The Sunyaev-Zeldovich Signal of the maxBCG SDSS Galaxy Clusters in WMAP
  The Planck Collaboration measured the Sunyaev-Zel'dovich (SZ) decrement of
optically selected clusters from the Sloan Digital Sky Survey, finding that it
falls significantly below expectations based on existing mass calibration of
the maxBCG galaxy clusters. Resolving this tension requires either the data to
go up, or the theoretical expectations to come down. Here, we use data from the
Wilkinson Microwave Anisotropy Probe (WMAP) to perform an independent estimate
of the SZ decrement of maxBCG clusters. The recovered signal is consistent with
that obtained using Planck, though with larger error bars due to WMAP's larger
beam size and smaller frequency range. Nevertheless, this detection serves as
an independent confirmation of the magnitude of the effect, and demonstrates
that the observed discrepancy must be theoretical in origin.
