Occupation Time Limit Theorems for the Voter Model
Cox, J. Theodore ; Griffeath, David
Ann. Probab., Tome 11 (1983) no. 4, p. 876-893 / Harvested from Project Euclid
Let $\{\eta^\theta_s(x)\}, s \geq 0, x \in Z^d$ be the basic voter model starting from product measure with density $\theta(0 < \theta < 1).$ We consider the asymptotic behavior, as $t \rightarrow \infty$, of the occupation time field $\{T^x_t\}_{x \in Z^d}$, where $T^x_t = \int^t_0 \eta^\theta_s(x) ds$. Our main result is that, properly scaled and normalized, the occupation time field has a (weak) limit field as $t \rightarrow \infty$, whose covariance structure we compute explicitly. This field is Gaussian in dimensions $d \geq 2$. It is not Gaussian in dimension one, but has an "explicit" representation in terms of a system of coalescing Brownian motions. We also prove that $\lim_{t \rightarrow \infty} T^x_t/t = \theta$ a.s. for $d \geq 2$ (the result is false for $d = 1$). A striking feature of the behavior of the occupation time field is its elaborate dimension dependence.
Publié le : 1983-11-14
Classification:  Voter model,  coalescing random walks,  occupation times,  central limit theorems,  strong laws,  moments,  semi-invariants,  Ursell functions,  60K35
@article{1176993438,
     author = {Cox, J. Theodore and Griffeath, David},
     title = {Occupation Time Limit Theorems for the Voter Model},
     journal = {Ann. Probab.},
     volume = {11},
     number = {4},
     year = {1983},
     pages = { 876-893},
     language = {en},
     url = {http://dml.mathdoc.fr/item/1176993438}
}
Cox, J. Theodore; Griffeath, David. Occupation Time Limit Theorems for the Voter Model. Ann. Probab., Tome 11 (1983) no. 4, pp.  876-893. http://gdmltest.u-ga.fr/item/1176993438/