From random trajectories to random fields: Is fluid dynamics intrinsically random?
| Quand ? |
Le 20/07/2021, de 11:00 à 12:00 |
|---|---|
| Où ? | to be defined (online/on site) |
| Participants |
Simon Thalabard |
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This talk intends to briefly introduce the phenomenon of spontaneous (or intrinsic) stochasticity, a radical version of chaos emerging within turbulent environments. Roughly said, the spontaneous stochasticity describes the finite-time emergence of macroscopic randomness out of thermal fluctuations, due to the presence of some type of small-scale roughness.
I will specifically discuss two simple scenarios where spontaneous stochasticity can be identified, the super-diffusion of tracers advected by turbulent flows and the non-linear growth of certain fluid instabilities, among which the classical Kelvin-Helmholtz interfaces.
Those two examples substantiate the idea that fluids at high-Reynolds number are intrinsically random objects, be them observed from the Lagrangian or from the Eulerian perspective.