The Two LIGO/Virgo Binary Black Hole Mergers on 2019 August 28 Were Not
  Strongly Lensed
  The LIGO/Virgo gravitational wave events S190828j and S190828l were detected
only 21 minutes apart, from nearby regions of sky, and with the same source
classifications (binary black hole mergers). It is therefore natural to
speculate that the two signals are actually strongly lensed images of the same
merger. However, an estimate of the separation of the (unknown) positions of
the two events requires them to be >10 deg apart, much wider than the
arcsecond-scale separations that usually arise in extragalactic lensing. The
large separation is much more consistent with two independent, unrelated events
that occurred close in time by chance. We quantify the overlap between
simulated pairs of lensed events, and use frequentist hypothesis testing to
reject S190828j/l as a lensed pair at 99.8% confidence.
