Central Limit Theorems for Local Functionals of Dynamic Point Processes
Efe Onaran, Omer Bobrowski, Robert J. Adler
TL;DR
This work derives finite-dimensional central limit theorems for local interaction functionals of a dynamic point process on the torus, where points undergo birth-death events and Brownian motion with variance $\sigma^2$. The authors employ a marked Poisson process representation and Malliavin-Stein theory for $U$-statistics to obtain regime-dependent Gaussian limits: a slow regime yielding a weighted Ornstein-Uhlenbeck (OU) mixture, a moderate regime producing a Gaussian process with covariances involving functions $\zeta_j(\beta)$, and a fast regime where the time-integrated functional converges to Brownian motion. The analysis hinges on detailed covariance decompositions, Mecke-type counting lemmas for intersection patterns, and chaos expansions to control higher-order fluctuations. These results illuminate how birth-death dynamics and particle motion collectively shape motif-like local functionals in dynamic geometric graphs, with potential implications for mobile networks and dynamic percolation models. The paper also suggests a broader phase diagram with potential transitional regimes between the main three, inviting further study.
Abstract
We establish finite-dimensional central limit theorems for local, additive, interaction functions of temporally evolving point processes. The dynamics are those of a spatial Poisson process on the flat torus with points subject to a birth-death mechanism, and which move according to Brownian motion while alive. The results reveal the existence of a phase diagram describing at least three distinct structures for the limiting processes, depending on the extent of the local interactions and the speed of the Brownian motions. The proofs, which identify three different limits, rely heavily on Malliavin-Stein type CLTs for $U$-statistics on a representation of the dynamic point process via a distributionally equivalent marked point process.
