SMILE: Search for MIlli-LEnses
  Dark Matter (DM) halos with masses below $\sim10^{8}$ $M_{\odot}$, which
would help to discriminate between DM models, may be detected through their
gravitational effect on distant sources. The same applies to primordial black
holes, considered as an alternative scenario to DM particle models. However,
there is still no evidence for the existence of such objects. With the aim of
finding compact objects in the mass range $\sim$ 10$^{6}$ --
10$^{9}$$M_{\odot}$, we search for strong gravitational lenses on milli
(mas)-arcseconds scales (< 150 mas). For our search, we used the Astrogeo VLBI
FITS image database -- the largest publicly available database, containing
multi-frequency VLBI data of 13828 individual sources. We used the citizen
science approach to visually inspect all sources in all available frequencies
in search for images with multiple compact components on mas-scales. At the
final stage, sources were excluded based on the surface brightness preservation
criterion. We obtained a sample of 40 sources that passed all steps and
therefore are judged to be milli-arcsecond lens candidates. These sources are
currently followed-up with on-going European VLBI Network (EVN) observations at
5 and 22 GHz. Based on spectral index measurements, we suggest that two of our
candidates have a higher probability to be associated with gravitational
lenses.
