OxTalks will soon move to the new Halo platform and will become 'Oxford Events.' There will be a need for an OxTalks freeze. This was previously planned for Friday 14th November – a new date will be shared as soon as it is available (full details will be available on the Staff Gateway).
In the meantime, the OxTalks site will remain active and events will continue to be published.
If staff have any questions about the Oxford Events launch, please contact halo@digital.ox.ac.uk
Consider branching Brownian motion with absorption in which particles move independently as one-dimensional Brownian motions with drift $-\rho$, each particle splits into two particles at rate one, and particles are killed when they reach the origin. Kesten showed that this process dies out with probability one if and only if $\rho \geq \sqrt{2}$. In this talk I will focus on the subcritical case when $\rho > \sqrt{2}$ and consider two questions:
Firstly, can we obtain Yaglom type results? That is if we condition the process to be alive at large time $t$ what do we see? And if there is some sort of limit distribution, how does it behave when $\rho \searrow \sqrt 2$?
Second, we will study a question related to the so-called consistent maximal displacement: what is the inital position that a partcile must start from so that the process can survive until a large time $t$? We find that there is a phase transition, with the behavior changing when $t$ is of the order $\eps^{-3/2}$.
This is based on joint works with Jiaqi Liu, Bastien Mallein, and Jason Schweinsberg.