DR. SURHUD MORE

Halo assembly bias - the dependence of the large scale clustering amplitude of halos on secondary parameters other than the halo mass - is a well established prediction of the standard structure formation model. However it has been notoriously hard to confirm, observationally. The speaker will present a 6.6 sigma detection of difference in the clustering of redMaPPer galaxy clusters which share the same weak lensing mass. He will also present a detection of the splashback radius or the edges of redMaPPer galaxy clusters in observations. He will discuss some recent progress in understanding these observations in light of selection effects induced by optical cluster finding.