Occupation times of branching systems with initial inhomogeneous Poisson states and related superprocesses

Abstract

The $(d,\alpha ,\beta ,\gamma )$-branching particle system consists of particles moving in $R^d$ according to a symmetric $\alpha$-stable Lévy process $(0<\alpha \le 2)$, splitting with a critical $(1+\beta )$-branching law $(0<\beta \le 1)$, and starting from an inhomogeneous Poisson random measure with intensity measure ${\mu }_{\gamma }(dx)=dx/(1+|x{|}^{\gamma }),\gamma \ge 0$. By means of time rescaling $T$ and Poisson intensity measure $H_T{\mu }_{\gamma }$, occupation time fluctuation limits for the system as $T\to \infty$ have been obtained in two special cases: Lebesgue measure ($\gamma =0$, the homogeneous case), and finite measures $(\gamma >d)$. In some cases $H_T\equiv 1$ and in others $H_T\to \infty$ as $T\to \infty$ (high density systems). The limit processes are quite different for Lebesgue and for finite measures. Therefore the question arises of what kinds of limits can be obtained for Poisson intensity measures that are intermediate between Lebesgue measure and finite measures. In this paper the measures ${\mu }_{\gamma },\gamma \in (0,d]$, are used for investigating this question. Occupation time fluctuation limits are obtained which interpolate in some way between the two previous extreme cases. The limit processes depend on different arrangements of the parameters $d,\alpha ,\beta ,\gamma$. Related results for the corresponding $(d,\alpha ,\beta ,\gamma )$-superprocess are also given.

References in corpus (5)

• Occupation time limits of inhomogeneous Poisson systems of independent particles
• Random rewards, fractional Brownian local times and stable self-similar processes
• Self-similar stable processes arising from high-density limits of occupation times of particle systems
• A functional CLT for the occupation time of a state-dependent branching random walk
• Occupation time fluctuations of Poisson and equilibrium branching systems in critical and large dimensions

Cited by in corpus (4)

• Particle systems with quasi-homogeneous initial states and their occupation time fluctuations
• Oscillatory Fractional Brownian Motion and Hierarchical Random Walks
• Equivalence of mean-field avalanches and branching diffusions: From the Brownian force model to the super-Brownian motion
• Fluctuations of the occupation times for branching system starting from infinitely divisible point processes