Limiting distributions for a class of super-Brownian motions with spatially dependent branching mechanisms

Abstract

In this paper we consider a large class of super-Brownian motions in $\mathbb{R}$ with spatially dependent branching mechanisms. We establish the almost sure growth rate of the mass located outside a time-dependent interval $(-\delta t,\delta t)$ for $\delta >0$. The growth rate is given in terms of the principal eigenvalue ${\lambda }_1$ of the Schödinger type operator associated with the branching mechanism. From this result we see the existence of phase transition for the growth order at $\delta =\sqrt{{\lambda }_1/2}$. We further show that the super-Brownian motion shifted by $\sqrt{{\lambda }_1/2}t$ converges in distribution to a random measure with random density mixed by a martingale limit.