Contact process under renewals I

Abstract

Motivated by questions regarding long range percolation, we investigate a non-Markovian analogue of the Harris contact process in ${\mathbb{Z}}^d$: an individual is attached to each site $x\in {\mathbb{Z}}^d$, and it can be infected or healthy; the infection propagates to healthy neighbors just as in the usual contact process, according to independent exponential times with a fixed rate $\lambda$; nevertheless, the possible recovery times for an individual are given by the points of a renewal process with heavy tail; the renewal processes are assumed to be independent for different sites. We show that the resulting processes have a critical value equal to zero.

13 pages