Doubly Stochastic Yule Cascades (Part I): The explosion problem in the time-reversible case

Abstract

Motivated by the probabilistic methods for nonlinear differential equations introduced by McKean (1975) for the Kolmogorov-Petrovski-Piskunov (KPP) equation, and by Le Jan and Sznitman (1997) for the incompressible Navier-Stokes equations, we identify a new class of stochastic cascade models, referred to as doubly stochastic Yule cascades. We establish nonexplosion criteria under the assumption that the randomization of Yule intensities from generation to generation is by an ergodic time-reversible Markov chain. In addition to the cascade models that arise in the analysis of certain deterministic nonlinear differential equations, this model includes the multiplicative branching random walks, the branching Markov processes, and the stochastic generalizations of the percolation and/or cell aging models introduced by Aldous and Shields (1988) and independently by Athreya (1985).