A fast algorithm for simulating light curves of stars at extreme
  magnification affected by microlensing
  We present a fast algorithm to produce light curves of distant stars
undergoing microlensing near critical curves. The need of these type of
algorithms is motivated by recent observations of microlensing events of
distant stars at high redshift and at extreme magnification factors. The
algorithm relies on a low-resolution computation of the deflection field due to
an ensemble of microlenses near critical curves, and takes advantage of the
slowly varying nature of the deflection field to infer the magnification of the
unresolved images.
