Coronae of product spaces and the Coarse Baum-Connes conjecture
  We study the coarse Baum-Connes conjecture for product spaces and product groups. We show that a product of CAT(0) groups, polycyclic groups and relatively hyperbolic groups which satisfy some assumptions on peripheral subgroups, satisfies the coarse Baum-Connes conjecture. For this purpose, we construct and analyze an appropriate compactification and its boundary, "corona", of a product of proper metric spaces. 
Tomohiro Fukaya, Shin-ichi Oguni
math.KT math.MG