Abstract

Recent improvements of observational and numerical techniques have permitted to unveil the wide diversity of star forming clouds, in the Milky Way but also in other nearby galaxies. The variety in the morphology and dynamics of these clouds, as a function of their galactic environment, strongly suggests a complex interplay between global (kpc-scale) and local (pc-scale) processes, that remains to be fully understood. The coupling between large-scale structures, turbulence, self-gravity, magnetic fields and feedback makes this problem one of the most challenging of modern astrophysics. Using a set of (sub)parsec-resolution simulations of galaxies including local spirals, mergers and high redshift disks, I will illustrate the diversity of star formation in simulations and compare to what is observed. I will emphasise the role of the variation of parameters within a single disk galaxy and then explore the differences from galaxy to galaxy. I will propose a new theory on the triggering of star formation in local mergers and discuss its implications on the non-universality of the stellar initial mass function. I will conclude by drawing a connection to galaxies at higher redshifts.