Balls-in-boxes duality for coalescing random walks and coalescing   Brownian motions
  We present a duality relation between two systems of coalescing random walks and an analogous duality relation between two systems of coalescing Brownian motions. Our results extends previous work in the literature and we apply it to the study of a system of coalescing Brownian motions with Poisson immigration. 
Steven N. Evans and Xiaowen Zhou