Modes of star formation from Herschel
  We summarize some of the results obtained from Herschel surveys of the nearby
star forming regions and the Galactic plane. We show that in the nearby star
forming regions the starless core spatial surface density distribution is very
similar to that of the young stellar objects. This, taken together with the
similarity between the core mass function and the initial mass function for
stars and the relationship between the amount of dense gas and star formation
rate, suggest that the cloud fragmentation process defines the global outcome
of star formation. This "simple" view of star formation may not hold on all
scales. In particular dynamical interactions are expected to become important
at the conditions required to form young massive clusters. We describe the
successes of a simple criterion to identify young massive cluster precursors in
our Galaxy based on (sub-)millimetre wide area surveys. We further show that in
the location of our Galaxy where the best candidate for a precursor of a young
massive cluster is found, the "simple" scaling relationship between dense gas
and star formation rate appear to break down. We suggest that in regions where
the conditions approach those of the central molecular zone of our Galaxy it
may be necessary to revise the scaling laws for star formation.
