CosmoStat Calendar

Title: A new probe of dark energy

Speaker: Vasiliki Pavlidou, University of Crete and Institute of Astrophysics - FORTH

Abstract:

In the currently favored cosmological model, the energy density of the Universe is dominated by a field of unknown nature - dark energy - acting anti-gravitationally. All our current evidence for the existence of dark energy, whether in the form of a cosmological constant or an evolving field, is indirect and global (based on the effect of dark energy on the Universe as a whole). I will discuss a novel path towards probing dark energy, using galaxy clusters on their largest non-expanding scales. I will show how measurements of the mass enclosed by the boundary between galaxy clusters and the expanding Universe can directly and uniquely probe dark energy *locally*: on scales much smaller than the observable Universe, and at the present cosmic time.