Institution(s): 1. ENS-Lyon
In this talk, I will briefly examine our present understanding of the stellar initial mass function (IMF) and outline an analytical theory of the IMF and of the star formation rate (SFR) based on a gravo-turbulent picture of star formation. I will highlight the concept of turbulent Jeans mass, at the heart of this theory, which differs from the standard thermal Jeans mass, characteristic of the usual purely gravitational star formation picture. I will show that, whereas this theory shows that the IMF should exhibit weak variations under Milky Way like conditions, it naturally predicts a significantly different behaviour under extreme star forming conditions, such as the ones encountered for instance in the progenitors of massive early type galaxies.