Total number of births on the negative half-line of the binary branching Brownian motion in the boundary case
Abstract
The binary branching Brownian motion in the boundary case is a particle system on the real line behaving as follows. It starts with a unique particle positioned at the origin at time $0$. The particle moves according to a Brownian motion with drift $\mu = 2$ and diffusion coefficient $\sigma^2 = 2$, until an independent exponential time of parameter $1$. At that time, the particle dies giving birth to two children who then start independent copies of the same process from their birth place. It is well-known that in this system, the cloud of particles eventually drifts to $\infty$. The aim of this note is to provide a precise estimate for the total number of particles that were born on the negative half-line, investigating in particular the tail decay of this random variable.
- Publication:
-
arXiv e-prints
- Pub Date:
- May 2021
- DOI:
- 10.48550/arXiv.2105.04896
- arXiv:
- arXiv:2105.04896
- Bibcode:
- 2021arXiv210504896C
- Keywords:
-
- Mathematics - Probability;
- 60J80;
- 60J65
- E-Print:
- Revised version correcting an error in the proof of Lemma 3.5