Collective dynamics in animals

In a joint work with Philippe Peyla (LIPhy), we are interested in the spontaneous emergence of an ordered movement in a system composed of a large number of individuals. This intriguing and almost universal phenomenon can be found in bacteria on a sub-millimetre scale, in schools of fish stretching for kilometers, in human crowds or in flocks of birds. These collective movements result from local interactions between individuals from which large-scale patterns emerge. We approach this topic in an original way by seeking to understand the effect of a complex physical environment (flows, obstacles) on the collective swimming behavior of small aquarium fish (Blue Neon, Zebrafish). In particular, we aim to investigate the coupling between their social interactions and their hydrodynamic interactions, which have so far mainly been studied separately. To this end, we combine an experimental approach in a controlled environment providing quantitative measurements, in collaboration with Henda Djeridi (LEGI) with a numerical approach coupling the direct resolution of the 3D hydrodynamics with a cognitive model in collaboration with Thibaut Métivet (INRIA).