We consider Markov processes [eta]t [subset of] d in which (i) particles die at rate [delta] [greater-or-equal, slanted] 0, (ii) births from x to a neighboring y occur at rate 1, and (iii) when a new particle lands on an occupied site the particles annihilate each other and a vacant site...

We analyze the limiting behavior of the densities ρA(t) and ρB(t) for the diffusion controlled chemical reaction A + B → inert. We prove that for equal initial densities ρA(0)=ρB(0) there is a change in behavior from d ⩽4, where ρA(t)=ρB(t)∼Ctd4, to d⩾4, where ρA(t)=ρB(t)∼Ct as...