Random Walks Through Fock States of a Graph

I present process models for motion on a graph Γ(V,E) along its edges, motivated by examples. I build random sequences of edges and I derive sequences of Fock states. Therefore, I can distinguish two kinds of process steps, acceptance and rejection, comparable to stimulated and spontaneous emission. There is always at least one vertex, which represents the vacuum of the system. Rejections and vacuum are not visible in a quantum grand canonical ensemble.