Extreme Events and Metastability in Fluids and Waves
Tobias Grafke, CIMS


Rare but extreme events often have a dramatic influence on the statistics of stochastic systems, but are notoriously hard to handle
both analytically and numerically. In particular in fluid dynamics with its overwhelmingly large number of coupled degrees of freedom,
the stochastic forcing interacts with nonlocal nonlinear terms to create coherent structures inducing strong non-Gaussianity. I will
present how large deviation theory provides a rigorous framework to quantify these effects, allowing to predict the emergence of extreme
events, and similarly transition events in metastable fluid systems (as observed in e.g. atmospheric flows), as well as computing their
probability and statistics. The same methods apply to stochastic systems from other fields, such as ocean surface waves, active matter,
or reaction/diffusion systems.