Revisiting the universality of (multiple) star formation in present-day
  star formation regions
  Populations of multiple stars inside clustered regions are known to change
through dynamical interactions. The efficiency of binary disruption is thought
to be determined by stellar density. King and collaborators recently
investigated the multiplicity properties in young star forming regions and in
the Galactic field. They concluded that stellar density-dependent modification
of a universal initial binary population (the standard or null hypothesis
model) cannot explain the observations. We re-visit their results, analyzing
the data within the framework of different model assumptions, namely
non-universality without dynamical modification and universality with dynamics.
We illustrate that the standard model does account for all known populations if
regions were significantly denser in the past. Some of the effects of using
present-day cluster properties as proxies for their past values are emphasized
and that the degeneracy between age and density of a star forming region can
not be omitted when interpreting multiplicity data. A new analysis of the
Corona Australis region is performed within the standard model. It is found
that this region is likely as unevolved as Taurus and an initial density of
$\approx190M_{\odot}\;pc^{-3}$ is required to produce the presently observed
binary population, which is close to its present-day density.
