Detailed dark matter maps of galaxy cluster substructure and direct
  comparison to simulations
  Images from the next generation of telescopes will enable strikingly detailed
reconstruction of the dark matter distributions in galaxy cluster cores using
strong gravitational lensing analysis. This will provide a key test of
Lambda-CDM cosmology on cluster scales where tensions currently exist. Observed
dark matter distributions will be compared directly to those realized in
simulations, forgoing any assumptions about light tracing mass. The required
observations are deep, multicolor, and high-resolution, ideally supplemented
with spectra of faint objects. ACS onboard HST is capable of obtaining images
of sufficient quality, but for prohibitive integration times. The next
generation of telescopes promises to efficiently yield the required images. An
analysis method capable of processing the expected large numbers of multiple
images has been developed (see below). The full range of constraints possible
from analyzing these detailed mass maps is a matter of ongoing investigation.
