Abstract
If R t is the position of the rightmost particle at time t in a one dimensional branching brownian motion, u(t, x)=P(R t >x) is a solution of KPP equation:
∂u∂t=12∂2u∂x2+f(u)
where f(u)=α(1-u-g(1-u)) g is the generating function of the reproduction law and α the inverse of the mean lifetime; if m=g′(1)>1 and g(0)=0, it is known that:
Rtt−→Pc0=2a(m−1)‾‾‾‾‾‾‾‾‾√, when t→+∞.
For the general KPP equation, we show limit theorems for u(t, ct+ζ), c>c 0 , ξ ∈ ℝ, t → +∞. Large deviations for R t and probabilities of presence of particles for the branching process are deduced:
http://static-content.springer.com.libproxy1.usc.edu/image/art%3A10.1007%2FBF00356108/MediaObjects/440_2006_BF00356108_f1.jpg
(where Z t denotes the random point measure of particles living at time t) and a Yaglom type theorem is proved. The conditional distribution of the spatial tree, given Z t (ct, +∞)>0, is studied in the limit as t → +∞.
Users
Please
log in to take part in the discussion (add own reviews or comments).