SESZIONE DI TORINO
The nature of dark energy, the fluid leading to the accelerated expansion observed in the Universe, is one of the main challenges of contemporary cosmology. As any great scientific open question, its ramifications extend from the empirical determination of the parameters of the equation of state, through its solid theoretical formulation. In this presentation, we describe a project that elaborates upon a classical cosmological test to determine the dark energy equation of state. Deep observations (z < 1.5) of a cluster sample over 1000 square degree yields the cluster abundance as a function of redshift, a relation that can be calculated using self-calibration techniques combined with few independent mass estimates. We demonstrate that this cluster abundance measurement can put strong constraints on the dark energy equation of state. ===================

DATA: 12-11-2008