Rethinking Globular Cluster Formation
  This paper is aimed at emphasizing some of the main hints, constraints and
difficulties we currently have in trying to understand how globular clusters
formed, along with their multiple stellar generations, an issue that must be
regarded as intimately connected to the formation process itself. Thus, the
topics that are addressed include i) the required mass of the progenitor, ii)
how to form new stars in an environment already crowded by a previous stellar
generation, iii) how photometry and spectroscopy appear to suggest different
formation processes for second generation stars, iv) whether dilution with
pristine material may (or may not) be necessary for the formation of second
generations, v) why the few clusters with multiple iron abundances are after
all not so different from those that are homogeneous, and finally vi) why
special environmental conditions may not be necessary for the formation of
globular clusters with multiple stellar generations.
