Galaxy formation hydrodynamics: From cosmic flows to star-forming clouds
  Major progress has been made over the last few years in understanding
hydrodynamical processes on cosmological scales, in particular how galaxies get
their baryons. There is increasing recognition that a large part of the baryons
accrete smoothly onto galaxies, and that internal evolution processes play a
major role in shaping galaxies - mergers are not necessarily the dominant
process. However, predictions from the various assembly mechanisms are still in
large disagreement with the observed properties of galaxies in the nearby
Universe. Small-scale processes have a major impact on the global evolution of
galaxies over a Hubble time and the usual sub-grid models account for them in a
far too uncertain way. Understanding when, where and at which rate galaxies
formed their stars becomes crucial to understand the formation of galaxy
populations. I discuss recent improvements and current limitations in
"resolved" modelling of star formation, aiming at explicitely capturing
star-forming instabilities, in cosmological and galaxy-sized simulations. Such
models need to develop three-dimensional turbulence in the ISM, which requires
parsec-scale resolution at redshift zero.
