R. Durrett et Ea. Perkins, Rescaled contact processes converge to super-Brownian motion in two or more dimensions, PROB TH REL, 114(3), 1999, pp. 309-399
We show that in dimensions two or more a sequence of long range contact pro
cesses suitably rescaled in space and time converges to a super-Brownian mo
tion with drift. As a consequence of this result we can improve the results
of Bramson, Durrett, and Swindle (1989) by replacing their order of magnit
ude estimates of how close the critical value is to I with sharp asymptotic
s.