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Simons Collaboration on Wave Turbulence Group Discussion
December 6, 2019 @ 9:00 am - December 7, 2019 @ 4:00 pm
SCHEDULE
Friday: 09-10 Breakfast
Friday: 10-12 G. Falkovich
Is there a weak wave turbulence?
Gregory will present/discuss what a theoretical physicist see as well-posed unsolved problems.
This will include,
- the probability distributions in phase space, profound difference between thermal equilibrium and turbulence;
- the character of temporal evolution towards the invariant measure;
- possibility of renormalization-group approach to wave turbulence, moving from weak to strong turbulence.
Friday: 2-4. N. Mordant
Wave turbulence in experimental/numerical/natural systems:
- effect of finite size,
- finite nonlinearity,
- finite dissipation,
- non-stationarity,
- non isotropy…
Can one reconcile real life and the theory ?
Saturday: 09-10 Breakfast
Saturday: 10-12 E. Tabak
“Questions in wave turbulence”. Topics will include:
- Some dichotomies: discrete vs. continuous spectra, weak vs. strong nonlinearity, thermal vs. intermittent regimes, local vs. global interactions.
- Symmetries and their consequences.
- A hierarchy of models, from multi-d to one-d to 2 coupled ODEs.
- Obtaining spectra from sparse observations.
Saturday: 2-4 P. Germain
“On the derivation of the kinetic wave equation”, and I will present/discuss what is known from a mathematical viewpoint on this question.
I would like to discuss two questions,
- If one considers NLS (say) on a compact domain, in the absence of forcing or dissipation, at which rate is energy transfered to high frequencies for t very large?
- Still considering NLS on a compact domain, in the absence of dissipation, two parameters condition the validity of the kinetic wave equation: the size of the domain and the size of the nonlinearity. For which range of these parameters is the kinetic wave equation valid?