Two Critical Exponents for Finite Reversible Nearest Particle Systems
Liggett, Thomas M.
Ann. Probab., Tome 11 (1983) no. 4, p. 714-725 / Harvested from Project Euclid
Finite nearest particle systems are certain one parameter families of continuous time Markov chains $A_t$ whose state space is the collection of all finite subsets of the integers. Points are added to or taken away from $A_t$ at rates which have a particular form. The empty set is absorbing for these chains. In the reversible case, the parameter $\lambda$ is normalized so that extinction at the empty set is certain if and only if $\lambda \leq 1$. Let $\sigma(\lambda)$ be the probability of nonextinction starting from a singleton. In a recent paper, Griffeath and Liggett obtained the bounds $\lambda^{-1}(\lambda - 1) \leq \sigma(\lambda) \leq |\log \lambda^{-1}(\lambda -1)|^{-1}$ for $\lambda > 1$, and raised the question of determining the correct asymptotics of $\sigma(\lambda)$ as $\lambda \downarrow 1$. In the present paper, this question is largely answered by showing under a moment assumption that for $\lambda > 1, \sigma(\lambda)$ is bounded above by a constant multiple of $\lambda - 1$. In the critical case $\lambda = 1$, a similar improvement is made on the known bounds on the asymptotics as $n \rightarrow \infty$ of the probability that $A_t$ is of cardinality at least $n$ sometime before extinction. Similar results have been conjectured, but remain open problems in nonreversible situations--for example, for the basic one-dimensional contact process.
Publié le : 1983-08-14
Classification:  Interacting particle systems,  critical phenomena,  critical exponents,  reversible Markov chains,  60K35
@article{1176993516,
     author = {Liggett, Thomas M.},
     title = {Two Critical Exponents for Finite Reversible Nearest Particle Systems},
     journal = {Ann. Probab.},
     volume = {11},
     number = {4},
     year = {1983},
     pages = { 714-725},
     language = {en},
     url = {http://dml.mathdoc.fr/item/1176993516}
}
Liggett, Thomas M. Two Critical Exponents for Finite Reversible Nearest Particle Systems. Ann. Probab., Tome 11 (1983) no. 4, pp.  714-725. http://gdmltest.u-ga.fr/item/1176993516/