Princeton University/Institute for Advanced Study Early Universe/Cosmology Lunch Discussion - TITLE ADDED

Clusters of galaxies gravitationally lens the cosmic microwave background (CMB) and thereby generate a distinct signal in the CMB on arcminute scales. Measurements of this effect can be used to constrain the masses of galaxy clusters using CMB data alone. I'll present a measurement of lensing of the CMB by galaxy clusters using data from the South Pole Telescope's Sunyaev-Zel'dovich (SZ) Survey. We find that the cluster masses derived from our measurement of CMB lensing are consistent with those derived from the clusters' SZ signatures.