Detection of IMBHs from microlensing in globular clusters
  Globular clusters have been alternatively predicted to host intermediate-mass
black holes (IMBHs) or nearly impossible to form and retain them in their
centres. Over the last decade enough theoretical and observational evidence
have accumulated to believe that many galactic globular clusters may host IMBHs
in their centres, just like galaxies do. The well-established correlations
between the supermassive black holes and their host galaxies do suggest that,
in extrapolation, globular clusters (GCs) follow the same relations. Most of
the attempts in search of the central black holes (BHs) are not direct and
present enormous observational difficulties due to the crowding of stars in the
GC cores. Here we propose a new method of detection of the central BH -- the
microlensing of the cluster stars by the central BH. If the core of the cluster
is resolved, the direct determination of the lensing curve and lensing system
parameters are possible; if unresolved, the differential imaging technique can
be applied. We calculate the optical depth to central BH microlensing for a
selected list of Galactic GCs and estimate the average time duration of the
events. We present the observational strategy and discuss the detectability of
microlensing events using a 2-m class telescope.
