Wave Effects in Double-Plane Lensing
  We discuss the wave optical effects in gravitational lens systems with two
point mass lenses in two different lens planes. We identify and vary parameters
(i.e., lens masses, related distances, and their alignments) related to the
lens system to investigate their effects on the amplification factor. We find
that due to a large number of parameters, it is not possible to make
generalized statements regarding the amplification factor. We conclude by
noting that the best approach to study two-plane and multi-plane lensing is to
study various possible lens systems case by case in order to explore the
possibilities in the parameter space instead of hoping to generalize the
results of a few test cases. We present a preliminary analysis of the parameter
space for a two-lens system here.
