Constraining the Mass-Richness Relationship of redMaPPer Clusters with
  Angular Clustering
  The potential of using cluster clustering for calibrating the mass-observable
relation of galaxy clusters has been recognized theoretically for over a
decade. Here, we demonstrate the feasibility of this technique to achieve high
precision mass calibration using redMaPPer clusters in the Sloan Digital Sky
Survey North Galactic Cap. By including cross-correlations between several
richness bins in our analysis we significantly improve the statistical
precision of our mass constraints. The amplitude of the mass-richness relation
is constrained to 7% statistical precision. However, the error budget is
systematics dominated, reaching an 18% total error that is dominated by
theoretical uncertainty in the bias-mass relation for dark matter halos. We
perform a detailed treatment of the effects of assembly bias on our analysis,
finding that the contribution of such effects to our parameter uncertainties is
somewhat greater than that of measurement noise. We confirm the results from
Miyatake et al. (2015) that the clustering amplitude of redMaPPer clusters
depends on galaxy concentration, and provide additional evidence in support of
this effect being due to some form of assembly bias. The results presented here
demonstrate the power of cluster clustering for mass calibration and cosmology
provided the current theoretical systematics can be ameliorated.
