Interpreting the strongly lensed supernova iPTF16geu: time delay
  predictions, microlensing, and lensing rates
  We present predictions for time delays between multiple images of the
gravitationally lensed supernova, iPTF16geu, which was recently discovered from
the intermediate Palomar Transient Factory (iPTF). As the supernova is of Type
Ia where the intrinsic luminosity is usually well-known, accurately measured
time delays of the multiple images could provide tight constraints on the
Hubble constant. According to our lens mass models constrained by the {\it
Hubble Space Telescope} F814W image, we expect the maximum relative time delay
to be less than a day, which is consistent with the maximum of 100 hours
reported by Goobar et al. but places a stringent upper limit. Furthermore, the
fluxes of most of the supernova images depart from expected values suggesting
that they are affected by microlensing. The microlensing timescales are small
enough that they may pose significant problems to measure the time delays
reliably. Our lensing rate calculation indicates that the occurrence of a
lensed SN in iPTF is likely. However, the observed total magnification of
iPTF16geu is larger than expected, given its redshift. This may be a further
indication of ongoing microlensing in this system.
