Consider a catalytic super-Brownian motion $X =X^\Gamma$ with finite
variance branching. Here “catalytic ” means that branching of the
reactant $X$ is only possible in the presence of some catalyst. Our
intrinsic example of a catalyst is a stable random measure $\Gamma$ on
$\mathsf{R}$ of index $0 <\gamma<1$. Consequently, here the catalyst is
located in a countable dense subset of $\mathsf{R}$. Starting with a finite
reactant mass $X_0$ supported by a compact set, $X$ is shown to die in
finite time.We also deal with two other cases, with a power low catalyst and
with a super-random walk on $\mathsf{Z^d}$ withan i.i.d.catalyst.
¶ Our probabilistic argument uses the idea of good and bad historical
paths of reactant “particles ”during time periods $[T_n, T_{n
+1}$. Good paths have a signi .cant collision local time with the catalyst, and
extinction can be shown by individual time change according to the collision
local time and a comparison with Feller’s branching diffusion. On the
other hand, the remaining bad paths are shown to have a small expected mass at
time $T_{n +1}$ which can be controlled by the hitting probability of point
catalysts and the collision local time spent on them.
Publié le : 2000-04-14
Classification:
Catalytic super-Brownian motion,
historical superprocess,
critical branching,
finite time extinction,
finite time survival,
measure-valued branching,
random medium,
good and bad paths,
stopped measures,
collision local time,
comparison,
stopped historical superprocess,
branching rate functional,
super-random walk,
interacting Feller’s branching diffusion,
stable catalyst.,
60J80,
60J55,
60G57
@article{1019160254,
author = {Dawson, Donald A. and Fleischmann, Klaus and Mueller, Carl},
title = {Finite time extinction of superprocesses with catalysts},
journal = {Ann. Probab.},
volume = {28},
number = {1},
year = {2000},
pages = { 603-642},
language = {en},
url = {http://dml.mathdoc.fr/item/1019160254}
}
Dawson, Donald A.; Fleischmann, Klaus; Mueller, Carl. Finite time extinction of superprocesses with catalysts. Ann. Probab., Tome 28 (2000) no. 1, pp. 603-642. http://gdmltest.u-ga.fr/item/1019160254/