ATTENZIONE ALL'ORARIO: ORE 15:00
One of the main and still controversial question of modern cosmology is how and when galaxies form and in particular massive early-type galaxies and spheroids. It is still uncertain how the mass assembly history depends on the mass and on the galaxy types and how the bimodality seen in the local Universe in galaxies properties (colour, morphology and spectral features) evolves and when was built up. There is growing evidence that luminous and rather massive old galaxies may have been quite common already at z~1 and up to z~2. Recent results show indeed that early-type massive galaxies should have formed their stars and assembled their mass at relatively high redshift. Here I present recent results on the cosmic evolution of the Galaxy Stellar Mass Function (MF) as well as the contribution of different galaxy populations, based mainly on zCOSMOS spectroscopic survey.