Investigating mass segregation process in globular clusters with Blue
  Straggler Stars: the impact of dark remnants
  We present the results of a set of N-body simulations aimed at exploring how
the process of mass segregation (as traced by the spatial distribution of blue
straggler stars, BSSs) is affected by the presence of a population of heavy
dark remnants (as neutron stars and black holes). To this end, clusters
characterized by different initial concentrations and different fractions of
dark remnants have been modeled. We find that an increasing fraction of
stellar-mass black holes significantly delays the mass segregation of BSSs and
the visible stellar component. In order to trace the evolution of BSS
segregation, we introduce a new parameter ($A^+$) that can be easily measured
when the cumulative radial distribution of these stars and a reference
population are available. Our simulations show that $A^+$ might also be used as
an approximate indicator of the time remaining to the core collapse of the
visible component.
