume these symmetries. So far, the Copernican Principle had never been tested on cosmological scales. I show the first quantitative test of the Copernican Principle. As a by-product, we find the impact of cosmic structure on our perception of the Friedmann-Lemaître metric becomes. Both the equation of state of Dark Energy and the local expansion rate are more uncertain than we thought, when we take into account that we live at any specific place in the universe that is not exactly homogeneous. Finally, I briefly discuss how other symmetries of space and time could be tested.