Turbulent transport in multifractal random flows
Simon Thalabard (MCF Univ. Côte d’Azur, INPHYNI, Nice)
| Quand ? |
Le 08/12/2025, de 11:00 à 12:00 |
|---|---|
| Où ? | Salle Condorcet |
| S'adresser à | Nicolas Plihon |
| Participants |
Simon Thalabard |
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The probabilistic description of Lagrangian dispersion by turbulence has its roots in the work of Taylor and Richardson who first promoted the idea that multiscale carrier flows may induce exotic transport properties. A general viewpoint is provided by considering transport in monofractal Gaussian random velocity ensembles---in particular the Markovian theory of Kraichnan flows introduced in the late sixties and later much developed in the nineties. While unrealistic in many ways, this setting reproduces various constitutive turbulent anomalies, from scaling and dissipation anomalies to the breakdown of the Lagrangian flow; It also highlights the physical interplay between spatial dimension, compressibility and spatial roughness of the advecting field.
In this talk, I will describe a possible extension of the Kraichnan flow theory to a multifractal setting, relying on a Markiovanized version of a random field first proposed by Robert and Vargas (and later refined). In particular, I will discuss a smoothing-by-intermittency effect, along with some analogies with the Liouville Brownian Motion, a canonical diffusion evolving within a random landscape, which was previously introduced in the context of Liouville quantum gravity.
This is joint work with André Considera.
In this talk, I will describe a possible extension of the Kraichnan flow theory to a multifractal setting, relying on a Markiovanized version of a random field first proposed by Robert and Vargas (and later refined). In particular, I will discuss a smoothing-by-intermittency effect, along with some analogies with the Liouville Brownian Motion, a canonical diffusion evolving within a random landscape, which was previously introduced in the context of Liouville quantum gravity.
This is joint work with André Considera.