Chuck Keeton (University of Chicago)
"Detecting Substructure with Strong Lensing"
The flux ratios between the images in 4-image lenses provide a
powerful test of the smoothness of lens galaxy mass distributions.
Many observed lenses have flux ratios incompatible with smooth models.
Dalal & Kochanek (2002) used a Bayesian analysis to infer that some
2% of the mass in lens galaxies must lie in clumps, which they claim
is a direct detection of substructure in quantities consistent with
CDM and inconsistent with Warm Dark Matter. I will assess the
current state of the data and theory and discuss future prospects on
back to the workshop page