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Seminars
Contact :
Hèléne Berthoumieux
Tel : +33 (0) 1 40 79 xx xx
Paddy Royall
Tel : +33 (0) 1 40 79 xx xx
Gulliver seminars take place on Mondays at 11:30 AM in the F304 room, and typically last one hour including questions. The seminars are in English, and the scientific topics are mainly those studied in the laboratory.
Gulliver Seminar : Séverine Atis (CNRS, Poitiers)
Stratified fluids such as the ocean or the atmosphere can carry internal gravity waves that can transport energy and momentum over large distances, and affect large-scale circulation patterns. When the density stratification is not uniform, internal waves can exhibit resonances, tunneling, and frequency-dependent transmissions. In the ocean, the interplay between heat diffusion and salt diffusion can lead to extended regions with spatially periodic density profiles called thermohaline staircases. In this talk, we report on the experimental observation of band gaps for internal gravity waves in a laboratory setting with similar periodic stratification. We also find the existence of surface states that are exponentially localized near interfaces and controlled by boundary conditions. Using analytical and numerical modeling, we show that these are formally equivalent to topological surface states found in one-dimensional topological insulators and photonic crystals. Our results suggest that energy transport by internal waves could be profoundly altered by the presence of periodic stratifications that occur in regions such as the Arctic Ocean.
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Seminars (2)
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Gulliver Seminar : Haim Diamant (Tel Aviv University)
Lundi 29 avril de 11h30 à 12h30 - C162
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Gulliver seminar : Matthew Turner
Lundi 13 mai de 11h30 à 12h30 - C162
The audience is often heterogeneous - because of the wide range of scientific topics covered in the lab - so planning a talk for a broader audience would be preferred. The seminar is in English, and speakers are thus invited to prepare their slides in English.
The seminar starts at 11:30 AM. The speaker is asked to arrive in the lab at least 15 minutes in advance to set up their computer. The talks last typically 45 minutes, and are followed by a discussion time.