Local limits of conditioned marked Galton Watson trees

Abstract

We consider a Galton-Watson tree where each node is marked independently of each others with a probability depending on its outdegree. We give a complete picture of the local convergence of critical or sub-critical marked Galton-Watson trees conditioned on having a large number of marks. In the critical and sub-critical generic case, the limit is a random marked tree with an infinite spine, named marked Kesten's tree. We focus also on the non-generic case, where the local limit is a random marked tree with a node with infinite out-degree. This case corresponds to the so-called marked condensation phenomenon.